Perovskite solar cell and preparation method thereof

Abstract

The application relates to the technical field of solar cells, in particular to a perovskite solar cell, which is sequentially provided with a transparent conductive substrate layer, a first contact layer, a perovskite light absorption layer, a second contact layer and a conductive electrode layer from bottom to top; the transparent conductive substrate layer comprises a transparent substrate layer and a transparent oxide conductive layer, and a plurality of conductive contact layers are arranged between the first contact layer and the transparent conductive substrate layer; the conductive contact layer is prepared, the conductive electrode is deeply arranged in the first contact layer, the conductivity of the ITO film itself is improved, the conductive contact layer increases the contact area and the extraction speed of the conductive electrode to the photo-generated carriers, the carrier recombination is reduced, and the photoelectric performance of the perovskite solar cell is improved; the conductive contact layer has simple preparation process, high implementability and repeatability, does not affect the surface morphology of the perovskite film, and is beneficial to the preparation of the perovskite solar cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a perovskite solar cell and a preparation method thereof. BACKGROUND

[0002] As a new darling of the photovoltaic industry, the perovskite solar cell has rapidly increased its photoelectric conversion efficiency from 3.8% to 25.7% in the past 13 years. Its low cost, high efficiency and good tolerance to defects have become its distinctive features. More and more researchers believe that the perovskite solar cell has the potential to surpass the crystalline silicon solar cell and the CIGS thin-film solar cell. Therefore, the perovskite material has been ranked as one of the top ten scientific breakthroughs in 2013 by Science.

[0003] At present, the photoelectric conversion efficiency of the perovskite solar cell in most laboratories is less than 22%. Although the photoelectric conversion efficiency of the perovskite solar cell can be increased to more than 23% by means of interface modification, material system optimization and process optimization, the preparation process is complicated and the quality of the thin film is required to be high. For example, the process for treating the perovskite absorption layer and the contact layer by means of interface modification is unstable and has poor repeatability. Therefore, there is currently a lack of a perovskite solar cell efficiency improvement scheme which has low requirements for the quality of the perovskite thin film and high repeatability.

[0004] In the existing technical scheme, the perovskite solar cell is prepared by using a planar structure. Therefore, the thin film has poor quality and there are too many recombination centers. In addition, the ITO substrate has low conductivity, which is not conducive to the transmission of carriers, so that the device exhibits low photoelectric conversion efficiency. SUMMARY

[0005] In order to solve the technical problems mentioned in the background, the purpose of the present application is to provide a perovskite solar cell and a preparation method thereof. The contact layer is prepared by using a local contact method, so as to improve the low efficiency and poor repeatability of the perovskite solar cell.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a perovskite solar cell, the solar cell is sequentially provided with a transparent conductive substrate layer, a first contact layer, a perovskite light absorption layer, a second contact layer and a conductive electrode layer from bottom to top; the transparent conductive substrate layer comprises a transparent substrate layer and a transparent conductive oxide layer; a plurality of conductive contact layers are arranged between the first contact layer and the transparent conductive substrate layer, and the conductive contact layers are embedded in the first contact layer and the transparent conductive substrate layer.

[0007] Compared with the prior art, the present application has the following advantages:

[0008] (1) Through the preparation of the conductive contact layer, the conductive electrode is deeply into the first contact layer, and the conductivity of the ITO thin film itself is also improved, so that the conductive contact layer increases the contact area and also increases the extraction speed of the photo-generated carriers by the conductive electrode, reduces the carrier recombination, and further improves the photoelectric performance of the perovskite solar cell;

[0009] (2) The conductive contact layer has simple and easy-to-implement preparation process, low cost, high repeatability, and does not affect the surface morphology of the perovskite thin film, which is beneficial to the preparation of high-efficiency perovskite solar cells.

[0010] Further, a plurality of the conductive contact layer arrays are provided.

[0011] Further, the transparent substrate layer is at least one of glass, PET, PEN, PEI, and PMMA.

[0012] Further, the material of the transparent conductive oxide layer is at least one of FTO fluorine-doped tin oxide, ITO indium-doped tin oxide, AZO aluminum-doped zinc oxide, ATO aluminum-doped tin oxide, and IGO indium-doped gallium oxide.

[0013] Further, the material of the conductive contact layer is at least one of FTO, ITO, AZO, ATO, IGO, and other transparent conductive oxides or conductive metals such as Ag, Au, Fe, Al, Mg, Ni, Cu, and Na.

[0014] Further, the material of the conductive contact layer can be the same as or different from the material of the transparent conductive oxide layer.

[0015] Further, the deposition method of the conductive contact layer is at least one of mask PVD deposition, screen printing, chemical bath deposition, and sol-gel method.

[0016] Further, the materials of one of the first contact layer and the second contact layer are selected from at least one of N-type semiconductors SnO2, TiO2, and ZnSnO4, and the material of the other is selected from at least one of P-type semiconductors Spiro-oMeTad, NiO, and CuSCN.

[0017] Further, the material of the perovskite layer is a perovskite material with an ABX3 type crystal structure.

[0018] Further, the A is at least one of Cs + , CH(NH2)2 + , CH3NH3 + , and C(NH2)3 + , the B is at least one of Pb 2+ and Sn 2+ , and the X is Br.- - - at least one of FTO, ITO, AZO, ATO, IGO, Ag, Cu, Al, Au.

[0019] Further, the material of the conductive electrode layer is at least one of FTO fluorine-doped tin oxide, ITO indium-doped tin oxide, AZO aluminum-doped zinc oxide, ATO aluminum-doped tin oxide, IGO indium-doped gallium oxide, Ag, Cu, Al, Au. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of the overall cross-sectional structure of an embodiment of the present application;

[0021] Figure 2 is a schematic diagram of the preparation workflow of an embodiment of the present application;

[0022] Figure 3 is a schematic diagram of the top view structure of the conductive contact layer of an embodiment of the present application.

[0023] In the figure: 11, perovskite absorption layer; 12, second contact layer; 13, conductive electrode layer; 14, glass substrate layer; 15, transparent conductive oxide layer; 16, first contact layer; 17, conductive contact layer. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0025] Embodiment:

[0026] Please refer to Figure 1 The present application provides a perovskite solar cell as shown in Figure 1 ​​As shown, a large-area perovskite solar cell, the perovskite solar cell from bottom to top in turn is perovskite solar cell including transparent substrate layer 14, transparent conductive oxide layer 15, conductive contact layer 17, the first contact layer 16, perovskite light absorption layer 11, the second contact layer 12, conductive electrode layer 13, the transparent conductive substrate includes transparent conductive oxide layer 15 and transparent substrate layer 14, the upper surface of the transparent conductive oxide layer 15 is deposited on a thin conductive contact layer 17 according to the pattern, the conductive contact layer 17 is arranged on the surface of the transparent conductive oxide layer 15 in an array, then on the conductive contact layer 17, the first contact layer 16 is deposited at one time, the conductive contact layer 17 is embedded in the transparent oxide layer 15 and the first contact layer 16, so as to ensure the flow of current, and then the first contact layer 16 is deposited on the upper surface in turn perovskite light absorption layer 11, the second contact layer 12 and conductive electrode layer 13.

[0027] In use, the transparent substrate layer 14 is located above and directly contacts sunlight, and the light transmittance needs to be ensured, the transparent substrate layer 1 is at least one of glass, PET, PEN, PEI and PMMA;

[0028] The material of the transparent conductive oxide layer 15 is at least one of FTO fluorine-doped tin oxide, ITO indium-doped tin oxide, AZO aluminum-doped zinc oxide, ATO aluminum-doped tin oxide and IGO indium-doped gallium oxide, and the wavelength of laser etching is at least one of 405 nm, 445 nm, 460 nm, 473 nm, 532 nm, 589 nm, 635 nm, 650 nm, 808 nm, 980 nm and 1064 nm; preferably 532 nm / 1064 nm, which can play the role of etching groove and be used for depositing the conductive contact layer 17, so as to facilitate the embedding of the conductive contact layer 17.

[0029] The conductive contact layer 17 is embedded in the first contact layer 16 and the transparent conductive oxide layer 15, so as to realize conductive work, and the conductive contact layer 17 is arranged in several equal parts, such as Figure 3 As shown, the material can be saved while the working efficiency is improved, and the conductive electrode needs to be able to better extract photo-generated carriers, the material of the conductive contact layer 17 is at least one of transparent conductive oxides such as FTO, ITO, AZO, ATO and IGO, or conductive materials such as Ag, Au, Fe, Al, Mg, Ni, Cu, Na and graphite, the material of the conductive contact layer 17 can be the same as or different from the material of the transparent conductive oxide layer, and the deposition mode of the conductive contact layer 17 is selected from at least one of mask PVD deposition, screen printing, chemical bath deposition and sol-gel method, and mask PVD deposition is preferred, which has better effect.

[0030] The material of the first contact layer 16 and the second contact layer 12 is at least one of N-type semiconductor SnO2, TiO2, ZnSnO4 or P-type semiconductor Spiro-oMeTad, NiO, CuSCN, the N-type semiconductor is used for transmitting electrons, the P-type is used for transmitting holes, the materials of the first contact layer 16 and the second contact layer 12 are not selected to be the same, but can be selected to be N-type semiconductor or P-type semiconductor at will, when the material of one contact layer is selected to be N-type semiconductor, the material of the other contact layer must be selected to be P-type semiconductor.

[0031] The material of the perovskite layer 5 is a perovskite material with ABX3 type crystal structure, the A is at least one of Cs+, CH(NH2)2 + , CH3NH3 + , C(NH2)3 + , the B is at least one of Pb 2+ , Sn 2+ , the X is at least one of Br - , I - , Cl - ; the material of the conductive electrode layer 13 is at least one of FTO fluorine-doped tin oxide, ITO indium-doped tin oxide, AZO aluminum-doped zinc oxide, ATO aluminum-doped tin oxide, IGO indium-doped gallium oxide, Ag, Cu, Al, Au;

[0032] A preparation method of a perovskite solar cell is shown in Figure 2 , including the following steps:

[0033] Step one: etching of the transparent conductive glass 1+2

[0034] The FTO glass with a square resistance of 5Ω / □ and a transmittance of 92% is etched according to the pattern shown in Figure 3 using a laser with a wavelength of 532nm and a power of 10W, to obtain the FTO glass with etching structure, wherein the etching groove depth is 1 / 2 of the thickness of the FTO conductive layer; because the conductivity of the conductive contact layer 17 is higher than that of the transparent conductive oxide, the conductivity of the conductive substrate after recombination is improved by etching the TCO and depositing the conductive contact layer 17 at the etching position, and the contact area is increased due to the existence of the etching groove, which is equivalent to improving the collection ability of the carriers.

[0035] Step two: cleaning of the transparent conductive glass substrate 1+2

[0036] The etched FTO substrate is sequentially ultrasonically cleaned with detergent, deionized water, acetone and ethanol for 20min, then cleaned with high-purity nitrogen blowing and cleaned with an oxygen plasma cleaning machine for 10min to obtain the clean transparent conductive substrate 1+2;

[0037] Step three: preparation of the conductive contact layer 17

[0038] The transparent conductive substrate cleaned above is placed on a mask with a specific pattern, and deposition is performed by thermal evaporation; when the vacuum degree of the chamber drops below 5.0x10-4Pa, evaporation is started, and the current of the heating disc is controlled to be stable at 25 A, so as to deposit a gold electrode with a thickness of 150 nm on the substrate at a rate of 1 A / s. At this time, the conductive contact layer 17 has completely covered the etched groove and is 10 nm higher than the FTO electrode.

[0039] Step four: preparation of the first contact layer 16

[0040] The SnO2 dispersion liquid and deionized water are mixed in a volume ratio of 1:7 to obtain a SnO2 precursor solution, and then a 20-nm-thick SnO2 electron transport layer is deposited on the substrate by Slot-die coating. At this time, the first contact layer 16 has completely covered the conductive contact layer 17, and the thickness of the conductive contact layer 17 is 1 / 2 of the thickness of the first contact layer 16.

[0041] Step five: preparation of the perovskite light absorption layer 5

[0042] CH3NH3I powder and PbI2 with a molar ratio of 1:1.01 are added to a mixed solvent system of DMF / DMSO (volume ratio 3:7), stirred at 70°C for 2 hours, and a perovskite wet film layer is prepared on the SnO2 substrate by Slot-die coating. Annealing and crystallization are performed by heating and drying for 10 min, and finally a black perovskite film with a thickness of 450 nm is obtained.

[0043] Step six: preparation of the second contact layer 6

[0044] A Spiro-oMeTad wet film is prepared on the perovskite light absorption layer 5 substrate by Slot-die coating, and then a hole transport layer with a thickness of 120 nm is obtained by heating and drying for 10 min.

[0045] Step seven: preparation of the conductive electrode layer 13

[0046] A gold electrode is continuously deposited on the second contact layer; when the vacuum degree of the chamber drops below 5.0x10-4Pa, evaporation is started, and the current of the heating disc is controlled to be stable at 25 A, so as to deposit a gold electrode with a thickness of 70 nm on the substrate at a rate of 1 A / s.

[0047] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims with respect to the figures of the patent document.

Claims

1. A perovskite solar cell, characterized in that: The solar cell is provided with, from bottom to top, a transparent conductive substrate layer, a first contact layer, a perovskite light-absorbing layer, a second contact layer, and a conductive electrode layer. The transparent conductive substrate layer includes a transparent substrate layer and a transparent conductive oxide layer. A plurality of conductive contact layers are provided between the first contact layer and the transparent conductive substrate layer. The conductive contact layers are embedded in the first contact layer and the transparent conductive substrate layer. The first contact layer and the second contact layer are made of at least one of the following materials: N-type semiconductor SnO2, TiO2, and ZnSnO4. The other material is made of at least one of the following materials: P-type semiconductor Spiro-oMeTad, NiO, and CuSCN.

2. The perovskite solar cell according to claim 1, characterized in that: Several conductive contact layer arrays are provided.

3. A perovskite solar cell according to claim 1, characterized in that: The transparent substrate layer is at least one of glass, PET, PEN, PEI, and PMMA.

4. A perovskite solar cell according to claim 1, characterized in that: The transparent conductive oxide layer is made of at least one of the following: FTO (fluorine-doped tin oxide), ITO (indium-doped tin oxide), AZO (aluminum-doped zinc oxide), ATO (aluminum-doped tin oxide), and IGO (indium-doped gallium oxide).

5. A perovskite solar cell according to claim 1, characterized in that: The material of the conductive contact layer is at least one of FTO, ITO, AZO, ATO, IGO transparent conductive oxide or conductive metal Ag, Au, Fe, Al, Mg, Ni, Cu, Na.

6. A perovskite solar cell according to claim 5, characterized in that: The material of the conductive contact layer may be the same as or different from the material of the transparent conductive oxide layer.

7. A perovskite solar cell according to claim 5, characterized in that: The conductive contact layer is deposited by at least one of the following methods: mask PVD deposition, screen printing, chemical bath deposition, and sol-gel method.

8. A perovskite solar cell according to claim 1, characterized in that: The perovskite layer is made of perovskite material with an ABX3 crystal structure.

9. A perovskite solar cell according to claim 8, characterized in that: A is Cs + CH(NH2)2 + CH3NH3 + C(NH2)3 + At least one of them, wherein B is Pb 2+ Sn 2+ At least one of them, wherein X is Br - I - Cl - At least one of them.

10. A perovskite solar cell according to claim 1, characterized in that: The material of the conductive electrode layer is at least one of FTO (fluorine-doped tin oxide), ITO (indium-doped tin oxide), AZO (aluminum-doped zinc oxide), ATO (aluminum-doped tin oxide), IGO (indium-doped gallium oxide), Ag, Cu, Al, and Au.

11. A method for fabricating a perovskite solar cell, comprising the following steps: (a) Using a laser to etch a transparent conductive substrate into a specific pattern; (b) The transparent conductive substrate was ultrasonically cleaned for 20 minutes in sequence with detergent, deionized water, acetone and ethanol, then cleaned with high-purity nitrogen and then cleaned with oxygen plasma cleaner for 20 minutes to obtain a clean transparent conductive substrate. (c) The transparent conductive substrate is placed on a mask with a specific pattern, and a conductive contact layer is deposited by thermal evaporation; (d) Deposit a first contact layer on the above-mentioned substrate; (e) Deposit a perovskite light-absorbing layer on the first contact layer; (f) Depositing a second contact layer on a transparent conductive substrate; (g) A conductive electrode layer is deposited on the surface of the second contact layer to obtain a perovskite solar cell.

12. The method for fabricating a perovskite solar cell according to claim 11, characterized in that: In step (a), the depth of the laser etching trench is 10-200 nm, the transparent conductive substrate layer includes a transparent substrate layer and a transparent conductive oxide layer, and the depth of the laser etching trench is 1 / 5-1 of the thickness of the transparent conductive oxide layer.

13. The method for fabricating a perovskite solar cell according to claim 11, characterized in that: The wavelength of the laser is at least one of 405nm, 445nm, 460nm, 473nm, 532nm, 589nm, 635nm, 650nm, 808nm, 980nm, and 1064nm.

14. The method for fabricating a perovskite solar cell according to claim 11, characterized in that: The thickness of the conductive contact layer in step (c) is 10-100 nm, and the thickness of the conductive contact layer is 1 / 5-4 / 5 of the thickness of the first contact layer. The conductivity of the conductive contact layer and the ITO composite layer is lower than that of the transparent oxide.

15. The method for fabricating a perovskite solar cell according to claim 11, characterized in that: The conductive contact layer deposition method in step (c) can be replaced by any one of mask PVD deposition, screen printing, chemical bath deposition, or sol-gel method.

16. The method for fabricating a perovskite solar cell according to claim 11, characterized in that: The thickness of the first contact layer in step (d) is 20-40 nm.

17. The method for fabricating a perovskite solar cell according to claim 11, characterized in that: In step (e), the thickness of the perovskite light-absorbing layer is 350-500 nm.

18. A method for fabricating a perovskite solar cell according to claim 11, characterized in that: The thickness of the second contact layer in step (f) is 80-120 nm.

19. A method for fabricating a perovskite solar cell according to claim 18, characterized in that: In step (f), the deposition method of the second contact layer is one of spinning coating, slot-die coating, doctor blading, spraycoating, and chemical vapor deposition.

20. A method for fabricating a perovskite solar cell according to claim 11, characterized in that: The thickness of the conductive electrode layer in step (g) is 10-100 nm.

21. The method for fabricating a perovskite solar cell according to claim 20, characterized in that: The deposition method of the conductive electrode layer in step (g) is at least one of magnetron sputtering, thermal evaporation, and screen printing.

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