A flexible antimony selenide / perovskite tandem solar cell and its preparation method

Abstract

The present invention provides a flexible antimony selenide / perovskite tandem solar cell, which includes a substrate, a back electrode, an antimony selenide absorption layer, a buffer layer, a window layer, an intermediate composite layer, a hole transport layer, a perovskite absorption layer, an electron transport layer and a conductive electrode, which are arranged in sequence; the material of the intermediate composite layer is selected from one or more of molybdenum oxide, indium tin oxide, zinc oxide, aluminum-doped zinc oxide, tin oxide and C60. Compared with the prior art, the present invention composes a multi-junction solar cell of multiple light absorbers with different band gaps, which can not only broaden the utilization range of the solar spectrum, but also reduce the thermal relaxation loss of photo-generated carriers, thereby improving the photoelectric conversion efficiency of the solar cell.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and particularly relates to a flexible antimony selenide / perovskite tandem solar cell and a preparation method thereof. Background Art

[0002] Solar cells can convert solar energy into electrical energy through photoelectric conversion and have attracted much attention for direct use by people. According to the development of solar cells and the light-absorbing layer materials used, solar cells can be divided into three categories. The first category is silicon-based solar cells, including single-crystalline silicon, polycrystalline silicon solar cells, amorphous silicon thin-film solar cells, and silicon tandem solar cells; the second category is compound solar cells, including copper indium gallium selenide (CIGS), cadmium telluride (CdTe), gallium arsenide (GaAs), and perovskite solar cells; the third category is new solar cells, including dye-sensitized solar cells, organic solar cells, and quantum dot solar cells, etc.

[0003] Among them, perovskite solar cells are solar cells that use perovskite-type organometallic halide semiconductors as light-absorbing materials, belonging to the third generation of solar cells, and are also called new concept solar cells.

[0004] Perovskite solar cells use an organic-inorganic hybrid metal halide with a perovskite crystal structure as the light-absorbing layer. Since 2009, they have attracted much attention due to their simple preparation method, low production cost, and excellent optoelectronic performance. The photoelectric conversion efficiency has rapidly increased from 3.8% to 25.5%, becoming the fastest-developing photovoltaic technology currently and the most promising emerging photovoltaic technology in the world.

[0005] However, currently, the light absorption range of single-junction perovskite materials is relatively narrow and can only absorb photons within a specific range, resulting in its Shockley-Queisser efficiency limit, which restricts the further improvement of its photoelectric conversion efficiency. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a flexible antimony selenide / perovskite tandem solar cell with a high photoelectric conversion efficiency and a preparation method thereof.

[0007] The present invention provides a flexible antimony selenide / perovskite tandem solar cell, including a substrate, a back electrode, an antimony selenide absorption layer, a buffer layer, a window layer, an intermediate composite layer, a hole transport layer, a perovskite absorption layer, an electron transport layer, and a conductive electrode arranged in sequence;

[0008] The substrate is a flexible substrate;

[0009] The material of the intermediate composite layer is selected from one or more of molybdenum oxide, indium tin oxide, zinc oxide, aluminum-doped zinc oxide, tin oxide, and C60.

[0010] Preferably, the thickness of the antimony selenide absorption layer is 100 - 300 nm.

[0011] Preferably, the thickness of the buffer layer is 10 - 60 nm; the material of the buffer layer is selected from one or more of cadmium sulfide, zinc sulfide, and indium sulfide.

[0012] Preferably, the thickness of the window layer is 80 - 1000 nm; the material of the window layer is selected from zinc oxide and / or aluminum-doped zinc oxide.

[0013] Preferably, the thickness of the intermediate composite layer is 10 - 120 nm.

[0014] Preferably, the thickness of the hole transport layer is 10 - 200 nm; the material of the hole transport layer is selected from PTAA, spiro-oMeTAD, PEDOT:PSS, nickel oxide, or CuSCN.

[0015] Preferably, the thickness of the perovskite absorption layer is 100 - 350 nm; the material of the perovskite absorption layer is ABX3; wherein, A is one or more of MA, FA, and PEA; MA is CH3NH3; FA is NH2CHNH2; PEA is C8H9NH3; B is Pb and / or Sn; X is one or more of Cl, Br, and I.

[0016] Preferably, the thickness of the electron transport layer is 10 - 100 nm; the material of the electron transport layer is selected from one or more of tin oxide, C60, titanium oxide, PCBM, zinc oxide, and cadmium sulfide.

[0017] The present invention also provides a method for preparing the above flexible antimony selenide / perovskite tandem solar cell, comprising:

[0018] S1) Depositing a back electrode on a substrate to obtain a substrate with a composite back electrode;

[0019] S2) Evaporating an antimony selenide absorption layer on the substrate with the composite back electrode to obtain a substrate with a composite antimony selenide absorption layer;

[0020] S3) Depositing a buffer layer on the substrate with the composite antimony selenide absorption layer to obtain a substrate with a composite buffer layer;

[0021] S4) Depositing a window layer on the substrate with the composite buffer layer to obtain a substrate with a composite window layer;

[0022] S5) Depositing an intermediate composite layer on the substrate with the composite window layer to obtain a substrate with a composite intermediate composite layer;

[0023] S6) Prepare a hole transport layer on the substrate of the composite intermediate composite layer to obtain a substrate of the composite hole transport layer;

[0024] S7) Prepare a perovskite absorption layer on the substrate of the composite hole transport layer to obtain a substrate of the composite perovskite absorption layer;

[0025] S8) Evaporate an electron transport layer on the substrate of the composite perovskite absorption layer to obtain a substrate of the composite electron transport layer;

[0026] S9) Deposit a conductive electrode on the substrate of the composite electron transport layer to obtain a flexible antimony selenide / perovskite tandem solar cell.

[0027] The present invention provides a flexible antimony selenide / perovskite tandem solar cell, which includes a substrate, a back electrode, an antimony selenide absorption layer, a buffer layer, a window layer, an intermediate composite layer, a hole transport layer, a perovskite absorption layer, an electron transport layer and a conductive electrode arranged in sequence; the material of the intermediate composite layer is selected from one or more of molybdenum oxide, indium tin oxide, zinc oxide, aluminum-doped zinc oxide, tin oxide and C60. Compared with the prior art, the present invention composes a multi-junction solar cell with multiple light absorbers having different bandgaps, which can not only broaden the utilization range of the solar spectrum, but also reduce the thermal relaxation loss of photo-generated carriers, thereby improving the photoelectric conversion efficiency of the solar cell.

[0028] Experiments show that the flexible antimony selenide / perovskite tandem solar cell prepared by the present invention broadens the spectral absorption range of the perovskite cell, and the absorption range is broadened from 350-750 nm to 350-1050 nm; the photoelectric conversion efficiency is improved, and the photoelectric conversion efficiency is increased from 16% to 18.5%. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of the flexible antimony selenide / perovskite tandem solar cell provided by the present invention;

[0030] Figure 2 It is an EQE spectrum of the flexible antimony selenide / perovskite tandem solar cell prepared from Sample 3 of Example 4 of the present invention. Detailed Embodiments

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0032] The present invention provides a flexible antimony selenide / perovskite tandem solar cell, which comprises a substrate, a back electrode, an antimony selenide absorption layer, a buffer layer, a window layer, an intermediate composite layer, a hole transport layer, a perovskite absorption layer, an electron transport layer and a conductive electrode arranged in sequence; the substrate is a flexible substrate; the material of the intermediate composite layer is selected from one or more of molybdenum oxide, indium tin oxide, zinc oxide, aluminum-doped zinc oxide, tin oxide and C60.

[0033] See Figure 1 , Figure 1 is a schematic structural diagram of the flexible antimony selenide / perovskite tandem solar cell provided by the present invention; wherein 1 is the substrate, 2 is the back electrode, 3 is the antimony selenide absorption layer, 4 is the buffer layer, 5 is the window layer, 6 is the intermediate composite layer, 7 is the hole transport layer, 8 is the perovskite absorption layer, 9 is the electron transport layer, and 10 is the conductive electrode.

[0034] Among them, the substrate can be a flexible substrate well-known to those skilled in the art without special limitations. In the present invention, it is preferably a metal foil, more preferably a stainless steel foil; the thickness of the substrate is preferably 0.1 - 0.3 mm.

[0035] A back electrode is arranged on the substrate; the back electrode can be a back electrode well-known to those skilled in the art without special limitations. In the present invention, it is preferably metal molybdenum; the thickness of the back electrode is preferably 600 - 1000 nm; in the embodiments provided by the present invention, the thickness of the back electrode is specifically 600 nm, 700 nm, 800 nm, 900 nm, 910 nm, 920 nm, 950 nm or 1000 nm.

[0036] An antimony selenide absorption layer is arranged on the back electrode; the thickness of the antimony selenide absorption layer is preferably 100 - 300 nm.

[0037] A buffer layer is arranged on the antimony selenide absorption layer; the material of the buffer layer is preferably selected from one or more of cadmium sulfide, zinc sulfide and indium sulfide; the thickness of the buffer layer is preferably 10 - 60 nm, more preferably 20 - 50 nm, and still more preferably 20 - 40 nm; in the embodiments provided by the present invention, the thickness of the buffer layer is specifically 40 nm, 25 nm, 23 nm, 35 nm, 37 nm or 20 nm.

[0038] A window layer is provided on the buffer layer; the material of the window layer is preferably zinc oxide and / or aluminum-doped zinc oxide; the thickness of the window layer is preferably 80-1000 nm, more preferably 100-1000 nm, still more preferably 200-800 nm, and most preferably 400-600 nm; in the present invention, the window layer preferably includes a zinc oxide layer and an aluminum-doped zinc oxide layer; the thickness of the zinc oxide layer is preferably 50-200 nm, more preferably 100-150 nm; the thickness of the aluminum-doped zinc oxide layer is preferably 100-800 nm, more preferably 200-600 nm, still more preferably 400-600 nm, and most preferably 500 nm.

[0039] An intermediate composite layer is provided on the window layer; the material of the intermediate composite layer is preferably one or more of molybdenum oxide, indium tin oxide, zinc oxide, aluminum-doped zinc oxide, tin oxide and C60; the thickness of the intermediate composite layer is preferably 10-120 nm, more preferably 20-100 nm, still more preferably 20-80 nm, and most preferably 30-50 nm.

[0040] A hole transport layer is provided on the intermediate composite layer; the material of the hole transport layer is preferably PTAA, spiro-oMeTAD, PEDOT:PSS, nickel oxide or CuSCN; the thickness of the hole transport layer is preferably 10-200 nm, more preferably 15-150 nm, still more preferably 15-100 nm, still more preferably 15-80 nm, and most preferably 15-40 nm; in the embodiments provided by the present invention, the thickness of the hole transport layer is specifically 10 nm, 15 nm, 25 nm, 30 nm, 28 nm, 18 nm or 40 nm.

[0041] A perovskite absorption layer is provided on the hole transport layer; the material of the perovskite absorption layer is preferably ABX3; wherein, A is one or more of MA, FA and PEA, more preferably MA, FA and PEA; the molar ratio of MA, FA and PEA is preferably (0.5-1.5):(0.5-1.5):(0.5-1.5), more preferably (0.8-1.2):(0.8-1.2):(0.8-1.2), still more preferably 1:1:1; MA is CH3NH3; FA is NH2CHNH2; PEA is C8H9NH3; B is Pb and / or Sn; X is one or more of Cl, Br and I, more preferably Br and I; the molar ratio of Br and I is preferably 1:(4-10); the thickness of the perovskite absorption layer is preferably 100-350 nm, more preferably 100-250 nm, and most preferably 150-250 nm; in the embodiments provided by the present invention, the thickness of the perovskite absorption layer is specifically 150 nm, 200 nm or 250 nm.

[0042] An electron transport layer is provided on the perovskite absorption layer; the material of the electron transport layer is preferably one or more of tin oxide, C60, titanium oxide, PCBM, zinc oxide and cadmium sulfide; the thickness of the electron transport layer is preferably 10 to 100 nm, more preferably 30 to 100 nm, still more preferably 50 to 100 nm, and most preferably 80 to 100 nm.

[0043] A conductive electrode is provided on the electron transport layer; the conductive electrode is preferably one or more of indium tin oxide, zinc oxide and aluminum-doped zinc oxide; the thickness of the conductive electrode is preferably 100 to 1000 nm, more preferably 200 to 800 nm, still more preferably 400 to 600 nm, and most preferably 500 nm.

[0044] The present invention combines light absorbers with different bandgaps to form a multi-junction solar cell, which can not only broaden the utilization range of the solar spectrum, but also reduce the thermal relaxation loss of photo-generated carriers, thereby improving the photoelectric conversion efficiency of the solar cell.

[0045] The present invention also provides a method for preparing the above-mentioned flexible antimony selenide / perovskite tandem solar cell, including: S1) depositing a back electrode on a substrate to obtain a substrate with a composite back electrode; S2) evaporating an antimony selenide absorption layer on the substrate with the composite back electrode to obtain a substrate with a composite antimony selenide absorption layer; S3) depositing a buffer layer on the substrate with the composite antimony selenide absorption layer to obtain a substrate with a composite buffer layer; S4) depositing a window layer on the substrate with the composite buffer layer to obtain a substrate with a composite window layer; S5) depositing an intermediate composite layer on the substrate with the composite window layer to obtain a substrate with a composite intermediate composite layer; S6) preparing a hole transport layer on the substrate with the composite intermediate composite layer to obtain a substrate with a composite hole transport layer; S7) preparing a perovskite absorption layer on the substrate with the composite hole transport layer to obtain a substrate with a composite perovskite absorption layer; S8) evaporating an electron transport layer on the substrate with the composite perovskite absorption layer to obtain a substrate with a composite electron transport layer; S9) depositing a conductive electrode on the substrate with the composite electron transport layer to obtain a flexible antimony selenide / perovskite tandem solar cell.

[0046] Among them, the present invention does not have special restrictions on the sources of all raw materials, and they can be commercially available; the substrate, back electrode, antimony selenide absorption layer, buffer layer, window layer, intermediate composite layer, hole transport layer, perovskite absorption layer, electron transport layer and conductive electrode are the same as those described above and will not be elaborated here.

[0047] In the present invention, it is preferred to pre-treat the substrate first; since the substrate in the present invention is preferably a metal foil, the pre-treatment preferably includes grinding, polishing, and then ultrasonic cleaning with deionized water, absolute ethanol and acetone in sequence, and drying.

[0048] Deposit a back electrode on the preprocessed substrate to obtain a substrate with a composite back electrode; the method of depositing the back electrode can be any method well-known to those skilled in the art without special limitations. In the present invention, magnetron sputtering is preferably used; the parameters during magnetron sputtering are preferably as follows: sputtering power 120W, sputtering pressure 0.4 - 1.2 Pa, sputtering time 15 - 30 min, equipment vacuum degree 2.0×10 -4 Pa, target-substrate distance 50 mm, substrate temperature 50°C - 250°C, Ar flow rate 20 - 80 sccm.

[0049] Evaporate and deposit an antimony selenide absorption layer on the substrate with the composite back electrode to obtain a substrate with a composite antimony selenide absorption layer; the evaporation and deposition method is preferably any method well-known to those skilled in the art without special limitations. In the present invention, vacuum evaporation is preferably used; the evaporation and deposition is preferably carried out under the condition that the vacuum degree is less than 1×10 -4 ; the evaporation and deposition temperature is preferably 300°C - 600°C, more preferably 400°C - 600°C, and still more preferably 500°C; the evaporation rate during evaporation and deposition is preferably 0.5 - 1 Å per second, more preferably 0.6 - 0.9 Å per second, and still more preferably 0.7 - 0.8 Å per second.

[0050] Deposit a buffer layer on the substrate with the composite antimony selenide absorption layer to obtain a substrate with a composite buffer layer; the deposition method of the buffer layer can be any method well-known to those skilled in the art without special limitations. In the present invention, chemical bath deposition is preferably used. The solution used during chemical bath deposition includes metal salts, thiourea and complexing agents; the metal salts are preferably cadmium salts, zinc salts or indium salts; the complexing agent is preferably ammonia water; the volume ratio of the ammonia water to the water in the solution is preferably 1:(100 - 200); the concentration of the metal salts in the solution is preferably 0.2 - 0.7 mol / L; the temperature of chemical bath deposition is preferably 55°C - 90°C; the time of chemical bath deposition is preferably 350 - 500 s.

[0051] Deposit a window layer on the substrate with the composite buffer layer to obtain a substrate with a composite window layer; the deposition method of the window layer can be any method well-known to those skilled in the art without special limitations. In the present invention, magnetron sputtering is preferably used.

[0052] Deposit an intermediate composite layer on the substrate with the composite window layer to obtain a substrate with a composite intermediate composite layer; the method of depositing the intermediate composite layer is vacuum evaporation, and it can be directly obtained by vacuum evaporating the commercially available corresponding materials without special limitations.

[0053] A hole transport layer is compounded on the substrate of the composite intermediate composite layer to obtain a substrate of the composite hole transport layer; the method of compounding the hole transport layer can be a method well-known to those skilled in the art without special limitations. When the hole transport layer is an organic substance, it is preferably prepared by spin coating; when the material of the hole transport layer is nickel oxide, a spray pyrolysis method is preferably adopted, that is, a nickel salt solution is sprayed on the intermediate composite layer and sintered to obtain a substrate of the composite hole transport layer; the nickel salt is preferably nickel nitrate; the concentration of the nickel salt solution is preferably 0.05 - 0.3 mol / L, more preferably 0.1 - 0.3 mol / L, still more preferably 0.2 - 0.3 mol / L, and most preferably 0.25 mol / L; the sintering temperature is preferably 300°C - 450°C, more preferably 350°C - 400°C; the sintering time is preferably 20 - 60 min, more preferably 30 - 40 min.

[0054] A perovskite absorption layer is prepared on the substrate of the composite hole transport layer to obtain a substrate of the composite perovskite absorption layer; in the present invention, the perovskite absorption layer is preferably prepared according to the following steps: when A is MA and / or PEA, first AX and BX2 are mixed in an organic solvent and then sprayed onto the surface of the hole transport layer, and after annealing treatment, a perovskite absorption layer can be obtained; when A further includes FA, after spraying, FAX is vapor deposited on the surface of the sprayed layer, and after annealing treatment, a perovskite absorption layer can be obtained; the annealing treatment temperature is preferably 100°C - 150°C; the annealing treatment time is preferably 10 - 60 min; the temperature of the vapor deposition is preferably 70°C - 90°C, more preferably 80°C; the vapor deposition rate is preferably 0.1 - 0.5 Å per second.

[0055] An electron transport layer is vapor deposited on the substrate of the composite perovskite absorption layer to obtain a substrate of the composite electron transport layer; the method of vapor depositing the electron transport layer can be a method well-known to those skilled in the art without special limitations, and in the present invention, vacuum vapor deposition is preferably used.

[0056] A conductive electrode is deposited on the substrate of the composite electron transport layer to obtain a flexible antimony selenide / perovskite tandem solar cell; the method of depositing the conductive electrode can be a method well-known to those skilled in the art without special limitations, and in the present invention, vacuum vapor deposition or magnetron sputtering is preferably used.

[0057] To further illustrate the present invention, the following provides a detailed description of a flexible antimony selenide / perovskite tandem solar cell and its preparation method in combination with embodiments.

[0058] All reagents used in the following examples are commercially available.

[0059] Example 1

[0060] 1) Select a stainless steel foil (1) with a thickness of 0.3 mm, polish it, and then ultrasonically clean it with deionized water, absolute ethanol, and acetone for 30 min respectively, and then dry it with N2;

[0061] 2) Preparation of the metal back electrode (2): Deposit Mo on the stainless steel foil (1) by magnetron sputtering as the back electrode of the Sb2Se3 battery. The parameters are as follows: sputtering power 120 W, sputtering pressure 0.4 - 1.2 Pa, sputtering time 15 - 30 min, equipment vacuum degree 2.0×10 -4 Pa, target - substrate distance 50 mm, substrate temperature 50 - 250 °C, Ar flow rate 20 - 80 sccm. The thickness of the prepared back electrode is 600 - 1000 nm (see Table 1 for details);

[0062] 3) Preparation of the Sb2Se3 absorption layer (3): Under a vacuum degree less than 1*10 -4 Pa, at 500 °C, use the vacuum evaporation method to evaporate a 300 - nm - thick Sb2Se3 layer at an evaporation rate of 0.8 Å per second

[0063] 4) Preparation of the buffer layer (4): Deposit a 25 - nm - thick CdS buffer layer on the Sb2Se3 absorption layer (3) by chemical bath. The parameters are as follows: The solutes in the precursor solution for CdS chemical bath deposition are: cadmium salt (3CdSO4·8H2O), thiourea (SC(NH2)2), and complexing agent ammonia water (NH3·H2O). The solvent is deionized water. Dissolve the cadmium salt and thiourea in a mixed solution of ammonia water and deionized water with a volume ratio of 1:150 at a molar ratio of 1:2, where the mass - ratio concentration of ammonia water is 35% w / w; the concentration of cadmium salt in the mixed solution is 0.2 mol / L. The deposition temperature is 90 °C, and the reaction time is 375 s;

[0064] 5) Preparation of the window layer (5): First deposit a 100 - nm - thick intrinsic zinc oxide layer on the CdS buffer layer (4) by magnetron sputtering, and then sputter - deposit a 500 - nm - thick aluminum - doped zinc oxide layer;

[0065] 6) Preparation of the intermediate composite layer (6): Prepare a 30 - nm - thick SnO2 layer on the window layer (5) by atomic force deposition;

[0066] 7) Preparation of the hole - transporting layer (7): Use the spray - pyrolysis process to spray a 0.25 - mol . L -1 NiNO3 precursor solution on the intermediate composite layer (6) and sinter it at 350 °C for 30 min to obtain a 15 - nm - thick NiOx hole - transporting layer;

[0067] 8) Preparation of perovskite phase absorption layer (8): First, methylammonium bromide (MABr), lead bromide (PbBr2), and lead iodide (PbI2) were dissolved in N,N-dimethylformamide (DMF) solvent in a molar ratio of 1:1:4, and then sprayed onto the NiOx hole transport layer (7) with a spraying thickness of 150 nm. Then, 1M formamidinium iodide (FAI) was deposited onto the hole transport layer at 80 °C with an evaporation rate of 0.1 Å per second to react with MABr, PbBr2, and PbI2 to form perovskite, and then annealed at 150 °C for 10 min to form a 200 nm perovskite phase absorption layer;

[0068] 9) Preparation of electron transport layer (9): A layer of 80 nm C60 was deposited on the perovskite phase absorption layer (8) by vacuum evaporation to obtain the electron transport layer;

[0069] 10) Preparation of counter electrode (10): A 500 nm layer of indium-doped tin oxide was magnetron sputtered on the electron transport layer (9).

[0070] The conversion efficiency of the solar cell obtained in Example 1 was tested, and the results are shown in Table 1.

[0071] Table 1 Influence of different metal back electrodes on the performance of solar cells

[0072]

[0073] Example 2

[0074] 1) A stainless steel foil (1) with a thickness of 0.3 mm was selected, polished, and then ultrasonically cleaned with deionized water, anhydrous ethanol, and acetone for 30 min respectively, and then dried with N2;

[0075] 2) Preparation of metal back electrode (2): Mo was deposited on the stainless steel foil (1) by magnetron sputtering as the back electrode of the Sb2Se3 battery, and the parameters were as follows: sputtering power 120 W, sputtering pressure 1 Pa, sputtering time 15 min, equipment vacuum 2.0×10 - 4 Pa, target-substrate distance 50 mm, substrate temperature 150 °C, Ar flow rate 40 sccm, and the thickness of the prepared back electrode was 910 nm;

[0076] 3) Preparation of Sb2Se3 absorption layer (3): Under a vacuum of less than 1*10 -4 Pa, at 500 °C, a 300 nm thick Sb2Se3 layer was deposited by vacuum evaporation at an evaporation rate of 0.8 Å per second.

[0077] 4) Preparation of the buffer layer (4): A 25-nm CdS buffer layer was deposited on the Sb2Se3 absorption layer (3) by chemical bath. The parameters are as follows: The solutes in the precursor solution for CdS chemical bath deposition are cadmium salt (3CdSO4·8H2O), thiourea (SC(NH2)2), and complexing agent ammonia water (NH3·H2O). The solvent is deionized water. The cadmium salt and thiourea were dissolved in a mixed solution of ammonia water and deionized water with a volume ratio of 1:100 - 200 at a molar ratio of 1:2, where the mass ratio concentration of ammonia water is 35% w / w. The deposition temperature is 55 - 90 °C, and the reaction time is 350 - 500 s;

[0078] 5) Preparation of the window layer (5): First, a 100-nm intrinsic zinc oxide layer was deposited on the CdS buffer layer (4) by magnetron sputtering, and then a 500-nm aluminum-doped zinc oxide layer was sputtered and deposited;

[0079] 6) Preparation of the intermediate composite layer (6): A 30-nm SnO2 layer was prepared on the window layer (5) by atomic force deposition;

[0080] 7) Preparation of the hole transport layer (7): Using the spray pyrolysis process, a 0.25 mol·L -1 NiNO3 precursor solution was sprayed on the intermediate composite layer (6) and sintered at 350 °C for 30 min to obtain a 15-nm NiOx hole transport layer;

[0081] 8) Preparation of the perovskite phase absorption layer (8): First, methylammonium bromide (MABr), lead bromide (PbBr2), and lead iodide (PbI2) were dissolved in an N-N dimethylformamide (DMF) solvent at a molar ratio of 1:1:4, and it was sprayed onto the NiOx hole transport layer (7) with a spraying thickness of 200 nm. Then, 1M formamidinium iodide (FAI) was deposited onto the hole transport layer at 80 °C with an evaporation rate of 0.1 Å per second to react with MABr, PbBr2, and PbI2 to form perovskite, and then annealed at 150 °C for 10 min to form a 200-nm perovskite phase absorption layer;

[0082] 9) Preparation of the electron transport layer (9): A 80-nm C60 layer was evaporated onto the perovskite phase absorption layer (8) by vacuum evaporation to obtain the electron transport layer;

[0083] 10) Preparation of the counter electrode (10): A 500-nm indium-doped tin oxide or aluminum-doped zinc oxide was magnetron sputtered on the electron transport layer (9).

[0084] Table 2 Influence of different CdS process parameters on the performance of solar cells

[0085]

[0086] Example 3

[0087] 1) Select a stainless-steel foil (1) with a thickness of 0.1 mm, polish it, and then ultrasonically clean it with deionized water, absolute ethanol, and acetone for 30 min respectively, and then dry it with N2;

[0088] 2) Preparation of the metal back electrode (2): Deposit Mo on the stainless-steel foil (1) by magnetron sputtering as the back electrode of the Sb2Se3 battery. The parameters are as follows: sputtering power 120 W, sputtering pressure 1 Pa, sputtering time 15 min, equipment vacuum 2.0×10 - 4 Pa, target-substrate distance 50 mm, substrate temperature 150 °C, Ar flow rate 40 sccm, and the thickness of the prepared back electrode is 910 nm;

[0089] 3) Preparation of the Sb2Se3 absorption layer (3): Under a vacuum of less than 1*10 -4 Pa, at 500 °C, use the vacuum evaporation method to evaporate a 300-nm-thick Sb2Se3 layer at an evaporation rate of 0.8 Å per second.

[0090] 4) Preparation of the buffer layer (4): Deposit a 35-nm CdS buffer layer on the Sb2Se3 absorption layer (3) by chemical bath, where the mass ratio concentration of ammonia water is 35% w / w. The deposition temperature is 70 °C and the reaction time is 420 s;

[0091] 5) Preparation of the window layer (5): First deposit a 100-nm intrinsic zinc oxide layer on the CdS buffer layer (4) by magnetron sputtering, and then sputter-deposit a 500-nm aluminum-doped zinc oxide layer;

[0092] 6) Preparation of the intermediate composite layer (6): Prepare a 30-nm SnO2 layer on the window layer (5) by atomic force deposition;

[0093] 7) Preparation of the hole transport layer (7): Use the spray pyrolysis process to spray the NiNO3 precursor solution with a molar concentration of 0.05 - 0.3 for 10 - 35 circles, and after sintering at 350 - 500 °C for 30 min, obtain a NiO x hole transport layer with a thickness of 10 - 40 nm;

[0094] 8) Preparation of perovskite phase absorption layer (8): First, methylammonium bromide (MABr), lead bromide (PbBr2), and lead iodide (PbI2) are dissolved in N,N-dimethylformamide (DMF) solvent at a molar ratio of 1:1:4. It is sprayed onto the NiOx hole transport layer (7) with a spraying thickness of 200 nm. Then, 1M formamidinium iodide (FAI) is deposited onto the hole transport layer at 80 °C with an evaporation rate of 0.1 Å per second to react with MABr, PbBr2, and PbI2 to form perovskite, and then annealed at 150 °C for 10 min to form a 200-nm perovskite phase absorption layer;

[0095] 9) Preparation of electron transport layer (9): A 30-100-nm C60 layer is deposited on the perovskite phase absorption layer (8) by vacuum evaporation to obtain the electron transport layer;

[0096] 10) Preparation of counter electrode (10): A 500-nm indium tin oxide or aluminum zinc oxide is magnetron sputtered on the electron transport layer (9).

[0097] Table 3 Influence of different hole transport layers on the performance of solar cells

[0098]

[0099] Example 4

[0100] 1) Select a stainless steel foil (1) with a thickness of 0.1 mm, polish it, and then ultrasonically clean it with deionized water, absolute ethanol, and acetone for 30 min respectively, and then dry it with N2;

[0101] 2) Preparation of metal back electrode (2): Mo is deposited on the stainless steel foil (1) by magnetron sputtering as the back electrode of the Sb2Se3 battery. The parameters are as follows: sputtering power 120 W, sputtering pressure 1 Pa, sputtering time 15 min, equipment vacuum 2.0×10 - 4 Pa, target-substrate distance 50 mm, substrate temperature 150 °C, Ar flow rate 40 sccm, and the thickness of the prepared back electrode is 910 nm;

[0102] 3) Preparation of Sb2Se3 absorption layer (3): Under a vacuum less than 1*10 -4 Pa, at 500 °C, a 300-nm-thick Sb2Se3 layer is deposited by vacuum evaporation at an evaporation rate of 0.8 Å per second.

[0103] 4) Preparation of buffer layer (4): A 35-nm CdS buffer layer is deposited on the Sb2Se3 absorption layer (3) by chemical bath, where the mass ratio concentration of ammonia water is 35% w / w. The deposition temperature is 70 °C and the reaction time is 420 s;

[0104] 5) Preparation of the window layer (5): First, a 100-nm intrinsic zinc oxide layer is deposited on the CdS buffer layer (4) by magnetron sputtering, and then a 500-nm aluminum-doped zinc oxide layer is sputter-deposited;

[0105] 6) Preparation of the intermediate composite layer (6): A 30-nm SnO2 layer is prepared on the window layer (5) by atomic force deposition;

[0106] 7) Preparation of the hole transport layer (7): Using the spray pyrolysis process, a 0.3 molar concentration of NiNO3 precursor solution is sprayed 24 times, and after sintering at 350 °C for 30 min, a NiOx hole transport layer with a thickness of 30 nm is obtained;

[0107] 8) Preparation of the perovskite phase absorption layer (8): First, methylammonium bromide (MABr), lead bromide (PbBr2), and lead iodide (PbI2) are dissolved in N,N-dimethylformamide (DMF) solvent in a ratio of 1:1:4, and it is sprayed onto the NiO hole transport layer (7). Then, 1M formamidinium iodide (FAI) is deposited onto the hole transport layer by evaporation at 100 - 250 °C to react with MABr, PbBr2, and PbI2 to form perovskite. After heating at 100 °C for 10 - 60 min, an organic-inorganic hybrid perovskite phase absorption layer with a thickness of 100 - 250 nm is obtained;

[0108] 9) Preparation of the electron transport layer (9): A 80-nm C60 layer is evaporated onto the perovskite phase absorption layer (8) by vacuum evaporation to obtain the electron transport layer;

[0109] 10) Preparation of the counter electrode (10): A 500-nm indium-doped tin oxide or aluminum-doped zinc oxide layer is magnetron sputtered onto the electron transport layer (9).

[0110] Table 4 Influence of different perovskite phase light-absorbing layer preparation processes on the performance of solar cells

[0111]

[0112] The I-V efficiency tests of the cells prepared in Examples 1 - 4 were carried out according to the following method: The I-V curve and the steady-state Jsc were measured by a solar simulator (7SS1503A, simulating AM1.5G sunlight in Beijing, with a light intensity of 100 mW / cm 2, the Keithley Instruments Inc's 2400 digital source meter was used to record data; the Newport Stratford Inc's 91150V silicon solar cell calibrated by NREL was used to calibrate the incident light intensity; the scanning rate was 50 mV / s and the delay time was 0.1 s; the reverse scan was from 1.2 V to 0.05 V, and the forward scan was from 0.05 V to 1.2 V.

[0113] The external quantum efficiency of the solar cell prepared from Sample 3 in Example 4 was detected, and its EQE spectrum was obtained as Figure 2 shown.

Claims

1. A flexible antimony selenide / perovskite tandem solar cell, characterized in that, It includes a substrate, a back electrode, an antimony selenide absorption layer, a buffer layer, a window layer, an intermediate composite layer, a hole transport layer, a perovskite absorption layer, an electron transport layer, and a conductive electrode that are sequentially arranged; The substrate is a flexible substrate; The material of the intermediate composite layer is selected from one or more of molybdenum oxide, indium tin oxide, zinc oxide, aluminum-doped zinc oxide, tin oxide, and C60; The thickness of the antimony selenide absorption layer is 100 - 300 nm; The thickness of the perovskite absorption layer is 100 - 350 nm; the material of the perovskite absorption layer is ABX3; wherein, A is one or more of MA, FA, and PEA; MA is CH3NH3; FA is NH2CHNH2; PEA is C8H9NH3; B is Pb and / or Sn; X is one or more of Cl, Br, and I; The material of the buffer layer is selected from one or more of cadmium sulfide, zinc sulfide, and indium sulfide; The material of the window layer is selected from zinc oxide and / or aluminum-doped zinc oxide; The material of the hole transport layer is selected from PTAA, spiro-oMeTAD, PEDOT:PSS, nickel oxide, or CuSCN; The material of the electron transport layer is selected from one or more of tin oxide, C60, titanium oxide, PCBM, zinc oxide, and cadmium sulfide.

2. The flexible antimony selenide / perovskite tandem solar cell according to claim 1, wherein The thickness of the buffer layer is 10 - 60 nm.

3. The flexible antimony selenide / perovskite tandem solar cell according to claim 1, wherein The thickness of the window layer is 80 - 1000 nm.

4. The flexible antimony selenide / perovskite tandem solar cell according to claim 1, characterized in that, The thickness of the intermediate composite layer is 10 - 120 nm.

5. The flexible antimony selenide / perovskite tandem solar cell according to claim 1, characterized in that, The thickness of the hole transport layer is 10 - 200 nm.

6. The flexible antimony selenide / perovskite tandem solar cell according to claim 1, wherein The thickness of the electron transport layer is 10 - 100 nm.

7. A method for preparing the flexible antimony selenide / perovskite tandem solar cell according to claim 1, characterized in that, It includes: S1) Depositing a back electrode on the substrate to obtain a substrate with a composite back electrode; S2) Evaporating an antimony selenide absorption layer on the substrate with the composite back electrode to obtain a substrate with a composite antimony selenide absorption layer; S3) Depositing a buffer layer on the substrate with the composite antimony selenide absorption layer to obtain a substrate with a composite buffer layer; S4) Depositing a window layer on the substrate with the composite buffer layer to obtain a substrate with a composite window layer; S5) Depositing an intermediate composite layer on the substrate with the composite window layer to obtain a substrate with a composite intermediate composite layer; S6) Preparing a hole transport layer on the substrate with the composite intermediate composite layer to obtain a substrate with a composite hole transport layer; S7) Preparing a perovskite absorption layer on the substrate with the composite hole transport layer to obtain a substrate with a composite perovskite absorption layer; S8) Evaporating an electron transport layer on the substrate with the composite perovskite absorption layer to obtain a substrate with a composite electron transport layer; S9) Depositing a conductive electrode on the substrate with the composite electron transport layer to obtain a flexible antimony selenide / perovskite stacked solar cell.

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