ELECTRONIC DEVICES USING ORGANIC SMALL MOLECULE

SEMICONDUCTING COMPOUNDS

CLAIM OF PRIORITY

[0001] This application claims priority to provisional U.S. application no. 61/598,646, filed February 14, 2012, and to provisional U.S. application no. 61/603,039, filed February 24, 2012, each of which is incorporated by reference in its entirety.

BACKGROUND

[0002] Solution-processed organic photovoltaic devices (OPV) have emerged as a promising energy technology due to their ease of processing, low-cost, and ability to be fabricated onto light-weight flexible substrates. Polymer based OPV's have by far been the most studied, and power conversion efficiencies (PCE's) above 6% have recently been reported for polymenfullerene bulk heteroj unction (BHJ) devices. On the other hand, solution processed small molecule BHJ devices have received far less attention. Such molecular heterojunctions (MHJ) have several advantages over their polymer counterparts, in that small molecules have well defined structures, are easily functionalized, are mono-disperse, are readily purified, and do not suffer from batch-to-batch variations. Reports of efficient solution processed MHJ devices have recently emerged that have utilized merocyanine dyes, squaraine dyes, isoindigo, and diketopyrrolopyrrole based chromophores as the light harvesting donor component with a fullerene acceptor. PCE's have reached upwards of 4% for such devices. While these results are encouraging, there still exits a need for the development of novel discrete light harvesting materials. Key parameters for effective small molecule donors include having broad and efficient optical absorption that extends into the near-IR region to maximize photon absorption, deep HOMO levels from-5 to -5.5eV to maximize open circuit voltages, relatively planar structures for high charge carrier mobility, high solution viscosity and solubilizing side chains for solution to film processing.

Additionally, it is important that novel structures have facile and highly tunable syntheses to enable rapid and cheap generation of molecular libraries.

[0003] The present invention seeks to address the need for improved light harvesting molecules and molecular heterojunction devices by providing novel and advantageous materials and their use in such devices. SUMMARY

[0004] In one embodiment, the present invention is directed to organic non-polymeric semiconducting compounds containing halogen-substituted benzothiadiazole (BT, benzo[c][l,2,5]thiadiazole), benzooxadizaole (BO, benzo[c][l,2,5]oxadiazole), benzotriazole (B3N, 2H-benzo[d][l,2,3]triazole), benzoselenadiazole (BSe, benzo[c][l,2,5]selenadiazole), benzotelluradiazole (BTe, benzo[c][l,2,5]selenadiazole), 2,3-dihydroquinoxaline, and quinoxaline structures for use in heteroj unction devices, such as organic small molecule solar cells and transistors. In one embodiment, the present invention is directed to non-polymeric electron-donating and electron-accepting chromophores having a halogen-substituted benzothiadiazole (BT, benzo[c][l,2,5]thiadiazole), benzooxadizaole (BO,

benzo[c][l,2,5]oxadiazole), 2-substitutedbenzotriazole (B3N, 2H-benzo[d][l,2,3]triazole) core structure. In other embodiments, the present invention is directed to optoelectronic devices comprising a first electrode, a second electrode and an active layer between the the two electrodes containing a compound described herein.

[0005] Embodiments include electronic or optoelectronic devices using non-polymeric compounds, said compound incorporating one or more groups of Formula A:

Formula A

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, Ri is Η or a substituent; R ₂ is Η or a substituent; and R ₃ is Η or a substituent. Xi is Η or halogen and Yi is Η or halogen, where at least one of Xi and Yi is halogen. In some embodiments, both Xj and Yi are halogen.

[0006] Embodiments include compounds having Formula B: where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R -; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. In some embodiments, both Xi and Yi are halogen.

[0007] H]

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. Ai is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0008] Each Bi is independently selected from a an aryl or heteroaryl groups substituted with one, two, or more B ₂ .

[0009] Each B ₂ is independently selected from H, a substituent or

where Ri, R ₂ , R ₃ , R* and R ₅ are each independently H or a substituent;

[0010] H ₂ is selected from -B ₂ , -Ai-Bi, -A B _2, where p is 1, 2, or 3. Each X ₂ is independently H or halogen and each Y ₂ is independently H or halogen, where at least one of X ₂ and Y ₂ is halogen. In some embodiments, both Xi and Y _\ are halogen. In some embodiments, both X ₂ and Y ₂ are halogen. Each Ji is independently selected from a nonentity, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl groups, or

[0011] Q is a bivalent, trivalent, or tetravalent aryl or heteroaryl group or

[0012]

where each A] is independently selected from substituted or unsubstituted aryl or heteroaryl groups, such as C6-C30 substituted or unsubstituted aryl or heteroaryl groups, C ₆ -C ₂ o substituted or unsubstituted aryl or heteroaryl groups, and C ₆ -Cio substituted or unsubstituted aryl or heteroaryl groups.

[0013] With the proviso that Hi and H ₂ are not both -B ₂ .

4 BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Figure 1 shows geometry optimized structure, HOMO-LUMO orbital schemes and energies of an example compound using Density Functional Theory (B3LYP/6-31G** - Spartan Ί0, Wavefunction, Inc.)

[0101] Figure 2 shows absorption properties of an example compound in solution and film.

[0102] Figure 3 is a schematic illustration of an example device according to an embodiment of the invention..

[0103] Figure 4 shows J-V characteristics of an example device according to some embodiments of the invention.

[0104] Figure 5 shows absorption properties of an example compound in chloroform solution.

[0105] Figure 6 shows absorption properties of an example compound in a film on an ITO substrate, as cast, and after annealing at 125 °C.

[0106] Figure 7 shows a DSC curve for an example compound.

DETAILED DESCRIPTION

Definitions

[0107] The terms "alkyl" used alone or as part of a larger moiety (i.e. "alkoxy,"

"hydroxyalkyl," "alkoxyalkyl," and "alkoxycarbonyl") include both straight and branched saturated hydrocarbon chains containing one to sixteen carbon atoms (i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, or 16 carbon atoms), as well as cyclic structures. Alkyl groups may be independently defined between any two endpoints within this range, so that a particular alkyl group may have, for example, 1 to 12 carbons, 1 to 6 carbons, 1 to 4 carbons, 6-16 carbons, 6-12 carbons, and so forth. Examples of alkyl groups include methyl (Me), ethyl (Et), propyl (Pr) (including n-propyl ("Pr or n-Pr), isopropyl ('Pr or i-Pr) and cyclopropyl ( ^c Pr or c-Pr)), butyl (Bu) (including n-butyl ("Bu or n-Bu), isobutyl ('Bu or i-Bu), tert-butyl ( ^f Bu or t-Bu) and cyclobutyl (°Bu or c-Bu)), pentyl (Pe) (including n-pentyl) and so forth. Alkyl groups also include mixed cyclic and linear alkyl groups, such as cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, etc., so long as the total number of carbon atoms is not exceeded. The term "alkoxy" refers to an -O-alkyl radical, such as, for example -O-Me, -O-Et, -O-Pr, and so on. The term "hydroxyalkyl" refers to an alkyl group substituted with one or more hydroxyl, such as, for example, hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1,2-dihydroxyethyl, and so forth. The term "alkylthio" refers to an -S-alkyl group, such as, for example, example -S-Me, -S-Et, -S-Pr. The term "haloalkyl" means alkyl, substituted with one or more halogen atoms, such as trifluoromethyl, chloromethyl, 2,2,2-trifluoroethyl, 1, 1,2,2,2,-petanfluoroethyl, and so on, and includes "fluoroalkyl," where at least one carbon atom in the alkyl chain is substituted with fluorine, and perfluoro alkyl, where all hydrogen atoms on the alkyl chain are replaced with fluorine. The term "aminoalkyl" means alkyl, substituted with an amine group (NH ₂ ), such as, for example, aminomethyl, 1-aminoethyl, 2- aminoethyl, 3-aminopropyl and so forth. The term "alkoxyalkyl" refers to an alkyl group, substituted with an alkoxy group, such as, for example, methoxymethyl, ethoxymethyl, methoxyethyl, and so forth. As used herein, the term "alkylaminoalkyl" refers to an alkyl group substituted with an alkylamine group, such as, for example, N-methylaminomethyl, N,N-dimethylaminomethyl, Ν,Ν-methylpentylaminomethyl, 2-(N-methylamino)ethyl, 2- (N,N-dimethylamino)ethyl, and so forth.

[0108] The term "halogen" or "halo" means F, CI, Br, or I.

[0109] The term "nitro" means (-N0 ₂ ).

[0110] The term "hydroxy" or "hydroxyl" means -OH.

[0111] The term "amine" or "amino" used alone or as part of a larger moiety refers to unsubstituted (-NH ₂ ). The term "alkylamine" refers to mono- (-NRH) or di-substituted (-NR ₂ ) amine where at least one R group is an alkyl substituent, as defined above. Examples include methylamino (-NHCH ₃ ), dimethylamino (-N(CH ₃ ) ₂ ), The term "arylamine" refers to a mono (-NRH) or di-substituted (-NR ₂ ) amine, where at least one R group is an aryl group as defined below, including, for example, phenylamino, diphenylamino, and so forth. The term

"heteroarylamine" refers to a mono (-NRH) or di-substituted (-NR ₂ ) amine, where at least one R group is a heteroaryl group as defined below, including, for example, 2-pyridylamino, 3-pyridylamino and so forth. The term "aralkylamine" refers to a mono (-NRH) or di- substituted (-NR ₂ ) amine, where at least one R group is an aralkyl group, including, for example, benzylamino, phenethylamino, and so forth. The term "heteroaralkylamine" refers to a mono (-NRH) or di-substituted (-NR ₂ ) amine, where at least one R group is a

heteroaralkyl group. As used herein, the term "alkylaminoalkyl" refers to an alkyl group substituted with an alkylamine group. Analogously, "arylaminoalkyl" refers to an alkyl group substituted with an arylamine, and so forth, for any substituted amine described herein.

[0112] The term "alkenyl" used alone or as part of a larger moiety include both straight and branched chains containing at least one double bond and two to sixteen carbon atoms (i.e. 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1, 12, 13, 14, 15, or 16 carbon atoms), as well as cyclic, non-aromatic alkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl, etc. As used herein, alkenyl groups also include mixed cyclic and linear alkyl groups, such as cyclopentenylmethyl, cyclopentenylethyl,

cyclohexenylmethyl, etc., so long as the total number of carbon atoms is not exceeded. When the total number of carbons allows (i.e. more than 4 carbons), an alkenyl group may have multiple double bonds, whether conjugated or non-conjugated, but do not include aromatic structures. Examples of alkenyl groups include ethenyl, propenyl, butenyl, butadienyl, isoprenyl, dimethylallyl, geranyl and so forth.

[0113] The term "aryl" used alone or as part of a larger moiety, refers to mono-, bi-, tri-, or larger aromatic hydrocarbon ring systems having five to thirty members. Aryl groups may be independently defined between any two endpoints within this range, so that a particular aryl group may have, for example, 5 to 24 members, 6 to 24 members, 6 to 14 members, 10 to 30 members, and so forth. The term "aryl" may be used interchangeably with the term "aryl ring". "Aryl" also includes fused polycyclic aromatic ring systems in which an aromatic ring is fused to one or more rings. Examples include 1 -naphthyl, 2-naphthyl, 1-anthracyl and 2- anthracyl. Also included within the scope of the term "aryl", as it is used herein, is a group in which an aromatic ring is fused to one or more non-aromatic rings, such as in an indanyl, phenanthridinyl, or tetrahydronaphthyl, and including spiro compounds, such as

spirobi[fluorene], where the radical or point of attachment is on the aromatic ring. The term "aralkyl" refers to an alkyl substituent substituted by an aryl group. The term "aryloxy" refers to an -O-aryl group, such as, for example phenoxy, 4-chlorophenoxy and so forth. The term "arylthio" refers to an -S-aryl group such as, for example phenylthio, 4-chlorophenylthio, and so forth. The term "aryl" used alone or as part of a larger moiety also refers to aryl rings that are substituted such as, for example, 4-chIorophenyl, 3,4-dibromophenyl and so forth. An aryl group may have more than one substituent, up to the total number of free substitution positions. For example, an aryl group may have 1, 2, 3, 4, 5 or more substituents. The substituents may the same or different. Substituents on an aryl group include hydrogen, halogen, alkyl, alkenyl, nitro, hydroxyl, amino, alkylamino, alkoxy, and alkylthio, acyl, O- acyl, N-acyl, S-acyl as defined herein.

[0114] The term "heteroaryl", used alone or as part of a larger moiety, refers to

heteroaromatic ring groups having five to thirty members, in which one or more ring carbons (1 to 6, 1 to 4, 1 to 3, 1 to 2, or 1), are each replaced by a heteroatom such as N, O, S, or Si. Heteroaryl groups may be independently defined between any two endpoints within this range, so that a particular heteroaryl group may have, for example, 5 to 24 members, 6 to 24 members, 6 to 14 members, 10 to 30 members, and so forth. Examples of heteroaryl rings include 2-furanyl, 3-furanyl, N-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 3- isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-oxadiazolyl, 5-oxadiazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 1-pyrazolyl, 3-pyrazolyl, 4-pyrazolyl, 2- pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl, 4-pyrimidyl, 5-pyrimidyl, 3-pyridazinyl, 2- thiazolyl, 4-thiazolyl, 5-thiazolyl, 5-tetrazolyl, 2-triazolyl, 5-triazolyl, 2-thienyl, 3-thienyl, carbazolyl, benzimidazolyl, benzothienyl, benzofuranyl, indolyl, quinolinyl, benzotriazolyl, benzothiazolyl, benzooxazolyl, benzimidazolyl, isoquinolinyl, indazolyl, isoindolyl, acridinyl, benzoisoxazolyl. Other specific examples include thiophene, pyrrole, furan, phosphole, benzodithiophene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene, benzothiophene, isobenzothiophene, benzodithiophene,

cyclopentadithiophene, silacyclopentadiene, silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole, benzimidazole, benzofuran, isobenzofuran, thiadiazole, dithienopyrrole, dithienophosphole, and carbazole 9,9-RR'-9H-fluorene, 9-R-9H-carbazole, 3,3'-RR'silylene- 2,2 '-bithiophene, 3,3'RR'-cyclopenta[2, l-b:3,4-b']-dithiophene where R and R' = C _r C ₃ o alkyl or C ₆ -C ₃ o aryl. Also included within the scope of the term "heteroaryl", as it is used herein, is a group in which a heteroaromatic ring is fused to one or more aromatic or nonaromatic rings, including spiro compounds, where the radical or point of attachment is on the heteroaromatic ring. Examples include tetrahydroquinolinyl, tetrahydroisoquinolinyl, pyrido[3,4-d]pyrimidinyl, spirobi[dibenzo[b,c]silole], spirobi[cyclopenta[l,2-b:5,4- b'jdithiophene], or spirobi[silolo[3,2-b:4,5-b']dithiophene]. The term "heteroaryl" may be used interchangeably with the term "heteroaryl ring" or the term "heteroaromatic." The term "heteroaralkyl" refers to an alkyl group substituted by a heteroaryl, such as, for example, 2- pyridylmethyl, 3-pyridylmethyl, 1-imidazolomethyl, 2-imidazolomethyl and so forth. The term "heteroaryloxy" refers to an -O-heteroaryl group. The term "heteroarylthio" refers to an -S-aryl group. A heteroaryl group may have more than one substituent, up to the total number of free substitution positions. For example, a heteroaryl group may have 1, 2, 3, 4, or 5 substituents. The substituents may the same or different. Substituents on a heteroaryl group include hydrogen, halogen, alkyl, alkenyl, nitro, hydroxyl, amino, alkylamino, alkoxy, and alkylthio, acyl, O-acyl, N-acyl, S-acyl as defined herein.

[0115] The term "acyl" refers to an *'-C(0)-alkyl," "C(0)-aryl," or "C(0)-heteroaryl" group. The term "O-acyl" refers to an "-0-C(0)-alkyl," "-0-C(0)-aryl," or "-O-C(O)- heteroaryl" group. The term "N-acyl" refers to an "-NR-C(0)-alkyl," "-NR-C(0)-aryl," or "- NR-C(0)-heteroaryl" where R is an alkyl, hydroxyl, or alkoxy group. The term "S-acyl" refers to "-S-C(0)-alkyl," "-S-C(0)-aryl," or "-S-C(0)-heteroaryl." The term "N-O-acyl" refers to an "N-0-C(0)-alkyl," "N-0-C(0)-aryl," or "N-0-C(0)-heteroaryl" group.

[0116] As used herein, a "substituted" structure refers to a chemical structure where a hydrogen atom has been replaced by a substituent. A "substituent" is a chemical structure that replaces a hydrogen atom on the substituted structure, and may be, independently, any chemical moiety defined previously. When present, multiple substituents may be the same or different. The term "substituent" does not imply that the substituent is smaller than the substituted structure. In some embodiments, a "substituent" may be halogen, F, N0 ₂ , CN, acyl, O-acyl, S-acyl, N-acyl, alkyl, haloalkyl, substituted or unsubsituted aryl, substituted or unsubstituted heteroaryl, alkenyl, alkoxy, alkylthio, alkylamine, arylamine, or hydroxy.

[0117] "Polymer" or "polymeric molecule" is defined herein as a structure containing at least eight repeating units. A "non-polymeric" molecule is a molecule containing seven or fewer repeating units. Thus, monomers, dimers, trimers, tetramers, pentamers, hexamers, and heptamers are non-polymeric molecules for the purposes of this disclosure. Interruption of a repeating unit "resets" the count of subunits for the purposes of this disclosure; thus, for example, for a molecule such as Formula 6:

when n is 5, the molecule is considered to have two separate five-subunit pieces, that is, it is comprised of two pentamers of thiophene, and is not considered a decamer or 10- subunit polymer of thiophene.

[0118] Non-polymeric molecules have a discrete molecular weight, while polymeric molecules usually have a distribution of molecular weights due to varying numbers of monomers that are incorporated into the growing chain during polymerization. Thus, in one embodiment, a preparation of a non-polymer molecule will be characterized by a single molecular weight (where the molecular weight is averaged only over isotopic variation due to differing isotopes such as hydrogen, deuterium, carbon- 12, carbon- 13, etc.). In contrast, preparations of a polymeric molecule will have a distribution of molecular weights due to varying numbers of monomers in the final polymer, where the molecular weight is an average over each individual polymeric species present in a given preparation (measured in either number-average molecular weight or weight-average molecular weight). [0119] In some embodiments, compositions of the non-polymeric molecules described herein are not part of a mixture of oligomers or polymers. In other words, in some embodiments, compositions comprising the non-polymer molecules described herein will not contain oligomers or polymers having a repeating structure in common with the non- polymeric molecules described herein. In some embodiments, the non-polymer molecule is substanially pure, i.e. the molecules described herein may be greater than 90% pure, greater than 95% pure, or greater than 98% pure.

Small molecules

[0120] Some embodiments of the current invention provide several advantages for preparation of optoelectronic devices. The organic materials described are non-polymeric allowing for synthesis and purification to be more repeatable than organic polymers. Unlike polymers, the organic materials described are discrete mono-disperse small molecules which allows for their exact structure to be known and reproduced.

[0121] Organic compounds described herein may have favorable frontier molecular orbital levels (HOMO and LUMO) to accept and transport holes and electrons. The organic small molecule compounds described also have favorable frontier molecular orbital levels (HOMO and LUMO) for use as electron donating materials in organic solar cell devices with fullerene, methanofullerene, rylene diimides or related π-conjugated organic electron acceptors. In addition, the organic small molecule chromophores described have favorable frontier molecular orbital levels (HOMO and LUMO) for use as electron accepting materials in organic solar cell devices with thiophene or phenyl based π-conjugated organic electron donors.

[0122] The optical properties of the compounds are also very good. The organic small molecule chromophores described have broad absorption spectra that absorb ultraviolet, visible, and near infrared radiation. The absorption spectra of the organic small molecule chromophores described have a favorable spectral overlap with the terrestrial solar spectrum, making them excellent light harvesting materials for organic solar cells.

[0123] The compounds are also readily handled in solution, as the organic small molecules described retain good solubility in many common organic solvents. This allows solution processing during the preparation of the optoelectronic devices.

[0124] While solution processing may be advantageous for its ease of handling and low cost, vapor deposition can also be used, or mixtures of said molecules with other components, which are suitable for use in such a method (e.g., vacuum deposition, physical vapor deposition, chemical vapor deposition).

[0125] Embodiments of the invention include compounds having Formula B:

B

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ )2-, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -0(=Ν-¾)-; ¾ is H or a substituent; R ₂ is H or a substituent; R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. In some embodiments, both Xi and Yi are halogen.

[0126] Hi

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. Ai is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene, w // ,or W // W /

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group. Each Bi is independently selected from a an aryl or heteroaryl groups substituted with one, two, or more B ₂ . Each B ₂ is independently selected from H, a substituent or

where Ri, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0127] H ₂ is selected from -B ₂ , -A, -Bi, -A,-B _2> where p is 1, 2, or 3, n is an integer between 0 and 5, inclusive, and m is an integer between 0 and 5, inclusive, and l<m+n<5. Each X ₂ is independently H or halogen and each Y ₂ is independently H or halogen, where at least one of X ₂ and Y ₂ is halogen. Each Ji is independently selected from a nonentity, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl groups

Q is a bivalent, trivalent, or tetravalent aryl or heteroaryl group or

W /Γ ^Α2 \ //

Li is sel

where each A _\ is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene, ,or where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0128] In Formula B, Hi and H ₂ are not both -B ₂ .

[0129] In some compounds according to Formula B, M is S. In some compounds according to Formula B, all X _n and Y _n substituents are halogen. In other words, Xj, Yi, X ₂ ,Y ₂ are all halogen. In some compounds according to formula B, all X _n and Y _n substituents are fluorine.

[0130] In some compounds according to Formula B, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula B, M is -N(Rj)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula B, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0131] In some compounds according to Formula B, H ₂ is

where p is 1, and Hi and L] are the same.

[0132] In some compounds according to Formula B, Hi is

[0133] In some compounds according to formula B, Bi is substituted by one B ₂ .

[0134] In some compounds according to formula B, each Ji is a nonentity.

[0135] In some compounds according to formula B, H is

where p is 1, both Ji are both nonentities, and Li and Hi are the same and are both

where Bj is substituted by one B ₂ .

[0136] Some compounds according to formula B have Formula II, shown below:

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent; . Each n is an integer between 0 and 5, inclusive, and each m is an integer between 0 and 5, inclusive, and l<m+n<5. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Y] is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. Q is a bivalent aryl or heteroaryl group. Each Bi is independently selected from a an aryl or heteroaryl groups. Each B ₂ is independently selected from H or a substituent; where Ri, R ₂ , R ₃ , and R4 are each independently H or a substituent.

[0137] In some compounds according to Formula II, B] is a substituted or unsubstituted thiophene.

[0138] In some compounds according to Formula II, Q may be thiophene, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene, benzothiophene, isobenzothiophene, benzodithiophene, cyclopentadithiophene, silacyclopentadiene,

silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole, benzimidazole, benzofuran, isobenzofuran, thiadiazole, dithienopyrrole, dithienophosphole and carbazole 9,9-RR'-9H- fluorene, 9-R-9H-carbazole, 3,3'-RR'silylene-2,2'-bithiophene, 3,3'RR'-cyclopenta[2, l- b:3,4-b']-dithiophene, where R and R' = Ci-C ₃₀ alkyl or C ₆ -C ₃ o aryl. [0139] In some compounds according to formula II, Bi may be, independently, thiophene, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene, benzothiophene,

isobenzothiophene, benzodithiophene, cyclopentadithiophene, silacyclopentadiene, silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole, benzimidazole, benzofuran, isobenzofuran, thiadiazole, perfluorylbenzene, and carbazole.

[0140] In some compounds according to Formula II, Q is 3,3'-RR'silylene-2,2'- bithiophene and R and R' are both C1-C30 alkyl.

[0141] In some compounds according to Formula II, Q is

[0142] In some compounds according to Formula II, n+m=l .

[0143] In some compounds according to Formula II, B ₂ is alkyl.

[0144] In some compounds according to Formula II, Q is 3,3'-RR'silylene-2,2'- bithiophene and R and R' are both C1-C30 alkyl, Bi is thiophene, n+m=l, and B ₂ is alkyl.

[0145] For example, the compound according to Formula II may have the structure

[0146] In some compounds according to Formula II, M is S. In some compounds according to Formula II, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ ,Y ₂ are all halogen. In some compounds according to formula II, all X _n and Y _n substituents are fluorine.

[0147] In some compounds according to Formula B, H ₂ is

where p is 1, both Ji are both nonentities, and Li and Hi are the same and are both -B ₂ or -A,-B ₂ .

[0148] Some compounds according to Formula B have Formula I:

Formula I

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent . Xj is H or halogen and Yj is H or halogen, where at least one of X] and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. Q is a bivalent aryl or heteroaryl group.

[0149] Each L ₂ is independently -B ₂ or -Ai-B ₂ . Each Ai is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group;

[0150] Each B ₂ is independently selected from H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5, and where Rj, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0151] In some compounds according to Formula I, Q may be substituted or unsubstituted thiophene, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene,

spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene,

benzothiophene, isobenzothiophene, benzodithiophene, cyclopentadithiophene,

silacyclopentadiene, silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole,

benzimidazole, benzofuran, isobenzofuran, thiadiazole, dithienopyrrole, dithienophosphole, and carbazole 9,9-RR'-9H-fluorene, 9-R-9H-carbazole, 3,3'-RR'silylene-2,2'-bithiophene, 3,3'RR'-cyclopenta[2, l-b:3,4-b']-dithiophene where R and R' = Ci-C ₃₀ alkyl or C ₆ -C ₃₀ aryl.

[0152] In some compounds according to Formula I, each L ₂ is -Ai-B ₂ .

[0153] In some compounds according to Formula I, and Ai is independently substituted or unsubstituted thiophene, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene,

benzothiophene, isobenzothiophene, benzodithiophene, cyclopentadithiophene,

silacyclopentadiene, silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole,

benzimidazole, benzofuran, isobenzofuran, thiadiazole, perfluorylbenzene, and carbazole.

[0154] In some compounds according to Formula I each L ₂ is B ₂ .

[0155] In some compounds according to Formula I B ₂ is

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5; and where Ri, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0156] In some compounds according to Formula B, Hi and H ₂ are the same.

[0157] In some compounds according to Formula I, M is S. In some compounds according to Formula I, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ ,Y ₂ are all halogen. In some compounds according to Formula I, all X _n and Y _n substituents are fluorine.

[0158] In some compounds according to Formula I, M is -N(Ri)- where R _\ is H, alkyl, or haloalkyl. In some compounds according to Formula I, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula I, M is -N(Rj)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0159] Some compounds according to Formula B have Formula III:

Formula III where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R s ¾ is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen.

[0160]

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5.

[0161] Each Aj is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

W // A ₂ -:

,or w // where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group..

Each Bi is independently selected from a an aryl or heteroaryl groups optionally substituted with one, two, or more B ₂ Each B ₂ is independently selected from a substituent or

where Ri, R , R ₃ , 4 and R ₅ are each independently H or a substituent.

[0162] In some compounds according to formula III, H ₃ is -Ai-B ₂ , or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. Each Bi is independently selected from a an aryl or heteroaryl groups optionally B _2. Each B ₂ is independently selected

from a substituent

where Ri, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0163] In some compounds according to Formula III, A] is a DONOR, defined below.

[0164] In some compounds according to Formula III, H ₃ is -A]-B ₂ , or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 and A _\ is a DONOR, defined below. Each Bi is independently selected from a an aryl or heteroaryl groups optionally substituted with one, two, or more B ₂ .

Each B ₂ is independently selected from H, a substituent or

where Ri, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0165] In some compounds according to Formula III, B ₂ is H or a substituent.

[0166] In some compounds according to Formula III, B ₂ is

where Ri, R ₂ , R ₃ , R4 and R5 are each independently H or a substituent.

[0167] In some compounds according to Formula III, -Bj is

where J is selected from CH and N, and X is S, O, or NH when X is CH; and X is S when J is N.

[0168] In some compounds according to Formula III, -Bi is R6 is selected from aryl, perfluoroaryl, or C6-C30 aryl optionally perfluorinated.

[0169] In some compounds according to Formula III, all X _n and Y _n substituents are halogen. In other words, X _{l s} and Yi are all halogen. In some compounds according to Formula III, all X _n and Y _n substituents are fluorine.

[0170] In some compounds according to Formula III, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula III, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula III, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0171] Some compounds according to Formula III have Formulas 6, 7, or 8

where n is an integer from 0 to 5 inclusive; m is an integer from 0 to 5 inclusive. M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Rj)-, -C(R2) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. R ₇ is selected from H or a substituent. J is selected from CH and N. X is S, O, or NH when X is CH; and X is S when J is N. R6 is selected from aryl, perfluoroaryl, or C ₆ -C ₃ o aryl optionally perfluorinated or optionally substituted with one or more C1 -C16 alkyl groups.

[0172] In some compounds according to Formulas 6, 7, or 8, all X _n and Y _n substituents are halogen. In other words, Xi and Yj are all halogen. In some compounds according to Formulas 6, 7, or 8, all X _n and Y _n substituents are fluorine

[0173] In some compounds according to Formulas 6, 7, or 8, M is -N(Rj)- where R _\ is H, alkyl, or haloalkyl. In some compounds according to Formulas 6, 7, or 8, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formulas 6, 7, or 8, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0174] In some compounds according to Formula B, H ₂ is where p is 2.

[0175] In some compounds according to formula B, H ₂ is

[0176] where p is 2, and Hi and each Li are the same.

[0177] In some compounds according to formula B, H ₂ is

[0178] where p is 2, and Hi and each Li are the same and are -B ₂ or -Aj-B ₂ .

[0179] Some compounds according to Formula B have Formula IV-V:

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R -; R _{ is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and each Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen. Q is a trivalent aryl or heteroaryl group.

[0180] Each Ei is independently either nonentity, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl groups, or

[0181] Each L ₃ is, independently, -B ₂ or -Ai-B _2.

[0182] Each Aj is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0183] Each B ₂ is independently selected from, H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. Ri, R ₂ , R ₃ , R ₄ and R ₅ are each independently H or a substituent.

[0184] In some compounds according to Formula IV-V, Ei is a nonentity.

[0185] In some compounds according to Formula IV-V, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , Y ₂ , X ₃ , and Y ₃ are all halogen. In some compounds according to Formula IV-V, all X _n and Y _n substituents are fluorine. [0186] In some compounds according to Formula IV-V, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula IV-V, M is -N(Ri)- where R] is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula IV-V, M is -N(Ri)- where R] has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0187] Some compounds according to Formula IV-V have formula IVa

Formula IVa where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R,)-; R, is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and each Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen. Q is a trivalent aryl or heteroaryl group.

[0188] Each L ₃ is, independently, -B ₂ or -Ai-B ₂ .

[0189] Each A] is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0190] Each B ₂ is independently selected from, H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. And where Ri, R ₂ , R ₃ , 4 and R ₅ are each independently H or a substituent.

[0191] In some compounds according to Formula IVa, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , Y ₂ , X3, and Y ₃ are all halogen. In some compounds according to Formula IVa, all X _n and Y _n substituents are fluorine.

[0192] In some compounds according to Formula IVa, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula IVa, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula IVa, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0193] In some compounds according to Formula IV-V, each Ei is independently, a substituted or unsubstituted ar l, a substituted or unsubstituted heteroaryl group, or

[0194] Some compounds according to Formula IV-V have Formula Va:

Formula Va where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xj is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and each Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen. Q is a trivalent aryl or heteroaryl group.

Each Ei is independently a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl groups, or

[0195] Each L ₃ is, independently, -B ₂ or -Aj-B ₂ .

[0196] Each A] is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0197] Each B ₂ is independently selected from, H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. R _{l s} R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0198] In some compounds according to Formula B, H ₂ is

Ρ

where p is 3. [0199] In some compounds according to formula B, H ₂ is

P

where p is 3, and Hi and each Li are the same.

[0200] In some compounds according to formula B, ¾ is

P

where p is 3, and Hj and each Lj are the same and are -B ₂ or -A]-B ₂ .

[0201] In some compounds according to Formula Va, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , Y2, X3, and Y3 are all halogen. In some compounds according to Formula Va, all X _n and Y _n substituents are fluorine.

[0202] In some compounds according to Formula Va, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula Va, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula Va, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0203] Some compounds according to Formula B have Formula VI- VII:

is a tetravalent aryl or heteroaryl group selected from

(2, 2',7,7'-yl-9,9'-spirobi[fluorene]),

(3,3',7,7'-yl-5,5'-spirobi[dibenzo[b,d]silole]),

(2,2',6,6'-yl-4,4"-spirobi[cyclopenta[l,2-b:5,4-b']dithiophe ne]), or

(2,2 ^, ,6,6'-yl-4,4'-spirobi[silolo[3,2-b:4,5-b']dithiophene] );

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(R])-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of X] and Yi is halogen. X ₂ is H or halogen and Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen. X ₄ is H or halogen and Y ₄ is H or halogen, where at least one of X4 and Y ₄ is halogen

[0204] Each Fi is independently either nonentity, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl groups, or

[0205] Each L is, independently, -B ₂ or -Ai-B ₂ .

[0206] Each Ai is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0207] Each B ₂ is independently selected from, H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. And where Ri, R ₂ , R ₃ , Ri and R ₅ are each independently H or a substituent.

[0208] In some compounds according to Formula VI-VII, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , Y ₂ , X ₃ , Y ₃ , X ₄ , and Y ₄ are all halogen. In some compounds according to Formula VI-VII, all X _n and Y _n substituents are fluorine.

[0209] In some compounds according to Formula VI-VII, M is -N(Rj)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula VI-VII, M is -N(Ri)- where R] is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula VI-VII, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0210] Some compounds according to Formula VI-VII have Formula Via:

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R,)-; ¾ is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xj is H or halogen and Y] is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen. X ₄ is H or halogen and Y ₄ is H or halogen, where at least one of X4 and Y ₄ is halogen

[0211] Each Fi is independently either nonentity, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl groups, or

[0212] Each L ₄ is, independently, -B ₂ or -Ai-B ₂ .

[0213] Each Ai is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0214] Each B ₂ is independently selected from, H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. And where Ri, R ₂ , R ₃ , R ₄ and R ₅ are each independently H or a substituent.

[0215] In some compounds according to Formula Via, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , Y ₂ , X ₃ , Y ₃ , X ₄ , and Y ₄ are all halogen. In some compounds according to Formula Via, all X _n and Y _n substituents are fluorine.

[0216] In some compounds according to Formula Via, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula Via, M is -N(Rj)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula Via, M is -N(Ri)- where R _\ has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0217] Some compounds according to Formula VI-VII have Formula Vila:

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of X] and Yi is halogen. X ₂ is H or halogen and Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen. X ₄ is H or halogen and Y ₄ is H or halogen, where at least one of X4 and Y ₄ is halogen

[0218] Each Fj is independently either nonentity, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl groups, or

[0219] Each L ₄ is, independently, -B ₂ or -Aj-B ₂ .

[0220] Each A] is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene,

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group.

[0221] Each B ₂ is independently selected from, H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. R _; , R ₂ , R ₃ , and R ₅ are each independently H or a substituent.

[0222] In some compounds according to Formula Vila, all X _n and Y _n substituents are halogen. In other words, Xj, Yi, X ₂ , Y ₂ , X ₃ , Y ₃ , X ₄ , and Y ₄ are all halogen. In some compounds according to Formula Vila, all X _n and Y _n substituents are fluorine.

[0223] In some compounds according to Formula Vila, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula Vila, M is -N(Ri)- where R _\ is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula Vila, M is -N(Ri)- where R] has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0224] In some compounds according to Formula B, Q is a DONOR.

[0225] In some compounds according to Formula B, H ₂ is

P

where p is I, and Hi and Li are the same, and both Hi and Li are -B _2j where B ₂ is independently selected from, H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. And where Rj, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0226] In some compounds of formula B, Q is a DONOR, H ₂ is where p is 1, each Ji is a nonentity, and Hi and Li are the same, and both Hi and Li are -B _2> where B ₂ is independently sele

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5. R _1} R ₂ , R ₃ , R4 and R5 are each independently H or a substituent.

[0227] Some compounds of Formula B have Formula 1:

where n is an integer from 0 to 5 inclusive, M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ )2-C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. R ₇ is selected from H or a substituent.

[0228] In some comp

P

where p is 1, Hi and Li are the same, and both Hi and L _\ are

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 where each B] is independently selected from an aryl or heteroaryl groups substituted with one, two, or more B ₂ , Each B ₂ is independently selected from H, a substituent or

where Ri, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

"Bi

[0229] In some compounds of formula B, Hi and Li may be

[0230] In some compounds of formula B, Bi is substituted by two B ₂ .

[0231] In some comp

where p is 1, each Jj is a nonentity, Hi and Li are the same, and both Hi and Li are

and each Bi is an aryl or heteroaryl group substituted with two B ₂ , where each B ₂ is independently selected from H, a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5 and where Rj, R ₂ , R ₃ , R4 and R5 are each independently H or a substituent.

[0232] In some compounds according to Formula 1, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , and Y ₂ are all halogen. In some compounds according to Formula 1, all X _n and Y _n substituents are fluorine.

[0233] In some compounds according to Formula 1, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula 1, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula 1, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0234] Some compounds of formula B have formula 2:

2 where n is an integer from 0 to 5 inclusive, M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(R,)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. R ₇ is selected from H or a substituent.

[0235] In some comp

P

where p is 1, Hi and Lj are the same, and both Hi and L] are -Ai

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 where each Bj is independently selected from an aryl or heteroaryl groups substituted with one, two, or more B _2. Each B ₂ is independently selected from H, a substituent or

where R _{l s} R ₂ , R ₃ , R ₄ and R ₅ are each independently H or a substituent.

[0236] In some compounds of formula B, B ₂ is H or a substituent.

[0237] In some compo

where p is 1, Hi and Lj -B ₂ or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 where each Bi is independently selected from an aryl or heteroaryl groups substituted with one, two, or more B _2. Each B ₂ is independently selected from H or a substituent.

[0238] In some compounds of formula B, -Ai -B ₂ is

where J is selected from CH and N, and X is S, O, or NH when X is CH; and X is S when J is N.

[0239] In some compounds

where J is selected from CH and N, and X is S, O, or NH when X is CH; and X is S when J is N.

[0240] In some compounds according to Formula 2, all X _n and Y _n substituents are halogen. In other words, Xi, Y|, X ₂ , and Y ₂ are all halogen. In some compounds according to Formula 2, all X _n and Y _n substituents are fluorine.

[0241] In some compounds according to Formula 2, M is -N(Ri)- where R _\ is H, alkyl, or haloalkyl. In some compounds according to Formula 2, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula 2, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0242] Some compounds of formula B have formula 3:

where n is an integer from 0 to 5 inclusive, J is selected from CH and N and X is S, O, or NH when X is CH; and X is S when J is N. M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(R,)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen.

[0243] In some compounds of formula B, Bj is substituted by one B ₂ . [0244] In some compounds of formula B, B ₂ is diarylamine.

[0245] In some compounds of formula B, Bi is phenyl.

[0246] In some compounds of formula B, Ai is phenyl

[0247] In some compou

P

where p is 1, each Ji is a nonentity, Hi and Li are the same, and both Hi and Li are

-Ai-B ₂ where Aj is phenyl or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 where each Bi is phenyl substituted with one B ₂ . Each B ₂ is independently selected from H or diarylamine.

[0248] In some compounds according to Formula 3, all X _n and Y _n substituents are halogen. In other words, Xi, Y _ls X ₂ , and Y ₂ are all halogen. In some compounds according to Formula 3, all X _n and Y _n substituents are fluorine.

[0249] In some compounds according to Formula 3, M is -N(Ri)- where Ri is H, alk l, or haloalkyl. In some compounds according to Formula 3, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula 3, M is -Ν^)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0250] Some compounds of formula B have formula 4:

where n is an integer from 0 to 5 inclusive, J is selected from CH and N and X is S, O, or NH when X is CH; and X is S when J is N. M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(R,)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R])-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. R ₈ is C6-C ₃ o aryl optionally substituted with one or more Ci-Ci ₆ alkyl groups.

[0251] In some comp

where p is 1 , Hi and Li are the same, and both Hi and Li are both -Ai-Bi where each Ai is independently selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group except thiophene, w // ,or w // W //

where A ₂ is independently a substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group. Each Bi is independently selected from a an aryl or heteroaryl groups optionally B ₂ . Each B ₂ is independently selected

from a substituent

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 and Rj, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0252] In some compounds of formula B, A] is a DONOR.

[0253] In some compounds of formula B, H ₂ is

where p is 1, Hi and Li are the same, and both Hi and Li are both -A1-B1 where each Ai is a DONOR. Each Bi is independently selected from a an aryl or heteroaryl groups optionally ore B ₂ . Each B ₂ is independently selected from a substituent or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 and Rj, R ₂ , R ₃ , R4 and R ₅ are each independently H or a substituent.

[0254] In some comp

P

where p is 1, Q is a DONOR, each Ji is a nonentity, Hi and Li are the same, and both Hi and Li are -Aj-B] where each Ai is a DONOR. Each Bi is phenyl substituted with one, two, or more B _2i and each B ₂ is independently selected from a H or diarylamine.

[0255] In some compounds according to Formula 4, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , and Y ₂ are all halogen. In some compounds according to Formula 4, all X _n and Y _n substituents are fluorine.

[0256] In some compounds according to Formula 4, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula 4, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula 4, M is -N(R!)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1. [0257] Some compounds of formula B have formula 5:

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R,)-; R _x is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. R ₈ is C ₆ -C ₃ o aryl optionally substituted with one or more Ci-Ci ₆ alkyl groups.

[0258] In some compounds according to Formula B, H ₂ is

where p is 2.

[0259] In some compounds according to formula B, H ₂ is

P

where p is 2, and Hi and each Lj are the same.

[0260] In some compounds according to formula B, H ₂ is where p is 3, and Hi and each Li are the same and are -Ai-B ₂ .

[0261] In some compounds according to formula B, J] is

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 and Ri, R ₂ , R ₃ , and R4 are each independently H.

[0262] In some compounds according to formula B, Q is trivalent.

[0263] In some compounds according to formula B, Q is a trivalent aryl or heteroaryl group selected from

[0264] In some compounds according to formula B, H is

where p is 3, and Hi and each Li are the same and are -A]-B ₂ , where A _\ is a DONOR, and Bi is H or a substituent, and each Ji is a nonentity or

where n is an integer between 0 and 5, inclusive and m is an integer between 0 and 5, inclusive, and l<m+n<5 and Ri, R ₂ , R ₃ , and R ₄ are each independently H.

[0265] In some compounds according to Formula 5, all X _n and Y _n substituents are halogen. In other words, Xi, Yi, X ₂ , and Y ₂ are all halogen. In some compounds according to Formula 5, all X _n and Y _n substituents are fluorine.

[0266] In some compounds according to Formula 5, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula 5, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formula 5, M is -N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0267] Some compounds according to formula B have formula 9 or 10:

9 10

Where n is an integer from 0 to 5 inclusive; m is an integer from 0 to 5 inclusive. M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-Ri)-; Ri is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yj is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and each Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen.

[0268] In some compounds according to Formulas 9 or 10, all X„ and Y _n substituents are halogen. In other words, X _\ , Y _\ , X ₂ , Y ₂ , X ₃ , and Y ₃ are all halogen. In some compounds according to Formulas 9 or 10, all X„ and Y _n substituents are fluorine.

[0269] In some compounds according to Formulas 9 or 10, M is -N(Ri)- where Ri is H, alkyl, or haloalkyl. In some compounds according to Formula 1, M is -N(Ri)- where Ri is fluoroalkyl or perfluoroalkyl. In some compounds according to Formulas 9 or 10, M is

-N(Ri)- where Ri has the formula -C _n (H _x )(F _y ), where n is from 1 to 12, x+y = 2n+l, and y is at least 1.

[0270] Compounds according to Formula B may have, for example, Formula 1, Formula 2, Formula 3, Formula 4, Formula 5, Formula 6, Formula 7, Formula 8, Formula 9 or Formula 10 as defined herein. In Formulas 1-2-3-4-5, each DONOR moiety may be the same or different. In Formulas 6-7-8, each DONOR moiety may be the same or different. In Formulas 9-10, each DONOR moiety may be the same or different.



9 10

where n is an integer from 0 to 5 inclusive; m is an integer from 0 to 5 inclusive.

M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-,

-C(R ₂ ) ₂ -C(R ₃ )2-, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R,)-; ¾ is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. X _\ is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. X ₂ is H or halogen and each Y ₂ is H or halogen, where at least one of X ₂ and Y ₂ is halogen. X ₃ is H or halogen and each Y ₃ is H or halogen, where at least one of X ₃ and Y ₃ is halogen. R ₇ is selected from H or a substituent. J is selected from CH and N. X is S, O, or NH when X is CH; and X is S when J is N. R ₈ is C6-C30 aryl optionally substituted with one or more C1-C16 alkyl groups. Re is selected from aryl, perfluoroaryl, or C ₆ -C ₃₀ aryl optionally perfluorinated or optionally substituted with one or more -Cie alkyl groups.

[0271] As used throughout this application, DONOR is a heteroaromatic group, which may be, for example,

is C ₁ -C16 alkyl or C6-C20 aryl. R _]4 is selected from C ₁ -C16 alkyl, -O-C1-C16 alkyl,

-C(=0)-0-Ci -Ci6 alkyl, or -0-C(=0)-C _r Ci ₆ alkyl. R ₁₅ is selected from d-Cie alkyl, C ₆ -C ₂₀ unsubstituted aryl, or C ₆ -C ₂ o aryl substituted with one or more substituent.

[0272] In any compound described herein, a substituent may be, for example,

independently halogen, F, N0 ₂ , CN, acyl, O-acyl, S-acyl, N-acyl, alkyl, haloalkyl, substituted or unsubsituted aryl, substituted or unsubstituted heteroaryl, alkenyl, alkoxy, alkylthio, alkylamine, arylamine, or hydroxy. As such, in any compound described herein, unless otherwise specificed, B _2> R _{) >} R ₂ , R ₃ , R4, or R ₅ may be, independently, halogen, F, N0 ₂ , CN, acyl, O-acyl, S-acyl, N-acyl, alkyl, haloalkyl, substituted or unsubsituted aryl, substituted or unsubstituted heteroaryl, alkenyl, alkoxy, alkylthio, alkylamine, arylamine, or hydroxy.

[0273] In any compound described herein, at least one of Ri _, R ₂ , R ₃ , or R4 may be alkyl.

[0274] In any compound described herein, M may be S. In any compound described herein, M may be Se. In any compound described herein, M may be O.

[0275] In any compound described herein, all X„ and Y _n substituents may be halogen. In other words, every X and Y substituent, regardless of the subscript may be halogen.

[0276] In some compounds described herein, all X _n and Y _n substituents may be fluorine.

[0277] In any compound described herein, unless otherwise specificed, A] (when present) may be, for example, substituted or unsubstituted aryl or heteroaryl groups except thiophene, such as C ₆ -C ₃ o substituted or unsubstituted aryl or heteroaryl groups, C6-C20 substituted or unsubstituted aryl or heteroaryl groups, and C6-C10 substituted or unsubstituted aryl or heteroaryl groups. Examples of such groups include, but are not limited to, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene, benzothiophene, isobenzothiophene, benzodithiophene, cyclopentadithiophene, silacyclopentadiene,

silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole, benzimidazole, benzofuran, isobenzofuran, thiadiazole, dithienopyrrole, dithienophosphole and carbazole 9,9-RR'-9H- fluorene, 9-R-9H-carbazole, 3,3'-RR'silylene-2,2'-bithiophene, 3,3'RR'-cyclopenta[2, l- b:3,4-b']-dithiophene, where R and R' = C]-C ₃ o alkyl or C ₆ -C ₃ o aryl;

[0278] In any compound described herein, unless otherwise specificed, A ₂ (when present) may be, for example, substituted or unsubstituted aryl or heteroaryl groups, such as C ₆ -C ₃ o substituted or unsubstituted aryl or heteroaryl groups, C ₆ -C ₂ o substituted or unsubstituted aryl or heteroaryl groups, and C ₆ -Cio substituted or unsubstituted aryl or heteroaryl groups.

Examples of such groups include, but are not limited to, thiophene, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene, benzothiophene, isobenzothiophene, benzodithiophene, cyclopentadithiophene, silacyclopentadiene, silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole, benzimidazole, benzofuran, isobenzofuran, thiadiazole, dithienopyrrole, dithienophosphole and carbazole 9,9-RR'-9H-fluorene, 9-R-9H-carbazole, 3,3'-RR'silylene- 2,2'-bithiophene, 3,3'RR'-cyclopenta[2, l-b:3,4-b']-dithiophene, where R and R' = C _r C ₃₀ alkyl or C6-C30 aryl;

[0279] In any compound described herein, unless otherwise specificed, Bj may be substituted or unsubstituted aryl or heteroaryl groups, such as C6-C ₃ o substituted or unsubstituted aryl or heteroaryl groups, C ₆ -C ₂₀ substituted or unsubstituted aryl or heteroaryl groups, and C ₆ -Cio substituted or unsubstituted aryl or heteroaryl groups. Examples of aryl or heteroaryl groups include, but are not limited to, thiophene, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene, benzothiophene, isobenzothiophene, benzodithiophene, cyclopentadithiophene, silacyclopentadiene, silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, thiazolyl, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole, benzimidazole, benzofuran, isobenzofuran, thiadiazole, perfluorylbenzene, and carbazole.

[0280] In any compound described herein, unless otherwise specificed, Q may be substituted or unsubstituted aryl or heteroaryl groups, such as C6-C ₃₀ substituted or unsubstituted aryl or heteroaryl groups, C6-C20 substituted or unsubstituted aryl or heteroaryl groups, and C ₆ -Cio substituted or unsubstituted aryl or heteroaryl groups. Examples of aryl or heteroaryl groups include, but are not limited to, thiophene, pyrrole, furan, phenyl, phosphole, benzodithiophene, spirofluorene, spirothiophene, bithiophene, terthiophene, thienothiophene, dithienothiophene, benzothiophene, isobenzothiophene, benzodithiophene, cyclopentadithiophene, silacyclopentadiene, silacyclopentadienebithiophene, indole, benzene, naphthalene, anthracene, perylene, indene, fluorene, pyrene, azulene, pyridine, oxazole, thiazole, thiazine, thiazolyl, pyrimidine, pyrazine, imidazole, benzoxazole, benzoxadiazole, benzothiazole, benzimidazole, benzofuran, isobenzofuran, thiadiazole, perfluorylbenzene, carbazole, 9,9-RR'-9H-fluorene, 9-R-9H-carbazole, 3,3'-RR'silylene-2,2'-bithiophene, 3,3'RR'-cyclopenta[2, l-b:3,4-b']-dithiophene, where R and R' = C1-C30 alkyl or C ₆ -C ₃₀ aryl.

[0281] In some embodiments, the non-polymeric molecules descirbed herein have a solubility of at least about 0.1 mg/mL in an organic solvent, 1 mg/mL in an organic solvent, 5 mg/niL, 10 mg/mL in an organic solvent, 30 mg/mL in an organic solvent, or 100 mg/mL in an organic solvent. The organic solvent can be for example, chloroform, toluene,

chlorobenzene, methylene dichloride, tetrahydrofuran, or carbon disulfide.

Preparation

[0282] Compounds may be prepared using methods available to a chemist of ordinary skill. In short, compounds of the invention may be assembled by metal-catalyzed (including palladium-catalyzed) cross-coupling reactions between aromatic precursors. Suitable aromatic precursors include those bearing halogen substituents, which can be reacted with, for example, boronic acid or borane substituted aromatic compounds (Suzuki coupling), alkyl stannane substituted aromatic compounds (Stille coupling), alkysilane substituted aromatic compounds (Hiyama coupling), zinc substituted aromatic compounds (Negishi coupling), among others.

[0283] An example preparation is shown in the Examples below.

Device architectures, materials, and fabrication

[0284] Embodiments of the invention include electronic devices comprising a non-polymer compound comprising one or more groups of Formula A:

Formula A

where M is selected from sulfur (S), oxygen (O), selenium (Se), tellurium (Te), -N(Ri)-, -C(R ₂ ) ₂ -C(R ₃ ) ₂ -, -CR ₂ =CR ₃ -, -S(=0) ₂ -, -S(=0)-, -C(=0)-, -C(=S)-, or -C(=N-R,)-; ¾ is H or a substituent; R ₂ is H or a substituent; and R ₃ is H or a substituent. Xi is H or halogen and Yi is H or halogen, where at least one of Xi and Yi is halogen. In some embodiments, Formula A is a benzothiadiazole group, benzooxadizaole group, or benzotriazole group. In some embodiments, both Xi and Yi are halogen. In some embodiments, both Xi and Yi are fluorine.

[0285] Embodiments of the invention include organic electronic devices comprising any compound of formula B, as described herein. [0286] In some embodiments, the electronic device is a solar cell. In many solar cells, light passes though a transparent first electrode (such as ITO-coated glass), is absorbed by a donor: acceptor mixture, which results in the separation of electrical charges and migration of the charges to the electrodes, yielding a usable electrical potential.

[0287] Any electronic device described herein may have, for example, a first electrode, a second electrode and an active layer between the first and second electrode, where the active layer comprises the non-polymeric compound incorporating one or more groups of formula A or any compound according to formula B, described herein.

[0288] The first electrode may be made of materials such as, but not limited to, indium-tin oxide, indium-magnesium oxide, cadmium tin-oxide, tin oxide, aluminum- or indium-doped zinc oxide, gold, silver, nickel, palladium and platinum. In some embodiments, the first electrode has a high work function (4.3 eV or higher).

[0289] One electrode may be deposited onto a substrate. For example, the first electrode can be deposited onto a substrate, and the device can be fabricated by subsequent deposition of layers. However, the second electrode can be deposited onto a substrate, with subsequent deposition of layers. In some embodiments, the substrate may be transparent. The transparent substrate can be glass, plastic, or any other transparent material compatible with the electrode formed on the substrate.

[0290] The second electrode may be, for example, a metal electrode. Conducting metal oxides, such as indium tin oxide, zinc oxide, or cadmium oxide, can also be used as electrodes, as well as conducting organic materials, such as electrodes comprising graphene. For metal electrodes, the metal may be, for example, aluminum, silver or magnesium, but may be any metal. Nanowires such as silver nanowires or other nanostructured materials can also be used. If a transparent electrode is desired, very thin metallic layers of metals can also be used. In some embodiments, the device is annealed before and/or after evaporation of the metal electrode.

[0291] In any electronic device, one electrode may be transparent. For example, the first electrode may be transparent, allowing light to enter the device, but in some embodiments, the second electrode can be transparent. In some embodiments, both electrodes are transparent. In some embodiments, the transparent electrode may be indium tin oxide (ITO) coated onto a transparent substrate.

[0292] Any device may further include an electron-blocking, exciton-blocking, or hole- transporting layer. The electron-blocking, exciton-blocking or hole-transporting layer may be adjacent to the first electrode. In some embodiments, the hole transporting layer may be, for example, poly(3,4-ethylene dioxythiophene:poly(styrenesulfonate) (PEDOT:PSS). Other hole transporting materials, such as polyaniline (with suitable dopants), or N,N'-diphenyl-N,N'- bis(3-methylphenyl)[l,l '-biphenyl]-4,4'-diamine (TPD), nickel oxide, can be used.

[0293] In some embodiments, the layer may be an electron-blocking, exciton-blocking, or hole-transporting metal oxide. Electron-blocking, exciton-blocking, or hole-transporting metal oxides include, for example, M0O ₃ , Mo0 _3-x , V ₂ Os _-x , NiO, Ta ₂ O _s , Ag ₂ 0, CuO, Cu ₂ 0, Cr03 _-X , and W0 ₃ , where x is between 0.01 and 0.99, or between 0.1 and 0.9. Other suitable materials are described in Greiner, Mark T. et al., "Universal energy-level alignment of molecules on metal oxides," Nature Materials, DOI: 10.1038/NMAT3159 (November 6, 201 1).

[0294] Any device may further include a hole-blocking, exciton-blocking, or electron- transporting layer. In some embodiments, this layer is adjacent to the second electrode, and may optionally be deposited on top of the donor-acceptor film in order to block holes or excitons, act as an optical buffer, or otherwise benefit the electrical characteristics of the device. 2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline can act as a hole-blocking or exciton- blocking material, while 4,4',4"-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine and polyethylene dioxythiophene can act as exciton-blocking materials. Other materials that can be used between the second electrode and the active layer are titanium suboxide, ZnO, Cs ₂ C0 ₃ , and Zr0 ₃ . Additional materials suitable for use are described in Greiner, Mark T. et al., "Universal energy-level alignment of molecules on metal oxides," Nature Materials, DOI: 10.1038 NMAT3159 (November 6, 2011).

[0295] In any device, the active layer may further include an electron acceptor. The electron acceptor may be, for examplem, a fullerene such as [6,6]-phenyl C61-butyric acid methyl ester (PCBM), but may be a different fullerene (including, but not limited to, C71- PCBM), a tetracyanoquinodimethane, a vinazene, a perylene tetracarboxylic acid- dianhydride, a perylene tetracarboxylic acid-diimide, an oxadiazole, carbon nanotubes, or any other organic electron acceptor, such as those compounds disclosed in U.S. 2008/0315187.

[0296] In other embodiments, the electron acceptor is an inorganic acceptor selected from Ti0 ₂ (titanium dioxide), TiO _x (titanium suboxide, where x<2) and ZnO (zinc oxide). The titanium dioxide can be anatase, rutile, or amorphous. A titanium dioxide layer can be prepared by depositing a sol-gel precursor solution, for example by spincasting or doctorblading, and sintering at a temperature between about 300°C and 500°C. When an inorganic layer is used, component (c) of the optoelectronic device described above can be comprised of a layer of electron-donating chromophores of the general Formula I-VII and an inorganic electron-acceptor layer. Alternatively, the inorganic material can be dispersed in the electron-donating chromophores to create a single layer. Preparation of Ti0 ₂ for use in solar cells is described in Brian O'Regan & Michael Gratzel, Nature 353:737 (1991) and Serap Giines et al., 2008 Nanotechnology 19 424009.

[0297] When titanium suboxide according to the formula TiO _x where x<2, is used, x may follow the following relationships: 1 < x <1.98, 1.1 < x <1.9, 1.2 < x <1.8, or 1.3 < x <1. 8. X in the formula TiO _x can be, for example, <2, <1.98, <1.9, <1.8, <1.7, or <1.6.

[0298] In some embodiments, the device further includes a dielectric layer.

[0299] In some embodiments, the device further includes a third electrode.

[0300] Some devices may be tandem solar cells, such as those disclosed in US

2009/0126779. Tandem solar cells are arranged so that light which is not absorbed by a first solar cell passes to a second solar cell, where the second solar cell may have a smaller bandgap than the first solar cell in order to absorb electromagnetic radiation that cannot be usefully absorbed by the first solar cell.

[0301] Some devices may include passivating layers, such as those disclosed in US 2007/0221926 and US 2007/0169816.

[0302] Some devices may include optical spacer layers, such as those disclosed in US 2006/0292736.

[0303] One method of fabricating the optoelectronic device is as follows: A conductive, transparent substrate is prepared from commercially available indium tin oxide-coated glass and polystyrenesulfonic acid doped polyethylenedioxythiophene using standard procedures. A solution containing a mixture of the donor and acceptor materials is prepared so that the ratio of donor to acceptor is between 1:99 and 99: 1 parts by mass; or in some embodiments between 3:7 and 7:3 parts by mass. The overall concentration of the solution may range between 0.1 mg/mL and 100 mg /mL, but the range of 10 mg/mL and 30 mg/mL is particularly suitable for some embodiments. Non-polymeric molecules are used that have a solubility of at least about 0.1 mg/mL in an organic solvent, 1 mg/mL in an organic solvent, 5 mg/mL, 10 mg/mL in an organic solvent, 30 mg/mL in an organic solvent, or 100 mg/mL in an organic solvent. The organic solvent can be selected from chloroform, toluene, chlorobenzene, methylene dichloride, tetrahydrofuran, or carbon disulfide.

[0304] Useful solvents include chloroform, toluene, chlorobenzene, methylene dichloride, tetrahydrofuran, and carbon disulfide. However, the solvent used may be any solvent which dissolves or partially dissolve both donor and acceptor materials and has a non-zero vapor pressure. [0305] The solution of donor and acceptor is deposited by spin casting, doctor-blading, ink- jet printing, roll-to-roll coating, slot-dye coating, gravure coating, or any process which yields a continuous film of the donor-acceptor mixture such that the thickness of the film is within the range of 10 to 1000 nm, or between 50 and 150 nm in some embodiments.

[0306] In some embodiments, the layer of the donor and acceptor is cast from a solution comprising a solvent and the electron donor and the electron acceptor. The solvent can comprise chloroform, thiophene, trichloroethylene, chlorobenzene, carbon disulfide, a mixture of any of the foregoing solvents or any solvent or solvent mixture that dissolves both the donor and acceptor organic small molecule. The solvent can also include processing additives, such as those disclosed in US Patent Application Publication Nos. 2009/0032808, 2008/0315187, or 2009/0108255. For example, 1,8-diiodooctane (DIO) can be added to the solvent/donor/acceptor mixture in an amount of 0.1-10% by volume. The additive, such as 2% DIO, can be added to any organic solvent used to cast the layer of donor/acceptor, such as chloroform. The solvent can also include doping agents such as molybdenum trioxide

(M0O ₃ ). For example, M0O ₃ can be added to the solvent/donor/acceptor mixture in an amount of 0.1 - 10% by volume.

[0307] Finally, an electrode, such as a metal electrode, is deposited on top of the structure by thermal evaporation, sputtering, printing, lamination or some other process. Conducting metal oxides, such as indium tin oxide, zinc oxide, or cadmium oxide, can also be used as electrodes, as well as conducting organic materials, such as electrodes comprising graphene. For metal electrodes, the metal can be, for example, aluminum, silver or magnesium, but may be any metal. Nanowires such as silver nanowires or other nanostructures can also be used. If a transparent electrode is desired, very thin metallic sheets of metals can also be used. In some embodiments, the device is annealed before and/or after evaporation of the metal electrode.

[0308] Hole and electron mobilities are important parameters to consider in the

fabrication/function of bulk heteroj unction solar cells. For optimal device performance, a balance in the mobility of both charge carriers is desirable. The electron and hole mobilities may both be on the order of 10 ^"4 cm ² /Vs or higher. In some embodiments, the electron mobilities are on the order of 10 ^"3 cmVVs or higher. In some embodiments, the electron mobilities are on the order of 10 ^"4 cm ² /Vs or higher, and the hole mobilities are between 10 ^"8 cm ² /V s and 10 ^"4 cm ² /Vs or higher. In other embodiments, the electron mobilities are on the order of 10 ^"3 cm ² /Vs or higher, and the hole mobilities are between 10 ^~8 cm ² /Vs and 10 ^"4 cm ² /V s or higher. [0309] Optoelectronic devices of the present invention have excellent photovoltaic properties. In some embodiments, the power conversion efficiency (PCE) is at least 0.5%, at least 1.0%, at least 2.0%, or at least 3.0%. In some embodiments, the short circuit current density is greater than 3.0 mA/cm ² , but may be greater than 8 mA/cm ² in some embodiments. In some embodiments, the open circuit voltage is between 0.3 and 1.0 V or higher. In some embodiments, the device exhibits an external quantum efficiency of approximately 35% or greater between 300 and 800 nm.

[0310] The morphological properties of the dononacceptor films can be measured using atomic force microscopy or other surface-sensitive techniques. The films may have, for example, a root-mean-squared surface roughness of less than 1.0 nm or less than 0.5 nm in some embodiments.

[0311] For embodiments of the devices using an inverted device architecture, the first electrode can comprise Au or another material having a work function higher than the work function of the second electrode, while the second electrode can comprise an ITO substrate modified using a self-assembled monolayer of 3-aminopropyltrimethoxysiloxane or another material having a work function lower than the work function of the first electrode.

[0312] Figure 3 provides a schematic illustration of an electronic or optoelectronic device 100 according to an embodiments of the current invention. The electronic or optoelectronic device 100 has a first electrode 102, a second electrode 104, spaced apart from said first electrode 102, and an active layer between said first electrode 102 and said second electrode 104. The active layer 106 can include any non-polymeric compound of formula A or formula B described herein. The first electrode 102 may be, for example, a transparent anode of indium-tin-oxide (ITO). The second electrode 104 may be, for example, a metal aluminum cathode.

[0313] In some embodiments, the electronic or optoelectronic device 100 can include a hole transporting layer 108 between the first electrode 102 and the active layer 106. The hole transporting layer 108 can be, for example, PEDOT:PSS. In some embodiments, the first electrode 102 can be formed on a substrate 110. The substrate 110 can be a transparent substrate in some embodiments. In some embodiments, the substrate 110 can be glass.

EXAMPLES

EXAMPLE 1

[0314] Synthesis <?/5,6-difluorobenzo[c][l,2,5]thiadiazoIe (F ₂ BT). To a 500 mL two- necked round bottom flask were added 4,5-difluorobenzene-l,2-diamine (10.0 g, 0.070 mol, Matrix Scientific), anhydrous CHC1 ₃ (250 mL) and anhydrous triethylamine (40 mL, 0.28 mol). The solution was stirred until the diamine was completely dissolved. Thionyl chloride (SOCI ₂ , 10.5 mL, 0.145 mol) was added dropwise using an addition funnel and the mixture heated to reflux for 5 h. The mixture was then cooled to room temperature, poured into 500 mL of distilled H ₂ 0, and then extracted with CH ₂ C1 (100 mLx3). The collected organic layers were combined and dried over MgS0 ₄ . The solvent was removed in vacuo and the resulting crude product purified by column chromatography using hexane/ethyl acetate (1 :4) as eluent. After removal of solvent the product was obtained as brownish-white crystalline solid. Recovered yield: 10.65 g (90%). 1H NMR (600MHz, CDC1 ₃ ): δ 7.73 (t, 2H, J _F . _H = 12.0 Hz, 12.0 Hz).

[0315] Synthesis o/5,6-difluoro-4,7-diiodobenzo[c] [l,2,5]thiadiazole (I ₂ F ₂ BT). in a 500 mL two-necked round-bottom flask A mixture of 2 (2.70 g, 15 mmol) I ₂ (15 g, 60 mmol) and fuming sulfuric acid (75 mL) was stirred at 60°C for 24 hours. After cooling to room temperature, the reaction mixture was slowly poured into a 500 mL beaker with crushed ice. Chloroform (CHCI ₃ ) was added and the mixture was transferred into a 1 L separatory funnel and washed with distilled water (150 mL><3), followed by 1M NaOH solution several times to remove excess iodine and finally washed with saturated NaHC0 ₃ . The organic layer was then dried over MgS0 ₄ . After the filtration and solvent removal, the yellow paper-like solid product was used without further purification. Recovered yield: 3.52 g (52.6%).

[0316] ^«/Ae5W o 7,7'-(4,4-bis(2-ethylhexyI)-4H-silolo[3,2-b:4,5-b']dithiophe ne-2,6- diyl)bis(5,6-difluoro-4-iodobenzo[c][l,2,5]thiadiazoIe). In 250 ml two-necked round bottom flask 5,5'- )w(trimethylstannyl)-3,3'-Di-2-ethylhexylsilylene-2,2'-bithi ophene (Me ₃ Sn-SDT _E H-SnMe ₃ , 2.0 gram, 2.68 mmol), 5,6-difluoro-4,7- diiodobenzo[c][l,2,5]thiadiazole (I ₂ F ₂ BT, 2.30 g, 5.5 mmol) were dissolved in anhydrous toluene (60 ml) and the resulting mixture degassed for 15 minutes. Pd(PPh ₃ ) ₄ (310 mg, 0.268 mmol, 10 mol%) was then added and the mixture degassed for another 2 minutes after which it was heated to 110°C for 16 hours under N ₂ gas. Upon cooling to room temperature, the volatiles were removed in vacuo to give the crude product as a dark reddish-brown solid. 100 ml of acetone was added to crude product and the mixture stirred for 30 minutes and the solids filtered. The material was then loaded onto silica and purified by flash chromatography using CH ₂ C1 ₂ as eluent. After fraction collection and solvent removal a purplish red solid was obtained. The solid was slurried in acetone (200 mL), stirred for 30 minutes, and filtered. The solid was washed with copious amounts of acetone and then dried under vacuum for 24 hours. The product was collected as dark reddish-maroon solid. Recovered yield: 1.8 g

(66%). 1H NMR (600 MHz, CDC1 ₃ ): 7.54 (dt, 2H, SDT-CH), 2.81 (m, ³ J _H -H = 7 HZ, 4H, Th- G%), 1.70 (m, ³ JH-H = 7 HZ, 4H, CH), 1.60 (m, 2Η, CH), 1.40 (m, 4Η, C¾), 1.34 (m, 14Η, C¾), 1.27 (m, 10Η, G¾), 1.15 (m, 4Η, SiG¾), 0.91 (m, 8Η, G¾), 0.87 (m, 10Η, G¾).

[0317] 5^«iAe5w o/7,7'-(4,4-bis(2-ethyIhexyI)-4H-silolo[3,2-b:4,5-b']dithiop hene-2,6- diyl)bis(5,6-difluoro-4-(5'-hexyl-[2,2'-bithiophen]-5-yl)ben zo[c][l,2,5]thiadiazole). In 250 two-necked round bottom flask 7,7'-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5- b']dithiophene-2,6-diyl)bis(5,6-difluoro-4-iodobenzo[c][l,2, 5]thiadiazole) (IF ₂ BT-SDT _EH - IF ₂ BT, 1.5 grams, 1.48 mmol) and 5'-Hexyl-2,2'-bithiophene-5-boronic acid pinacol ester (773 mg, 3.26 mmol) were dissolved in anhydrous toluene (60 mL), and degassed for 15 minutes. To this mixture was added Pd ₂ dba ₃ (140 mg, 0.153 mmol, 10 mol%) and H*P(f- Bu ₃ )BF ₄ ^" (180 mg, 0.620 mmol, 40 mol%) and the mixture then degassed for another 2 minutes. Finally, degassed 2M K ₂ C0 ₃ (20 mL) was added and the mixture heated to 110°C for 16 hours under N ₂ . Upon cooling the reaction mixture was poured into methanol (MeOH, 300 mL) and stirred for 30 minutes. The precipitate that formed was collect by filtration and washed with copious amounts of MeOH and distilled H ₂ 0. The crude product was first purified by flash chromatography using with methylene chloride (CH ₂ C1 ₂ ) as eluent. After fraction collection and solvent removal a maroon solid was obtained. The product was then further purified by soxhlet extraction with methanol and acetone to removed monomers and catalyst residues. The remaining solid in the thimble was stirred in 50 ml of diethyl ether for 30 minutes, filtered and then dried under vacuum for 24 hours. The product (NET4C-F2) was collected as a maroon solid. Recovered yield: 0.620 g (33%). 1H NMR (600 MHz, CDC1 ₃ ): δ 8.33 {t, 2H, J _F .H = 12 Hz, SDT-CH), 8.18 (d, ³ J _H . _H = 3.6 Hz, 2H, Th-CH), 7.21 (d, ³ JH-H = 6 Hz, 2H Th-CH), 7.13 (d, ³ J„.H = 6 Hz, 2H Th-CH), 6.72 (d, ³ J _H -H = 5 Hz, 2H Th-CH), 2.81 (m, ³ J _H . _H = 7 Hz, 4H Th-C%), 1.70 (h, ³ J _H -„= 7 Hz, 4H, CH), 1.60 (m, 2Η, CH), 1.40 (m, 4Η, CH ₂ ), 1.34 (m, 14Η, C¾), 1.27 (m, 10Η, C¾), 1.15 (m, 4Η, SiC¾), 0.91 (m, 8Η, CH ₅ ), 0.87 (m, 10Η, G¾).

EXAMPLE 2 - Determination ofHOMO-LUMO values

[0318] Calculations: All calculations were performed using the Spartan ' 10 program. Optimized gas-phase structures were obtained using the density functional theory (DFT) method B3LYP in conjunction with 6-31G(d,p) basis set, i.e., B3LYP/6-31G(d,p).

[0319] Figure 1 shows highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) values calculated using the method above.

EXAMPLE 3 - General procedures for fabrication of devices

[0320] Device Fabrication: Solar cells were fabricated on patterned ITO-coated glass substrates. The ITO-coated glass substrates were first cleaned with detergent, ultrasonicated in water, acetone and isopropyl alcohol, and subsequently dried overnight in an oven.

M0O ₃ films were thermally evaporated onto UV-Ozone cleaned ITO substrates at a rate of 0.1 A s-' under a vacuum of about 1 ^χ 10 ^-6 torr. The thickness of the MoOj film is

approximately 13 nm. A solution containing a mixture of NET4C-F2:[70]PCBM

in chlorobenzene at a total solids concentration of 35 mg ml ^-1 was spin-cast on top of the M0O5 films at a spin speed of 1500 rpm. The composition of the active layer includes a 60:40 ratio of NET4C-F2:[70]PCBM with and without 1,8-diiodooctane.

[0321] In other devices, PEDOT:PSS 4083 was spin cast onto UV-ozone cleaned ITO then thermally annealed for 30 m at 150 °C. The solution containing a mixture of NET4C- F2:[70]PCBM in chlorobenzene at a total solids concentration of 35 rng mf ¹ was spin-cast on top of the PEDOT:PSS films at a spin speed of 1500 rpm with the same composition as previously described.

[0322] The active layers were heated at 70 °C for 10 min to evaporate any residual solvent. Finally, the aluminum cathode (-100 nm) was deposited through a shadow mask by thermal evaporation under a vacuum of about 1 x 10 torr. The active area of the device was

15.28 mm ² . The devices were finally annealed at 90 °C for 2 m.

[0323] Device testing. Current density-voltage (J-V) characteristics were measured using a Keithley 2602A Source Measure Unit while illuminated with a simulated 100 mWcnf ² AM 1.5G light source using a 300W Xe arc lamp with an AMI .5 global filter. Solar-simulator illumination intensity was measured using a standard silicon photovoltaic with a protective KG1 filter calibrated by the National Renewable Energy Laboratory.

[0324] For organic photovoltaic devices, the overall PCE is determined by the equation:

PCE = (Voc*Jsc*FF) Pin where Voc is the open circuit voltage, Jsc is the short-circuit current density, FF is the fill factor and Pin is the incident light power. Voc is the voltage at which there is no current flow in the device while the Jsc is the amount of current flowing when no voltage is applied. Values are derived from the graph shown in Figure 4 and are represented in the table below.

[0325] DSC measurements. Thermal analysis was performed using a differential scanning calorimeter (DSC (Perkin Elmer DSC 6000). A 2.2 mg sample was weighed into an aluminum calorimetry pan and hermetically sealed. The sample was analyzed (3 sets of heating and cooling cycles) at a scan rate of 10 °C/min. Figure 7 shows data from the third heating/cooling cycle.

[0326] The disclosures of all publications, patents, patent applications and published patent applications referred to herein by an identifying citation are hereby incorporated herein by reference in their entirety. [0327] As described herein, all embodiments or subcombinations may be used in combination with all other embodiments or subcombinations, unless mutually exclusive.

[0328] Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is apparent to those skilled in the art that certain changes and modifications will be practiced. Therefore, the description and examples should not be construed as limiting the scope of the invention.

[0329] As described herein, all embodiments or subcombinations may be used in combination with all other embodiments or subcombinations, unless mutually exclusive.