LIN WEI HSIANG (KR)
SCHROEDER MARC (DE)
NA GEUMBI (KR)
| WO2020096761A1 | 2020-05-14 | |||
| WO2020076882A1 | 2020-04-16 | |||
| WO2016024196A1 | 2016-02-18 | |||
| WO2015004563A1 | 2015-01-15 | |||
| WO2015004563A1 | 2015-01-15 |
| US8399761B2 | 2013-03-19 | |||
| US20090302311A1 | 2009-12-10 |
| Claims 1. A composition, comprising an organic semiconducting polymer and a crosslinking agent, wherein the organic semiconducting polymer and the crosslinking agent can undergo crosslinking reaction under thermal and/or light exposure. 2. The composition according to claim 1, wherein the organic semiconducting polymer is selected from the group consisting of thiophene-based conjugated polymer and diketo-pyrrole-pyrrole (DPP)-based conjugated polymer. 3. The composition according to claim 1, wherein the organic semiconducting polymer comprises repeating units of the formula wherein R1 and R2 may be the same or different and are selected from hydrogen, a C1-25-alkyl group, an alkenyl group, an alkynyl group, an allyl group, which can be substituted one to three times with C1-4-alkyl; or a cycloalkyl group, which can be substituted one to three times with C1-8-alkyl; a and b are independently of each other an integral number in the range of 0 to 10, Ar1 and Ar2 in each case may be the same or different and independently of each other stand for a group of formula p stands for 0, 1 , 2, 3 or 4; R3 in each case may be the same or different and is selected from C1-25-alkyl group or C1-18 alkoxy; and R4 and R4’ independently from each other stand for hydrogen, C1-C25 alkyl group or C1-C18 alkoxy. 4. The composition according to claim 1, wherein the organic semiconducting polymer have the following structure: wherein R1, R2, R3 and R4 may be the same or different and are selected from hydrogen, a C1-25-alkyl group, an alkenyl group, an alkynyl group, an allyl group, which can be substituted one to three times with C1-4-alkyl; or a cycloalkyl group, which can be substituted one to three times with C1-8-alkyl; Ar1, Ar2, Ar3 and Ar4 in each case may be the same or different and independently of each other stand for a group of benzene, substituted benzene, thiophene and substituted thiophene; a, b, c and d are independently of each other an integral number in the range of 0 to 10, preferably in the range of 1 to 5 and more preferably in the range of 1 to 3; and n is a number in the range of 0.05 to 0.95 and m is a number in the range of 0.95 to 0.05, preferably n is a number in the range of 0.1 to 0.9 and m is a number in the range of 0.9 to 0.1, and more preferably n is a number in the range of 0.15 to 0.85 and m is a number in the range of 0.85 to 0.15. 5. The composition according to claim 1, wherein the organic semiconducting polymer has the following structure: wherein n is a number in the range of 0.05 to 0.95 while m is a number in the range of 0.95 to 0.05; preferably, n is a number in the range of 0.5 to 0.9 while m is a number in the range of 0.5 to 0.1 ; more preferably, n is a number in the range of 0.7 to 0.85 while m is a number in the range of 0.3 to 0.15. 6. The composition according to claim 5, wherein n=0.8 and m=0.2. 7. The composition according to claim 1, wherein the crosslinking agent is selected from the group consisting of diazirine, phenyl azide, fluoro-phenyl azide and acyl az- ide. 8. The composition according to claim 1, wherein the crosslinking agent is of formula wherein a is 0, 1 or 2, b is 1 , 2, 3 or 4, c is 0 or 1 , d is O, 1 , 2, 3 or 4, e is 0, 1 or 2, x is 0, 1 or 2, y is 0, 1 or 2, z is 0, 1 or 2, w is 0, 1 or 2, n is 0 or 1, Ar1 and Ar2 are independently from each other and at each occurrence an aromatic or heteroaromatic moiety, which can be substituted with one or more substituent Ra selected from the group consisting of C1-20-alkyl, C5-8-cycloalkyl, C6-14-aryl, 5 to 12 membered heteroaryl, COOR10, CONR10R11, COR10, SO3R10, CN, NO2, halogen, OR10, SR10, NR10R11, OCOR10 and NR10COR11, wherein R10 and R11 are inde- pendently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, C6- 14-aryl or 5 to 12 membered heteroaryl, wherein C1-20-alkyl and C5-8-cycloalkyl can be substituted with one or more substitu- ents Raa at each occurrence selected from the group consisting of phenyl, COOR12, CONR12R13, COR12, SO3R12, CN, NO2, halogen, OR12, SR12, NR11R12, OCOR12 and NR12COR13, wherein C6-14-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent Rab at each occurrence selected from the group consist- ing of Ci-10-alkyl, cyclopentyl, cyclohexyl, COOR12, CONR12R13, COR12, SO3R12, CN, NO2, halogen, OR12, SR12, NR12R13, OCOR12 and NR12COR13, wherein R12 and R13 are independently from each other and at each occurrence C1 -10- alkyl, cyclopentyl, cyclohexyl or phenyl, and wherein at least two adjacent Ar1, at least two adjacent Ar2 , and/or Ar1 and Ar2 , both connected to L2 or if c = 0 to each other, can be additionally linked by one or more La , wherein La is a linking moiety B, L1 and L3 are independently from each other and at each occurrence or wherein R3 and R4 are independently from each other and at each occurrence H , C1-20-alkyl, C5-8-cycloalkyl, C6-i4-aryl, 5 to 12 membered heteroaryl, COOR20, CONR20R21, COR20, SO3R20, CN, NO2, or halogen, wherein R20 and R21 are independently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, C6-14-aryl or 5 to 12 membered heteroaryl, wherein C1-20-alkyl and C5-8-cycloalkyl can be substituted with one or more substitu- ents Rb at each occurrence selected from the group consisting of phenyl, COOR22, CONR22R23, COR22, SO3R22, CN, NO2, halogen, OR22, SR22, NR22R23, OCOR22 and NR22COR23, wherein C6-14-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent Rc at each occurrence selected from the group consisting of C1 -10- alkyl, cyclopentyl, cyclohexyl, COOR22, CONR22R23, COR22, SO3R22, CN, NO2, halo- gen, OR22, SR22, NR22R23, OCOR22 and NR22COR23, wherein R22 and R23 are independently from each other and at each occurrence C1 -10- alkyl, cyclopentyl, cyclohexyl or phenyl, or, if L1 or L3 are R3 and R4 together with the C-atoms to which they are attached form a 5 to 7- membered non-aromatic ring system, L2 is a linking moiety A, and R1 and R2 are independently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, C6-14-aryl, 5 to 12 membered heteroaryl, COOR30, CONR30R31, COR30, SO3R30, CN, NO2, halogen, OR30, SR30, NR30R31, OCOR30 or NR30COR31, wherein R30 and R31 are independently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, C6-14-aryl or 5 to 12 membered heteroaryl, wherein C1-20-alkyl and C5-8-cycloalkyl can be substituted with one or more substitu- ents Rd at each occurrence selected from the group consisting of phenyl, COOR32, CONR32R33, COR32, SO3R32, CN, NO2, halogen, OR32, SR32, NR32R33, OCOR32 and NR32COR33 , wherein C6-14-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent Re at each occurrence selected from the group consisting of C1 -10- alkyl, cyclopentyl, cyclohexyl, COOR32, CONR32R33, COR32, SO3R32, CN, NO2, halo- gen, OR32, SR32, NR32R33, OCOR32 and NR32COR33, wherein R32 and R33 are independently from each other and at each occurrence C1 -10- alkyl, cyclopentyl, cyclohexyl or phenyl; wherein linking moiety A is selected from the group consisting of C1 -10-alkylene, C2-10- alkenylene, C5-8-cycloalkylene, C1-4-alkylene-C5-8-cycloalkylene-C1-4-alkylene, C1-4- alkylene-phenylene-C1-4-alkylene, C^-alkenylene-C5-8-cycloalkylene- C2-4-alkenylene and C2-4-alkenylene-phenylene-C2-4-alkenylene, which can be substituted with one or more substitutent Rf at each occurrence selected from the group consisting of C1-20- alkyl, C5-8-cycloalkyl, C6-14-aryl, 5 to 12 membered heteroaryl, COOR40, CONR40R41, COR40, SO3R40, CN, NO2, halogen, OR40, SR40, NR40R41, OCOR40 and NR40COR41, wherein R40 and R41 are independently from each other and at each occurrence H, C1 -10-alkyl, C5-8-cycloalkyl, C6-14-aryl or 5 to 12 membered heteroaryl, wherein C1-20-alkyl and C5-8-cycloalkyl can be substituted with one or more substitu- ents Rfa at each occurrence selected from the group consisting of phenyl, COOR42, CONR42R43, COR42, SO3R42, CN, NO2, halogen, OR42, SR42, NR42R43, OCOR42 and NR42COR43, wherein C6-14-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent Rfc at each occurrence selected from the group consisting of C1 -10- alkyl, cyclopentyl, cyclohexyl, COOR42, CONR42R43, COR42, SO3R42, CN, NO2, halo- gen, OR42, SR42, NR42R43, OCOR42 and NR42COR43, wherein R42 and R43 are independently from each other and at each occurrence C1 -10- alkyl, cyclopentyl, cyclohexyl or phenyl, and wherein one or more CH2 groups of C1 -10-alkylene, C1-4-alkylene, C2-10-alkenylene, C2- 4-alkenylene and/or C5-8-cycloalkylene can be replaced by C=O, (C=O)O, (C=O)NR50, SO2-NR50, NR50, NR50R51, O or S, wherein R50 and R51 are independently from each other and at each occurrence C1 -10- alkyl; and wherein linking moiety B is C1-4-alkylene, which can be substituted with one or more C1 -10-alkyl, wherein one or more CH2 groups of C1-4-alkylene can be replaced by C=O, (C=O)O, (C=O)NR60 , SO2-NR60, NR60, NR60R61, O or S, wherein R60 and R61 are independently from each other and at each occurrence C1 -10- alkyl. 9. The composition according to claim 1, wherein the crosslinking agent has the fol- lowing structure: wherein a is 0, 1 or 2, b is 1, 2, 3 or 4, c is 0 or 1 , d is 0, 1 , 2, 3 or 4, e is 0, 1 or 2, x is 0, 1 or 2, y is 0, 1 or 2, z is 0, 1 or 2, w is 0, 1 or 2, Ar1 and Ar2 are independently from each other and at each occurrence an aromatic or heteroaromatic moiety, which can be substituted with one or more substituent Ra selected from the group consisting of C1-20-alkyl, C5-8-cycloalkyl, C6-14-aryl, 5 to 12 membered heteroaryl, COOR10, CONR10R11, COR10, SO3R10, CN, NO2, halogen, OR10, SR10, NR10R11, OCOR10 and NR10COR11, wherein R10 and R11 are inde- pendently from each other and at each occurrence H, C1-20-alkyi, C5-8-cycloalkyl, C6- 14-aryl or 5 to 12 membered heteroaryl, wherein C1-20-alkyl and C5-8-cyclolkyl can be substituted with one or more substitu- ents Raa at each occurrence selected from the group consisting of phenyl, COOR12, CONR12R13, COR12, SO3R12, CN, NO2, halogen, OR12, SR12, NR11R12, OCOR12 and NR12COR13, wherein C6-14-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent Rab at each occurrence selected from the group consist- ing of Ci.io-alkyl, cyclopentyl, cyclohexyl, COOR12, CONR12R13, COR12, S03R12, CN, NO2, halogen, OR12, SR12, NR12R13, OCOR12 and NR12COR13, wherein R12 and R13 are independently from each other and at each occurrence C1 -10- alkyl, cyclopentyl, cyclohexyl or phenyl, and wherein at least two adjacent Ar1 , at least two adjacent Ar2, and/or Ar1 and Ar2, both connected to L2 or if c = 0 to each other, can be additionally linked by one or more La, wherein La is a linking moiety B, L1 and L3 are independently from each other and at each occurrence wherein R3 and R4 are independently from each other and at each occurrence H, Ci- 2o-alkyl, C5-8-cycloalkyl, C6-14-aryl, 5 to 12 membered heteroaryl, COOR20, CONR20R21, COR20, SO3R20, CN, NO2, or halogen, wherein R20 and R21 are independently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, C6-14-aryl or 5 to 12 membered heteroaryl, wherein C1-20- alkyl and C5-8-cycloalkyl can be substituted with one or more substituents Rb at each occurrence selected from the group consisting of phenyl, COOR22, CONR22R23, COR22, SO3R22, CN, NO2, halogen, OR22, SR22, NR22R23, OCOR22 and NR22COR23, wherein C6-14-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent Rc at each occurrence selected from the group consisting of C1 -10- alkyl, cyclopentyl, cyclohexyl, COOR22, CONR22R23, COR22, SO3R22, CN, NO2, halo- gen, OR22, SR22, NR22R23, OCOR22 and NR22COR23, wherein R22 and R23 are independently from each other and at each occurrence C1 -10- alkyl, cyclopentyl, cyclohexyl or phenyl, or, if L1 or L3 are R3 and R4 together with the C-atoms to which they are attached form a 5 to 7- membered non-aromatic ring system, L2 is a linking moiety A, and R1 and R2 are independently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, C6-14-aryl, 5 to 12 membered heteroaryl, COOR30, CONR30R31, COR30, SO3R30, CN, NO2, halogen, OR30, SR30, NR30R31, OCOR30 or NR30COR31, wherein R30 and R31 are independently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, Ce-i4-aryl or 5 to 12 membered heteroaryl, wherein C1-20-alkyi and C5-8-cycloalkyl can be substituted with one or more substitu- ents Rd at each occurrence selected from the group consisting of phenyl, COOR32, CONR32R33, COR32, SO3R32, CN, NO2, halogen, OR32, SR32, NR32R33, OCOR32 and NR2COR33, wherein C6-14-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent Re at each occurrence selected from the group consisting of C1 -10- alkyl, cyclopentyl, cyclohexyl, COOR32, CONR32R33, COR32, SO3R32, CN, NO2, halo- gen, OR32, SR32, NR32R33, OCOR32 and NR32COR33, wherein R32 and R33 are independently from each other and at each occurrence C1 -10- alkyl, cyclopentyl, cyclohexyl or phenyl, wherein linking moiety A is selected from the group consisting of C1 -10-alkylene, C2-10- alkenylene, C5-8-cycloalkylene, C1-4-alkylene-C5-8-cycloalkylene- C1-4-alkylene, C1-4- alkylene-phenylene-C1-4-alkylene, C2-4-alkenylene-C5-8-cycloalkylene- C2-4-alkenylene and C2-4-alkenylene-phenylene-C2-4-alkenylene, which can be substituted with one or more substitutent Rf at each occurrence selected from the group consisting of C1-20- alkyl, C5-8-cycloalkyl, C6-14-aryl, 5 to 12 membered heteroaryl, COOR40, CONR40R41, COR40, SO3R40, CN, NO2, halogen, OR40, SR40, NR40R41, OCOR40 and NR40COR41, wherein R40 and R41 are independently from each other and at each occurrence H, C1 -10-alkyl, C5-8-cycloalkyl, C6-14-aryl or 5 to 12 membered heteroaryl, wherein linking moiety B is C1-4-alkylene, which can be substituted with one or more C1 -10-alkyl, wherein one or more CH2 groups of C1-4-alkylene can be replaced by C=O, (C=O)O, (C=O)NR60 , SO2-NR60, NR60, NR60R61, O or S, wherein R60 and R61 are independently from each other and at each occurrence C1 -10- alkyl. 10. The composition according to claim 9, wherein R1 and R2 are independently from each other and at each occurrence H, C1-20-alkyl, C5-8-cycloalkyl, L1 and L3 are independently from each other and at each occurrence , and Ar1 and Ar2 are independently from each other and at each occurrence an aromatic moiety, which can be substituted with one or more substituent Ra selected from the group consisting of C1-20-alkyl or C5-8-cycloalkyl. 11. The composition according to claim 10, wherein b and e are respectively 1 or 2. 12. The composition according to claim 11, wherein the crosslinking agent has the following structure: 13. The composition according to claim 1, wherein the crosslinking agent is used in an amount of 0.12 to 4% by weight, preferably in an amount of 0.15 to 3.5% by weight, and more preferably in an amount of 0.15 to 3.2% by weight, based on the total weight of the composition. 14. An organic photodiode, comprising: a first electrode, a second electrode, an active layer disposed between the first electrode and the second electrode, a hole blocking layer disposed between the active layer and the second electrode, and an electron blocking layer disposed between the active layer and the first electrode, wherein the electron blocking layer is made from the composition according to any of claims 1-13. 15. an organic photodiode according to claim 14, wherein the electron blocking layer has a thickness in the range of 70 nm to 300 nm, preferably in the range of 80 nm to 250 nm, and more preferably in the range of 90 nm to 200 nm. |
TECHNICAL FIELD
The present invention relates to a composition used for electron blocking layer of organic photodiode, and also relates to organic photodiode comprising an electron blocking layer formed by such composition.
BACKGROUND ART
Organic photodiode is used in a wide range of applications for being light weight, flexible and easily tunable in its organic molecular characteristics. It compensates for the shortcomings of its inorganic counterpart. Organic photodiodes utilizing p type organic donors blended with n type organic acceptors to form the bulk heterojunction active layer, which enables better photon conversion and detectivity of the devices. However, high dark current level and reliability of organic photodiodes have hindered their use for sophisticated applications.
US8399761B2 discloses an organic photovoltaic device with interfacial layer and method of fabricating same. The interfacial layer comprises 5,5'-bis[(p- trichlorosilylpropylphenyl)phenylamino]-2,2'-bithiophene (PABTSi2) which is crosslinked. The overall performance of the photovoltaic device is improved.
US 2009/0302311A1 discloses polymers which can be used as organic semiconductor in organic devices, such as organic diodes. The polymers used in semiconductor devices or organic photovoltaic devices can lead to high efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability.
WO 2015/004563 discloses crosslinkers which can be used for preparing polymer layer in electronic devices. The crosslinkers can absorb radiation at the same wavelength as that used for the photoresist-layer, so that the preparation process can be conducted in a convenient way.
However, combined use of the polymers and crosslinkers has not been disclosed in the prior art. Moreover, it is desired to provide organic photodiodes which have reduced dark current level. CONTENTS OF THE INVENTION
It is an object of the present invention to provide a composition used for electron blocking layer. Electron blocking layer made from such composition shows excellent effect of reducing dark current level of organic electronic devices. The composition comprises an organic semiconducting polymer and a crosslinking agent, wherein the organic semiconducting polymer and the crosslinking agent can undergo crosslinking reaction under thermal and/or light exposure.
The present invention also provides an organic photodiode, which comprises: a first electrode, a second electrode, an active layer disposed between the first electrode and the second electrode, a hole blocking layer disposed between the active layer and the second electrode, and an electron blocking layer disposed between the active layer and the first electrode, wherein the electron blocking layer is made from the composition according to the present invention.
It has been surprisingly found that by using the composition according to the present invention to form the electron blocking layer, organic electronic device comprising such electron blocking layer, such as organic photodiode, has greatly reduced dark current level. Consequently, an organic photodiode comprising said electron blocking layer is energy-efficient and can lead to longer battery life when being used in mobile devices.
DESCRIPTION OF FIGURES
The present invention will be described with reference to the figures, which are not intended to limit the present invention.
Fig. 1 shows a cross-sectional diagram of layers of an organic photodiode.
MODE OF CARRYING OUT THE INVENTION
Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art to which the invention belongs. In one aspect, the invention provides a composition which comprises an organic semiconducting polymer and a crosslinking agent, wherein the organic semiconducting polymer and the crosslinking agent can undergo crosslinking reaction under thermal and/or light exposure.
Preferably, the organic semiconducting polymer may be selected from the group consisting of thiophene-based conjugated polymer and diketo-pyrrole-pyrrole (DPP)- based conjugated polymer. More preferably, the organic semiconducting polymer comprises repeating units of the formula wherein R 1 and R 2 may be the same or different and are selected from hydrogen, a C 1-25 -alkyl group, an alkenyl group, an alkynyl group, an allyl group, which can be substituted one to three times with C 1-4 -alkyl; or a cycloalkyl group, which can be substituted one to three times with C 1-8 -alkyl; a and b are independently of each other an integral number in the range of 0 to 10, Ar 1 and Ar 2 in each case may be the same or different and independently of each other stand for a group of formula p stands for 0, 1 , 2, 3 or 4;
R 3 in each case may be the same or different and is selected from C 1-25 -alkyl group or C 1-18 -alkoxy; and
R 4 and R 4’ independently from each other stand for hydrogen, C 1-25 -alkyl group or C 1- 18 -alkoxy.
In a preferred embodiment, R 1 and R 2 may be the same or different and are selected from hydrogen, a C 1-25 -alkyl group, an alkenyl group, an alkynyl group, or an allyl group, which can be substituted one to three times with C 1-4 alkyl. More preferably,
R 1 and R 2 may be the same or different and are selected from hydrogen, or a C 1-25 - alkyl group. Most preferably, R 1 and R 2 may be the same or different and stand for a C 5-25 -alkyl group.
In another preferred embodiment, a and b are in the range of 0 to 6, preferably in the range of 1 to 3.
In another preferred embodiment, Ar 1 and Ar 2 in each case may be the same or different and independently of each other stand for a group of formula
In another preferred embodiment, the organic semiconducting polymer may have the following structure: wherein R 1 , R 2 , R 3 and R 4 may be the same or different and are selected from hydrogen, a C 1-25 -alkyl group, an alkenyl group, an alkynyl group, an allyl group, which can be substituted one to three times with C 1-4 -alkyl; or a cycloalkyl group, which can be substituted one to three times with C 1-8 -alkyl;
Ar 1 , Ar 2 , Ar 3 and Ar 4 in each case may be the same or different and independently of each other stand for a group of benzene, substituted benzene, thiophene and substituted thiophene; a, b, c and d are independently of each other an integral number in the range of 0 to 10, preferably in the range of 1 to 5 and more preferably in the range of 1 to 3; and n is a number in the range of 0.05 to 0.95 and m is a number in the range of 0.95 to 0.05, preferably n is a number in the range of 0.1 to 0.9 and m is a number in the range of 0.9 to 0.1, and more preferably n is a number in the range of 0.15 to 0.85 and m is a number in the range of 0.85 to 0.15. In another preferred embodiment, the organic semiconducting polymer has the following structure: wherein n is a number in the range of 0.05 to 0.95 while m is a number in the range of 0.95 to 0.05. Preferably, n is a number in the range of 0.5 to 0.9 while m is a number in the range of 0.5 to 0.1. More preferably, n is a number in the range of 0.7 to 0.85 while m is a number in the range of 0.3 to 0.15.
Preferably, the crosslinking agent may be selected from the group consisting of diazirine, phenyl azide, fluoro-phenyl azide and acyl azide. Many bisazides may be used, such as 1 ,6-diazidohexane (DAZH), ethylene bis(4-azido-2,3,5-trifluoro- 6isopropylbenzoate) (sFPA), 4, 4’-bis(azidomethyl)-1,1 ’-biphenyl (BABP), 1,2-bis((4- (azidomethyl)phenethyl)thio)ethane (TBA-X), ethylene bis(4-azido-2, 3,5,6- tetrafluorobenzoate) (Bis(PFBA)), 3,6-bis(5-(4,4”-bis(3-azidopropyl)-[1,1’:3’,1”- terphenyl)-5’-yl)thiophen-2-yl)-2,5-bis(2-ethylhexyl)-2,5- dihydropyrrolo(3,4-c)pyrrole- 1,4-dione (DPPTPTA), 4-4’-bis(1-azido)undecane)dicyclopenta-(2,1-b:3,4-b’)dit hio- phene-bis(5-fluoro-7-(5’-hexyl-(2,2’-bithiophene)-5-yl)b enzo-(c)(1,2,5)thiadiazole) N3- (CPDT(FBTTh2)2), bis(6-azidohexanoate)silicon phthalocyanine (HxN 3 )2-SiPc), and tris(4-(5’-(3-azidopropyl)-2,2’- bithiophen5-yl)phenyl)amine (TPT-N 3 ). More preferably, the crosslinking agent is of formula wherein (1) a is 0, 1 or 2, b is 1, 2, 3 or 4, c is 0 or 1 , d is 0, 1, 2, 3 or 4, e is 0, 1 or 2, x is 0, 1 or 2, y is 0, 1 or 2, z is 0, 1 or 2, w is 0, 1 or 2, n is 0 or 1,
Ar 1 and Ar 2 are independently from each other and at each occurrence an aromatic or heteroaromatic moiety, which can be substituted with one or more substituent R a selected from the group consisting of C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl, 5 to 12 membered heteroaryl, COOR 10 , CONR 10 R 11 , COR 10 , SO 3 R 10 , CN, NO 2 , halogen,
OR 10 , SR 10 , NR 10 R 11 , OCOR 10 and NR 10 COR 11 , wherein R 10 and R 11 are inde- pendently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6 - 1 4 -aryl or 5 to 12 membered heteroaryl, wherein C 1-20 -alkyl and C 5-8 -cycloalkyl can be substituted with one or more substitu- ents R aa at each occurrence selected from the group consisting of phenyl, COOR 12 , CONR 12 R 13 , COR 12 , SO3R 12 , CN, NO 2 , halogen, OR 12 , SR 12 , NR 11 R 12 , OCOR 12 and NR 12 COR 13 , wherein C6-i4-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R ab at each occurrence selected from the group consist- ing of Ci-10-alkyl, cyclopentyl, cyclohexyl, COOR 12 , CONR 12 R 13 , COR 12 , SO3R 12 , CN, NO 2 , halogen, OR 12 , SR 12 , NR 12 R 13 , OCOR 12 and NR 12 COR 13 , wherein R 12 and R 13 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl, and wherein at least two adjacent Ar 1 , at least two adjacent Ar 2 , and/or Ar 1 and Ar 2 , both connected to L 2 or if c = 0 to each other, can be additionally linked by one or more L a , wherein L a is a linking moiety B,
L 1 and L 3 are independently from each other and at each occurrence or wherein
R 3 and R 4 are independently from each other and at each occurrence H , C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl, 5 to 12 membered heteroaryl, COOR 20 , CONR 20 R 21 , COR 20 , SO 3 R 20 , CN, NO 2 , or halogen, wherein R 20 and R 21 are independently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C6-i4-aryl or 5 to 12 membered heteroaryl, wherein C 1-20 -alkyl and C 5-8 -cycloalkyl can be substituted with one or more substitu- ents R b at each occurrence selected from the group consisting of phenyl,
COOR 22 , CONR 22 R 23 , COR 22 , SO 3 R 22 , CN, NO 2 , halogen, OR 22 , SR 22 , NR 22 R 23 , OCOR 22 and NR 22 COR 23 , wherein C 6-14 -aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R c at each occurrence selected from the group consisting of C 1 -10 - alkyl, cyclopentyl, cyclohexyl, COOR 22 , CONR 22 R 23 , COR 22 , SO 3 R 22 , CN, NO 2 , halo- gen, OR 22 , SR 22 , NR 22 R 23 , OCOR 22 and NR 22 COR 23 , wherein R 22 and R 23 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl, or, if U or L 3 are
R 3 and R 4 together with the C-atoms to which they are attached form a 5 to 7- membered non-aromatic ring system,
L 2 is a linking moiety A, and
R 1 and R 2 are independently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C6-i4-aryl, 5 to 12 membered heteroaryl, COOR 30 , CONR 30 R 31 , COR 30 , SO 3 R 30 , CN, NO 2 , halogen, OR 30 , SR 30 , NR 30 R 31 , OCOR 30 or NR 30 COR 31 , wherein R 30 and R 31 are independently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl or 5 to 12 membered heteroaryl, wherein C 1-20 -alkyl and C 5-8 -cycloalkyl can be substituted with one or more substitu- ents R d at each occurrence selected from the group consisting of phenyl, COOR 32 , CONR 32 R 33 , COR 32 , SO 3 R 32 , CN, NO 2 , halogen, OR 32 , SR 32 , NR 32 R 33 , OCOR 32 and NR 32 COR 33 , wherein C 6-14 -aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R e at each occurrence selected from the group consisting of C 1 -10 - alkyl, cyclopentyl, cyclohexyl, COOR 32 , CONR 32 R 33 , COR 32 , SO 3 R 32 , CN, NO 2 , halo- gen, OR 32 , SR 32 , NR 32 R 33 , OCOR 32 and NR 32 COR 33 , wherein R 32 and R 33 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl. Examples of linking moiety A are C 1 -10 -alkylene, C 2-10 -alkenylene, C 5-8 -cycloalkylene, C 1-4 -alkylene-C 5-8 -cycloalkylene- C 1-4 -alkylene, C 1-4 -alkylene-phenylene- C 1-4 - alkylene, C 2-4 -alkenylene-C 5-8 -cycloalkylene-C 2-4 -alkenylene and C 2-4 -alkenylene- phenylene-C 2-4 -alkenylene, which can be substituted with one or more substitutent R f at each occurrence selected from the group consisting of C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl, 5 to 12 membered heteroaryl, COOR 40 , CONR 40 R 41 , COR 40 , SO 3 R 40 , CN, NO 2 , halogen, OR 40 , SR 40 , NR 40 R 41 , OCOR 40 and NR 40 COR 41 , wherein R 40 and R 41 are independently from each other and at each occurrence H, C 1 -10 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl or 5 to 12 membered heteroaryl, wherein C 1-20 -alkyl and C 5-8 -cycloalkyl can be substituted with one or more substitu- ents R fa at each occurrence selected from the group consisting of phenyl,
COOR 42 , CONR 42 R 43 , COR 42 , SO3R 42 , CN, NO 2 , halogen, OR 42 , SR 42 , NR 42 R 43 , OCOR 42 and NR 42 COR 43 , wherein C 6-14 -aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R fc at each occurrence selected from the group consisting of C 1 -10 - alkyl, cyclopentyl, cyclohexyl, COOR 42 , CONR 42 R 43 , COR 42 , SO3R 42 , CN, NO 2 , halo- gen, OR 42 , SR 42 , NR 42 R 43 , OCOR 42 and NR 42 COR 43 , wherein R 42 and R 43 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl, and wherein one or more CH 2 groups of C 1 -10 -alkylene, C 1-4 -alkylene, C 2-10 -alkenylene, C 2 - 4 -alkenylene and/or C 5-8 -cycloalkylene can be replaced by C=O, ( C=O)O, (C=O)NR 50 , SO 2 -NR 50 , NR 50 , NR 50 R 51 , O or S, wherein R 50 and R 51 are independently from each other and at each occurrence C 1 -10 - alkyl.
Examples of linking moiety B are C 1-4 -alkylene, which can be substituted with one or more C 1 -10 -alkyl, wherein one or more CH 2 groups of C 1-4 -alkylene can be replaced by C=O, (C=O)O, (C=O)NR 60 , SO 2 -NR 60 , NR 60 , NR 60 R 61 , O or S, wherein R 60 and R 61 are independently from each other and at each occurrence C 1 -10 - alkyl.
In preferred embodiment, the crosslinking agent has the following structure: wherein a is 0, 1 or 2, b is 1, 2, 3 or 4, c is 0 or 1 , d is 0, 1, 2, 3 or 4, e is 0, 1 or 2, x is 0, 1 or 2, y is 0, 1 or 2, z is 0, 1 or 2, w is 0, 1 or 2,
Ar 1 and Ar 2 are independently from each other and at each occurrence an aromatic or heteroaromatic moiety, which can be substituted with one or more substituent R a selected from the group consisting of C 1-20 -alkyl, C 5-8 -cycloalkyl, Ce-u-aryl, 5 to 12 membered heteroaryl, COOR 10 , CONR 10 R 11 , COR 10 , SO3R 10 , CN, NO 2 , halogen,
OR 10 , SR 10 , NR 10 R 11 , OCOR 10 and NR 10 COR 11 , wherein R 10 and R 11 are inde- pendently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6 - 14 -aryl or 5 to 12 membered heteroaryl, wherein C 1-20 -alkyl and C 5-8 -cyclolkyl can be substituted with one or more substituents R aa at each occurrence selected from the group consisting of phenyl, COOR 12 , CONR 12 R 13 , COR 12 , SO3R 12 , CN, NO 2 , halogen, OR 12 , SR 12 , NR 11 R 12 , OCOR 12 and NR 12 COR 13 , wherein Ce-u-aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R ab at each occurrence selected from the group consist- ing of C 1 -10 -alkyl , cyclopentyl, cyclohexyl, COOR 12 , CONR 12 R 13 , COR 12 , SO3R 12 , CN, NO 2 , halogen, OR 12 , SR 12 , NR 12 R 13 , OCOR 12 and NR 12 COR 13 , wherein R 12 and R 13 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl, and wherein at least two adjacent Ar 1 , at least two adjacent Ar 2 , and/or Ar 1 and Ar 2 , both connected to L 2 or if c = 0 to each other, can be additionally linked by one or more L a , wherein L a is a linking moiety B,
L 1 and L 3 are independently from each other and at each occurrence wherein R 3 and R 4 are independently from each other and at each occurrence H, C 1- 20 -alkyl, C 5-8 -cycloalkyl, Ce-u-aryl, 5 to 12 membered heteroaryl, COOR 20 , CONR 20 R 21 ,
COR 20 , SO 3 R 20 , CN, NO 2 , or halogen, wherein R 20 and R 21 are independently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl or 5 to 12 membered heteroaryl, wherein C 1-20 - alkyl and C 5-8 -cycloalkyl can be substituted with one or more substituents R b at each occurrence selected from the group consisting of phenyl, COOR 22 , CONR 22 R 23 , COR 22 , SO 3 R 22 , CN, NO 2 , halogen, OR 22 , SR 22 , NR 22 R 23 , OCOR 22 and NR 22 COR 23 , wherein C 6-14 -aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R c at each occurrence selected from the group consisting of C 1 -10 - alkyl, cyclopentyl, cyclohexyl, COOR 22 , CONR 22 R 23 , COR 22 , SO 3 R 22 , CN, NO 2 , halo- gen, OR 22 , SR 22 , NR 22 R 23 , OCOR 22 and NR 22 COR 23 , wherein R 22 and R 23 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl, or, if L 1 or L 3 are
R 3 and R 4 together with the C-atoms to which they are attached form a 5 to 7- membered non-aromatic ring system,
L 2 is a linking moiety A, and
R 1 and R 2 are independently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl, 5 to 12 membered heteroaryl, COOR 30 , CONR 30 R 31 , COR 30 , SO 3 R 30 , CN, NO 2 , halogen, OR 30 , SR 30 , NR 30 R 31 , OCOR 30 or NR 30 COR 31 , wherein R 30 and R 31 are independently from each other and at each occurrence H, C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl or 5 to 12 membered heteroaryl, wherein C 1-20 -alkyl and C 5-8 -cycloalkyl can be substituted with one or more substitu- ents R d at each occurrence selected from the group consisting of phenyl, COOR 32 , CONR 32 R 33 , COR 32 , SO 3 R 32 , CN, NO 2 , halogen, OR 32 , SR 32 , NR 32 R 33 , OCOR 32 and NR 2 COR 33 , wherein C 6-14 -aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R e at each occurrence selected from the group consisting of C 1 -10 - alkyl, cyclopentyl, cyclohexyl, COOR 32 , CONR 32 R 33 , COR 32 , SO3R 32 , CN, NO 2 , halo- gen, OR 32 , SR 32 , NR 32 R 33 , OCOR 32 and NR 32 COR 33 , wherein R 32 and R 33 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl.
Examples of linking moiety A are C 1 -10 -alkylene, C 2-10 -alkenylene, C 5-8 -cycloalkylene, C 1-4 -alkylene-C 5-8 -cycloalkylene- C 1-4 -alkylene, C 1-4 -alkylene-phenylene- C 1-4 - alkylene, C 2-4 -alkenylene-C 5-8 -cycloalkylene-C 2-4 -alkenylene and C 2-4 -alkenylene- phenylene-C 2-4 -alkenylene, which can be substituted with one or more substitutent R f at each occurrence selected from the group consisting of C 1-20 -alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl, 5 to 12 membered heteroaryl, COOR 40 , CONR 40 R 41 , COR 40 , SO 3 R 40 , CN, NO 2 , halogen, OR 40 , SR 40 , NR 40 R 41 , OCOR 40 and NR 40 COR 41 , wherein R 40 and R 41 are independently from each other and at each occurrence H, Ci-io-alkyl, C 5-8 -cycloalkyl, C 6-14 -aryl or 5 to 12 membered heteroaryl, wherein C 1-20 -alkyl and C 5-8 -cycloalkyl can be substituted with one or more substitu- ents R fa at each occurrence selected from the group consisting of phenyl,
COOR 42 , CONR 42 R 43 , COR 42 , SO 3 R 42 , CN, NO 2 , halogen, OR 42 , SR 42 , NR 42 R 43 , OCOR 42 and NR 42 COR 43 , wherein C 6-14 -aryl and 5 to 12 membered heteroaryl can be substituted with one or more substituent R fc at each occurrence selected from the group consisting of C 1 -10 - alkyl, cyclopentyl, cyclohexyl, COOR 42 , CONR 42 R 43 , COR 42 , SO 3 R 42 , CN, NO 2 , halo- gen, OR 42 , SR 42 , NR 42 R 43 , OCOR 42 and NR 42 COR 43 , wherein R 42 and R 43 are independently from each other and at each occurrence C 1 -10 - alkyl, cyclopentyl, cyclohexyl or phenyl, and wherein one or more CH2 groups of Ci-10-alkylene, C 1-4 -alkylene, C 2-10 -alkenylene, C 2- 4 -alkenylene and/or C 5-8 -cycloalkylene can be replaced by C=O, (C=O)O, (C=O)NR 50 , SO2-NR 50 , NR 50 , NR 50 R 51 , O or S, wherein R 50 and R 51 are independently from each other and at each occurrence C 1 -10 - alkyl.
Examples of linking moiety B are C 1-4 -alkylene, which can be substituted with one or more Ci-io-alkyl, wherein one or more CH2 groups of C 1-4 -alkylene can be replaced by C=O, (C=O)O, (C=O)NR 60 , SO2-NR 60 , NR 60 , NR 60 R 61 , O or S, wherein R 60 and R 61 are independently from each other and at each occurrence Ci-io- alkyl.
The crosslinking agent can be used in an amount of 0.12 to 4% by weight, based on the total weight of the composition. Preferably, the crosslinking agent is used in an amount of 0.15 to 3.5% by weight, based on the total weight of the composition. More preferably, the crosslinking agent is used in an amount of 0.15 to 3.2% by weight, based on the total weight of the composition.
The composition may optionally comprise an organic solvent. Suitable organic solvent may be selected from the group consisting of volatile organic solvent, such as toluene, xylene, mesitylene, etc. The composition shows good solvent resistance against solvent commonly used in fabrication of organic electronic device, such as acetone, propylene glycol methyl ether acetate (PGMEA), toluene, xylene, mesitylene, dichlorobenzene and dichloromethane. Thus, it enables using a wide range of solvents for the active layer. Moreover, since the composition is photo-patternable, the electron blocking layer can be fabricated into sophisticated structure through a simple process.
The present invention also provides an organic photodiode, which comprises: a first electrode, a second electrode, an active layer disposed between the first electrode and the second electrode, a hole blocking layer disposed between the active layer and the second electrode, and an electron blocking layer disposed between the active layer and the first electrode, wherein the electron blocking layer is made from the composition as described above.
In one embodiment, the electron blocking layer may have a thickness in the range of 70 nm to 300 nm, preferably in the range of 80 nm to 250 nm, and more preferably in the range of 90 nm to 200 nm.
The above definitions and description concerning the composition also apply to the electron blocking layer.
The electron blocking layer can be fabricated by spin coating, blade coating, inkjet printing, gravure printing, slot-die coating and screen printing or photolithography process, or other suitable coating methods which are known in the art.
The active layer is composed of electron donor material and electron acceptor material, which form bulk heterojunction. Electron donor materials are p-type organic semiconductor materials, including at least one of thiophene-based conjugated polymer and diketo-pyrrole-pyrrole (DPP)-based conjugated polymer. Electron acceptor materials include at least one of C60 and fullerene derivatives.
Preferably, the electron donor material of the active layer is the same as the organic semiconducting polymer of the electron blocking layer, so that the active layer has a HOMO level similar to that of the electron blocking layer, which leads to a reduced energy barrier and thus a higher sensitivity of the photodiode, and also reduced dark current level.
Hole blocking layer may be formed by a material known as having hole blocking effect, such as a material selected from the group consisting of Tris-(8- hydroxyquinoline) aluminum (Alq3), Bis(8-hydroxy-2-methylquinoline)-(4- phenylphenoxy)aluminum (BAIq3), 2,2',2"-(1 ,3,5-Benzinetriyl)-tris(1-phenyl-1-H- benzimidazole) (TPBi), Bathocuproine (BCP), Bathophenanthroline (Bphen), 8- Hydroxyquinolinolato-lithium (Liq), T1O2 and ZnO.
The first electrode may be formed from, for example, ITO, IZO, FTO, ZnO and the like. The second electrode may be formed from, for example, Al, Mg, Li, Al-Li, Mg-ln and the like. The materials for forming the first and second electrodes are known and can be selected by those skilled in the art.
By incorporating an electron blocking layer made from the composition according to the present invention, the organic photodiode may have a dark current level of about 0.1 to 1 nA/cm 2 , similar to inorganic photodiodes.
The present invention will now be described with reference to the following examples, which are not intended to limit the present invention.
Example
Starting materials:
P3000, from BASF, wherein n=0.8, m=0.2 and the polymer has a weight average molecular weight of 50 kDa (measured by GPC against Polystyrene standard in THF).
BCP, from Sigma-Aldrich.
P3HT (Poly(3-hexylthiophene-2,5-diyl)) and PCBM ([6,6]-phenyl-C61-butyric acid methyl ester), from Sigma-Aldrich.
Al, from iTASCO.
Test Methods:
Dark current was determined by Keithley 4200, two channel system in black box.
Preparation of the composition and the organic photodiode:
ITO substrate (first electrode, designed by BASF with active area of 0.09 cm 2 , made by AMG) was cleaned in sonication bath with Dl water, acetone and isopropyl alcohol, and then treated with oxygen plasma to remove residue particles. Electron blocking layer material was prepared by dissolving certain amount of organic semiconducting polymer (according to table 1) and crosslinking agent (according to table 1) in 10 ml xylene. Electron blocking layer material was then coated on the substrate using spin coater at a speed of 900 rpm for 30 sec, and subjected to soft bake at 90 °C for 2 minutes. The electron blocking layer had a thickness of 100 nm, which was subjected to UV curing with intensity of 300 mW/cm 2 at 365nm and thermal annealed at 120 °C for 1 hour to fully crosslinked. Active layer material was prepared by dissolving certain amount of electron donor material (according to table 1) and electron acceptor material (according to table 1) in 10 ml xylene. Active layer material was applied using spin coater at a speed of 400 rpm for 30 sec, followed by soft bake of 90 °C for 2 minutes and thermal annealing at 120 °C for 20 minutes. The active layer had a thickness of 100 nm. Hole blocking layer (BCP) was then applied by spin coating at a speed of 1000 rpm for 30 sec on top of the active layer and the hole blocking layer has a thickness less than 10 nm. The second electrode (Al) was deposited through thermal evaporation and the second electrode had a thickness of 100 nm.
Table 1 shows the measured dark current of examples 1 to 12, which are prepared as described above.
Table 1
From the table, it can be seen that when a composition comprising an organic semiconducting polymer and a crosslinking agent is used in the electronic blocking layer, dark current of the organic photodiode can be reduced. Moreover, when the amount of crosslinking agent is in the range 0.12 to 4% by weight, based on the total weight of the composition, the dark current can be controlled to a very low level. In order to know the effect of the thickness of the electron blocking layer on the dark current of the photodiode, Example 4 was repeated, with the thickness of the electron blocking layer varied by changing the spin coating speed.
Table 2 It is obvious that when the thickness of the electron blocking layer decreases to 50 nm, dark current level increases rapidly. Thus, for achieving better effect of inhibiting dark current, it is preferred to use higher thickness of the electron blocking layer.