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Title:
STRAIGHT AND INVERTED PEROVSKITE SOLAR CELLS CONSISTING OF MEERSCHAUM CONTENTS AS SCAFFOLD LAYER
Document Type and Number:
WIPO Patent Application WO/2019/074460
Kind Code:
A2
Abstract:
Invention: It is a perovskite sensitized solar cells characterized by including the structure at least one of inverted or straight geometry, including a natural material, meerschaum, scaffold. These natural materials have a large active area leading the spreading of light absorber perovskite layer larger area in the cell and thus results more efficient solar cells. Beside, in inverted structure, scaffold layer onto polymer or by mixing with polymer leads better conductivity and thus better efficiency. In addition, the scaffold layer obtained from Sea foam (Meerschaum) adsorb the water molecules and thus prevent the interaction between water and perovskite layer resulting longer lifetime of active perovskite layer. The desiccant feature of Meerschaum adsorb the water before reacting with active perovskite layer leading an increase in stability. Moreover, beside the thermal stability, the thermal isolation feature of Sea foam (Meerschaum) play role in improvement of stability.

Inventors:
KUS MAHMUT (TR)
YENEL ESMA (TR)
Application Number:
PCT/TR2018/050530
Publication Date:
April 18, 2019
Filing Date:
September 27, 2018
Export Citation:
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Assignee:
KUS MAHMUT (TR)
YENEL ESMA (TR)
International Classes:
H01L31/00
Attorney, Agent or Firm:
AKKAS, Ahmet (TR)
Download PDF:
Claims:
CLAIMS

1. A perovskite sensitized solar cells characterized by comprising a structure at least one of inverted or straight geometry, including a meerschaum scaffold onto polymer layer or a mixture of polymer meerschaum mesoporous structure in the cell.

Description:
STRAIGHT AND INVERTED PEROVSKITE SOLAR CELLS CONSISTING OF MEERSCHAUM CONTENTS AS SCAFFOLD LAYER TECHNICAL FIELD

Invention: it is related with fabrication of highly efficient, stable and reproducible perovskite solar cells consisting of a scaffold layer based on meerschaum which is a natural material including silisium and magnesium silicates beside iron, aluminium and chrome oxides and knows as sepiolite, kaoline and bentonite.

PREVIOUS TECHNIQUE

Recently, highly efficient and low cost perovskite sensitized solar cells have been gained great attention among solar cell technologies. In this technology, perovskite (commonly methyl ammonium lead iodide) crystalline structure is used as light absorber. Perovskite layer is constructed on a compact n type layer (such as T102, ZnO) coated on transparent conductive oxide (generally florine doped tin oxide) supporting layer. A hole transport layer (such as spiro-OMETAD, P3HT etc. is coated on perovskite layer to construct heterojunction structure and then a conductive electrode (Au, Ag, etc) is deposited to terminate fabrication of solar cell. The excited electron belonging to light absorbing layer is transferred to n type semiconductor and pass through to transparent conductive layer. The generated hole is transferred to top electrode and thus a cycle is formed.

There are two main structure in perovskite solar cells. The first structure is called to be "Planar perovskite solar cell" due to planar formation of all layers. The second structure consists of a mesoporous layer on compact n layer. Mesoporous layer can be obtained with an n type semiconductor as well as an insulating layer such as AI203. Those types of solar cells are called as "Mesoporous perovskite solar cells". The electrons coming from perovskite layer are transferred via mesoporous structure in case the mesoporous structure is an n type semiconductor. In case an insulating material used as mesoporous layer, electrons flow from perovskite surface to n type compact.

The most important problem of perovskite solar cells is stability and reproducibility. Highly efficient perovskite layer must include big crystals, smooth film surface and good contact between the crystals grains. Randomly formed crystals during perovskite formation lead to dramatic decrease in efficiency. The parameters such as environmental conditions, fabrication technique has a great effect on crystal formation. Researchers introduce new methods for reproducible perovskite layer and the research on this topic is ongoing.

Stability is the other problem. Even if a fine perovskite layer, which means the fabrication of highly efficient solar cell, the stability of solar cell depends on the stability of the crystal forming perovskite layer. Since perovskite crystal is sensitive against to environmental conditions (temperature and moisture etc.), and thus the structure rapidly decomposes, the efficiency of solar cells seriously decreases. Although many methods are introduced to increase the stability of cells, the stability is still main problem of this technology.

DESCRIPTION OF FIGURES

Figure 1. The scheme of Perovskite Solar Cell consisting of a scaffold layer based on sea foam (Meerschaum) structures

Figure 2. SEM image of Meerschaum

Figure 3. SEM image of Meerschaum

Description of layers numbered are given below.

Conductive Electrodes

2 Electron Transport Layers

3 Active Perovskite Layer

4 Scaffold (Meerschaum contents) Layer

5 Conductive Polymer Layer

6 Transparent Back sheet DETAILED DESCRIPTION OF THE INVENTION

The subject to invention perovskite sensitized solar cell comprises, a multiple of conductive electrodes, (1 ), an electron transport layer (2), an active perovskite layer (3), a sea foam (Meerschaum) based scaffold layer (4), a conductive polymer layer (5) and a transparent conductive back sheet layer (6).

Invention describes the fabrication of straight or inverted structure of perovskite solar cells consisting of a meerschaum which is natural materials comprising from mostly silisium and magnesium silicates beside some aluminium, iron and chromium oxides knows as sepiolite, kaoline or bentonite scaffold layer instead of well-known synthetic materials (T1O2 and AI2O3 etc) Sea foam (Meerschaum) whose consistence is described above and will be called as Sea foam (Meerschaum) structures afterwards, are insulating materials and used instead of mesoporous AI203 or polymeric scaffold layers. The main advantage of Sea foam (Meerschaum) is having larger active surface area than mesoporous AI203. According to BET measurements, while AI203 has an average 400 m2/gr active surface area, active area for Sea foam (Meerschaum) reaches up to 900 m2/gr. In this case, the light absorbing perovskite layer can be coated on larger area. Thus more light absorption and more efficiency can be obtained. The fibrous structure as well as porous feature of Sea foam (Meerschaum) lead more light transparency and thus give a transparent feature beside natural native. This feature leads the better exposing perovskite layer to most of photons and prevent the light absorption by scaffold layer which decreases the efficiency of solar cell. Perovskite solar cell based on Sea foam (Meerschaum) scaffold layer give at least 25% better efficiency than well-known mesoporous (T102, AI203 etc) perovskite solar cells. Beside the increase in power conversion efficiency, reproducibility increases as well when Sea foam (Meerschaum) (4) is used as scaffold layer. Obtained mesoporous structure lead the formation of fine crystals at surfaces resulting in 80% reproducible solar cell fabrication. On the other hand, meerschaum improves the efficiency by coating onto conductive polymer or hand by mixing with it. In addition, it increases the stability of layers by adsorbing water molecules thus it prevents the decomposition reactions and leads longer lifetime of solar cells beside the improvement of reproducibility.

Another problem described as stability and lifetime is seriously improved by using Sea foam (Meerschaum) as scaffold layer. The scaffold layer obtained from Sea foam (Meerschaum) adsorb the water molecules and thus prevent the interaction between water and perovskite layer resulting longer lifetime of active perovskite layer. The desiccant feature of Sea foam (Meerschaum) adsorb the water before reacting with active perovskite layer leading an increase in stability. Moreover, beside the thermal stability, the thermal isolation feature of Sea foam (Meerschaum) play role in improvement of stability.