Preparation method of perovskite light absorption layer and perovskite solar cell
By introducing volatile organic compounds during the perovskite thin film preparation process to form a composite thin film and controlling the annealing process, the problems of low photoelectric conversion efficiency and poor stability of perovskite solar cells were solved, and high-efficiency and stable perovskite solar cell performance was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-04-07
AI Technical Summary
Existing perovskite solar cells suffer from low photoelectric conversion efficiency, poor device stability, and severe defects, mainly due to the presence of unreacted PbI2 and pores within the perovskite film, resulting in poor crystal quality and low coverage.
By introducing volatile organic compounds into the DX2 film to form a composite film, and allowing them to volatilize or decompose during the annealing process, a kinetic advantage is provided, enabling the perovskite precursor to diffuse and react uniformly, forming a dense, large-grained perovskite light-absorbing layer.
This improved the photoelectric conversion efficiency and stability of perovskite solar cells, increased the open-circuit voltage, fill factor, and photoelectric conversion efficiency, and enhanced the stability of the device.
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Figure CN121815933A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of solar cells, in particular to a preparation method of a perovskite light-absorbing layer and a perovskite solar cell. BACKGROUND
[0002] As a new photovoltaic technology, perovskite solar cells have attracted extensive attention and application due to their excellent photoelectric conversion efficiency, low raw material cost and simple preparation process. Perovskite thin film is an important component of perovskite solar cells, and the density and defect density of the perovskite thin film directly affect the photoelectric performance of the perovskite solar cell, such as open-circuit voltage (Voc), fill factor (FF) and photoelectric conversion efficiency (PCE). At present, the perovskite thin film is mainly prepared by a two-step method, specifically: first, evaporate an inorganic phase such as a PbI2 thin film, and then deposit an organic phase on the PbI2 thin film to form a perovskite structure through in-situ reaction. However, the two-step method in the prior art has significant limitations. After evaporating the PbI2 thin film, the reaction speed with the FAI (formamidinium iodide) solution is extremely fast and difficult to control. This instantaneous reaction forms a dense perovskite layer on the surface of the PbI2 thin film, hindering the further diffusion and reaction of FAI into the PbI2, resulting in a large amount of unreacted PbI2 and pores in the perovskite thin film. The existence of unreacted PbI2 and pores and defects seriously reduces the crystalline quality and coverage of the perovskite thin film, resulting in poor crystalline quality, low coverage and many defects of the perovskite thin film, which seriously affects the low photoelectric conversion efficiency and poor device stability of the perovskite solar cell. At present, DMSO (dimethyl sulfoxide) vapor treatment is used to treat the PbI2 thin film to form a PbI2-DMSO intermediate phase, thereby slowing down the reaction rate of PbI2 with FAI and promoting uniform nucleation of perovskite. However, this method has limited improvement on the photoelectric conversion efficiency and device stability of the perovskite solar cell. Moreover, the DMSO vapor treatment technology has very high requirements on environmental conditions, including humidity, temperature and treatment time. Any slight deviation will affect the film quality. The residual DMSO will cause adverse defects, affecting the photoelectric performance and stability of the perovskite solar cell. SUMMARY
[0003] The main purpose of the present application is to provide a perovskite light-absorbing layer and a perovskite solar cell to solve the problems of low photoelectric conversion efficiency, poor device stability and serious defects of the perovskite solar cell in the prior art.
[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a preparation method of a perovskite light-absorbing layer is provided, comprising the following steps:
[0005] S1, co-depositing DX2 with a volatile organic compound to form a composite film; or depositing DX2 to form a DX2 film, and then placing the DX2 film in a saturated steam atmosphere of the volatile organic compound, and after gas-phase immersion, a composite film is obtained; wherein D is selected from any one of lead element, tin element, and X is selected from any one of bromine element, iodine element;
[0006] S2, spin coating a solution containing perovskite precursors on the composite film, and then performing annealing treatment to obtain a perovskite light-absorbing layer.
[0007] Further, the volatile organic compound comprises a coordination group; and / or,
[0008] The boiling point of the volatile organic compound is 50-80 DEG C; and / or,
[0009] The perovskite precursor comprises a cation and a halide anion, the cation is selected from any one of formamidinium ion, methylamine ion, cesium ion, and the halide anion is selected from any one of iodine ion, bromine ion.
[0010] Further, the volatile organic compound is selected from at least one of methyl acetate, ethyl acetate, and tetrahydrofuran; and / or,
[0011] The mass ratio of DX2 to the volatile organic compound is 1:(3-12); and / or,
[0012] The mass ratio of DX2 to the perovskite precursor is (2-3):1.
[0013] Further, the mass ratio of DX2 to the perovskite precursor is (2-3):1.
[0014] Further, the time of gas-phase immersion is 10-120s; and / or,
[0015] The temperature of the annealing treatment is 100-150 DEG C, and the time of the annealing treatment is 10-30min.
[0016] Further, the perovskite light-absorbing layer comprises a CDX3 type perovskite material, wherein C is selected from any one of cesium, methylamine, and formamidinium, D is selected from any one of lead element and tin element, and X is selected from any one of bromine element and iodine element.
[0017] The second aspect of the application provides a perovskite solar cell, the perovskite solar cell comprising a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an interface modification layer, an electron transport layer, a transparent conductive layer, and a metal electrode layer which are sequentially stacked;
[0018] The perovskite light-absorbing layer is prepared by the preparation method of the perovskite light-absorbing layer of the first aspect.
[0019] Further, the material of the hole transport layer comprises at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, nickel oxide, [4-(7H-dibenzo[c,g]carbazol-7-yl)butyl) phosphonic acid].
[0020] Further, the material of the interface modification layer comprises at least one of piperazine hydriodide, 1,3-diaminopropane dihydriodide, phenethylammonium iodide, ethylenediamine dihydriodide, and the thickness of the interface modification layer is 10 nm to 20 nm.
[0021] Further, the material of the electron transport layer comprises tin dioxide; and / or,
[0022] The material of the transparent conductive layer comprises at least one of indium tin oxide, indium zinc oxide; and / or,
[0023] The material of the metal electrode layer comprises at least one of Au, Ag, Cu, and Al.
[0024] By in-situ or subsequent introduction of volatile organic matter in the DX2 thin film, the volatilization or decomposition of the volatile organic matter itself can provide kinetic advantages for the diffusion and reaction of the perovskite precursor when subsequently reacting with a solution containing a perovskite precursor, thereby achieving slow, uniform and complete conversion, effectively reducing defects in the perovskite layer, and improving the photoelectric conversion efficiency and stability of the perovskite solar cell device, so that the perovskite solar cell device has higher open-circuit voltage (Voc), fill factor (FF) and photoelectric conversion efficiency (PCE), and better stability. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 Fig. 1 is a structural schematic diagram of a perovskite solar cell according to an embodiment of the present application.
[0026] Legend of reference signs:
[0027] 1 - conductive substrate; 2 - hole transport layer; 3 - perovskite light-absorbing layer; 4 - electron transport layer; 5 - transparent conductive layer; 6 - interface modification layer; 7 - metal electrode layer. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments are not specified by the manufacturer, they are all conventional products that can be purchased on the market.
[0029] As described in the background section of this invention, existing perovskite solar cells suffer from low photoelectric conversion efficiency, poor device stability, and severe defects. To address these problems, in a typical embodiment of this invention, a method for preparing a perovskite light-absorbing layer is provided, comprising the following steps:
[0030] S1, co-deposit DX2 with volatile organic compounds to form a composite film; or, deposit DX2 to form a DX2 film, then place the DX2 film in a saturated vapor atmosphere of volatile organic compounds, and after vapor phase immersion, obtain a composite film; wherein, D is selected from any one of lead and tin, and X is selected from any one of bromine and iodine.
[0031] S2, a solution containing the perovskite precursor is spin-coated onto a composite film, and then annealed to obtain a perovskite light-absorbing layer.
[0032] In step S1, DX2 (D is lead or tin, X is bromine or iodine) is combined with volatile organic compounds (VOCs) through co-deposition or vapor phase immersion to form a composite film. Specifically: the co-deposition method involves simultaneously depositing DX2 and VOCs onto the substrate to form a mixed composite film, which allows VOC molecules to bind uniformly with DX2 molecules, providing a more controllable reaction environment for subsequent perovskite formation. The vapor phase immersion method involves first depositing a DX2 film, then placing the DX2 film in a saturated vapor atmosphere containing VOCs. Through vapor phase immersion, the VOCs are adsorbed and permeate into the surface or pores of the DX2 film, forming a composite film, which avoids the inhomogeneity or residue problems caused by liquid processing.
[0033] In step S2, a solution containing a perovskite precursor is spin-coated onto the composite film, followed by annealing. During the annealing process, volatile organic compounds gradually volatilize or decompose, providing uniform top-down conversion conditions for the growth of the perovskite material. This promotes the reaction between DX2 and the perovskite precursor, which helps in the uniform nucleation and growth of the perovskite, avoids common incomplete conversion problems, reduces defects in the perovskite film, and forms a stable CDX3-type perovskite structure, thereby forming a high-quality perovskite light-absorbing layer.
[0034] Through the above steps, the final perovskite light-absorbing layer has advantages such as density, large grain size, and low defect density. Applying the prepared perovskite light-absorbing layer to perovskite solar cells helps to improve the photoelectric performance and stability of perovskite solar cells, resulting in perovskite solar cell devices with higher open-circuit voltage (Voc), fill factor (FF), and photoelectric conversion efficiency (PCE), as well as better stability.
[0035] In some embodiments, the volatile organic compound (VOC) contains a coordinating group. By selecting a VOC containing a coordinating group, such as a carbonyl group, an amino group, a pyridine ring, etc., the VOC can interact with metal ions (such as lead Pb) in DX2 through its coordinating group. 2+ The formation of weak complexes inhibits or slows down the reaction rate between DX2 and the perovskite precursor, which helps to promote the uniform nucleation and growth of perovskite. At the same time, the presence of ligands can adjust the direction and rate of crystal growth, which helps to form larger and more uniform grains, reduce crystal defects, and thus improve the quality and performance of perovskite films.
[0036] In some embodiments, the boiling point of the volatile organic compound is 50°C to 80°C under normal pressure. The volatile organic compound has a low boiling point and can rapidly volatilize or decompose during subsequent annealing. The released molecules leave behind tiny pores or channels, which help promote the diffusion of perovskite precursor molecules into the interior of the composite film, resulting in a more complete and uniform perovskite transformation.
[0037] In some embodiments, the volatile organic compound is selected from at least one of methyl acetate, ethyl acetate, and tetrahydrofuran. These organic solvents containing carbonyl oxygen atoms have moderate coordination ability and volatility characteristics, and can act as reaction rate regulators. They form complexes with DX2 during the vapor deposition process or the vapor phase immersion process, and then volatilize effectively during the annealing process. This provides favorable conditions for the uniform transformation of the perovskite precursor and the growth of the perovskite crystal, and helps to improve the photoelectric conversion efficiency and stability of perovskite solar cells.
[0038] In some embodiments, the perovskite precursor includes a cation and a halide anion, wherein the cation is selected from any one of formamidinium ion, methylamine ion, and cesium ion, and the halide anion is selected from any one of iodide ion and bromide ion.
[0039] The cation can be formamidinium ion (FA). + ), Methylamine ion (MA + ) or cesium ions (Cs + Halogen anions can be iodide ions (I₂). - ) or bromide ion (Br - This can form different types of perovskite materials, specifically those with a predominantly CDX3 structure. The perovskite light-absorbing layer includes CDX3-type perovskite materials, where C represents cations and D represents lead (Pb). 2+ ) or tin (Sn 2+ The metal ions are represented by C, methylamine, and formamidinium; the metal ions represented by D are represented by lead and tin; and the metal ions represented by X are represented by bromine and iodine. For example, C is selected from any one of cesium, methylamine, and formamidinium; D is selected from any one of lead and tin; and X is selected from any one of bromine and iodine.
[0040] In some embodiments, the mass ratio of DX2 to volatile organic compounds is 1:(3~12); and / or, the mass ratio of DX2 to the perovskite precursor is (2~3):1. By controlling the mass ratio of the above raw materials, it is helpful to promote a denser perovskite light-absorbing layer and reduce defects.
[0041] In some embodiments, the vapor phase immersion time is 10s to 120s. Vapor phase immersion is primarily to ensure sufficient contact between the volatile organic compounds and the DX2 film, allowing organic molecules to penetrate into the film surface or pores and form a stable composite structure. By controlling the immersion time, the penetration depth of the organic molecules can be adjusted, further improving the uniformity of the perovskite light-absorbing layer. Specifically, the vapor phase immersion time can be within a range of 10s, 20s, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, 120s, or any combination thereof.
[0042] In some embodiments, the annealing temperature is 100°C to 150°C, and the annealing time is 10 min to 30 min. Annealing promotes the volatilization or decomposition of organic matter and simultaneously facilitates the chemical reaction between the perovskite precursor and the metal halides on the DX2 film, thereby transforming it into a high-quality perovskite film. By controlling the annealing temperature and time within the above range, it helps to accelerate the reaction rate, promote crystal growth, and remove volatile organic molecules, ensuring the purity of the film. Specifically, the annealing temperature can be a range of 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, or any combination thereof, and the annealing time can be a range of 10 min, 15 min, 20 min, 25 min, 30 min, or any combination thereof.
[0043] A second aspect of the present invention provides a perovskite solar cell, such as Figure 1 As shown, the perovskite solar cell includes a conductive substrate 1, a hole transport layer 2, a perovskite light-absorbing layer 3, an interface modification layer 4, an electron transport layer 5, a transparent conductive layer 6, and a metal electrode layer 7, which are sequentially stacked. The perovskite light-absorbing layer 3 is prepared by the method for preparing perovskite light-absorbing layers in the first aspect. The perovskite light-absorbing layer is a key region for the generation and separation of photogenerated carriers (electrons and holes) in a perovskite solar cell. By controlling the perovskite material and its band gap, the perovskite light-absorbing layer can effectively absorb most of the visible light in the solar spectrum, which helps to further improve the photoelectric conversion efficiency of the perovskite solar cell. Due to the inclusion of the aforementioned high-performance perovskite light-absorbing layer, the perovskite solar cell exhibits excellent photoelectric performance and stability, resulting in higher open-circuit voltage (Voc), fill factor (FF), and photoelectric conversion efficiency (PCE), as well as better stability.
[0044] Specifically, in a perovskite solar cell, a conductive substrate provides electrode contacts to collect holes generated by the perovskite light-absorbing layer and guide them through the subsequent metal electrode layer. The hole transport layer (HTL) transports and collects holes to the electrodes. The perovskite light-absorbing layer (PVK) is primarily responsible for light absorption and charge separation. The electron transport layer (ETL) transports electrons to the electrodes. A transparent conductive layer collects electrons from the perovskite light-absorbing layer and guides them through the subsequent metal electrode layer.
[0045] When sunlight shines on a perovskite solar cell, the energy of the photons is absorbed by the perovskite light-absorbing layer, causing electrons to jump from the valence band to the conduction band, forming electron-hole pairs. Subsequently, holes move towards the conductive substrate with the help of the hole transport layer, while electrons migrate towards the transparent conductive layer through the electron transport layer. Finally, the electrons and holes meet in the external circuit and form an electric current, realizing the process of converting light energy into electrical energy.
[0046] In some embodiments, the hole transport layer has a thickness of 10 nm to 30 nm; and / or, the perovskite light-absorbing layer has a thickness of 500 nm to 600 nm; and / or, the electron transport layer has a thickness of 15 nm to 25 nm; and / or, the transparent conductive layer has a thickness of 10 nm to 30 nm. By controlling the thickness of each layer, it is helpful to further optimize the energy transfer and charge collection efficiency of the perovskite solar cell.
[0047] In some embodiments, the hole transport layer material includes poly(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA), poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS), and nickel oxide (NiO). x At least one of [4-(7H-dibenzocarbazole-7-yl)butyl)phosphonic acid]. By controlling specific hole transport layer materials, holes generated by the perovskite light-absorbing layer can be effectively collected and transported to the conductive substrate, promoting charge transport and light absorption performance, and further promoting efficient charge transport and photoelectric conversion.
[0048] In the specific implementation of this invention, poly(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA) can be sourced from Xi'an Baolai, poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) can be sourced from Xi'an Baolai, and nickel oxide (NiO) can be sourced from Xi'an Baolai. x () can be derived from Xi'an Baolai), [4-(7H-dibenzocarbazole-7-yl)butyl)phosphonic acid] can be derived from Xi'an Baolai.
[0049] In some embodiments, the interface modification layer is made of at least one of piperazine hydroiodide (PDI), 1,3-diaminopropane dihydroiodide (PDAI), phenylethyl ammonium iodide (PEAI), and ethylenediamine dihydroiodide (EDAI2), and the thickness of the interface modification layer is 10 nm to 20 nm. By providing an interface modification layer between the perovskite light-absorbing layer and the electron transport layer, energy level matching between the perovskite light-absorbing layer and the electron transport layer is promoted, and the charge transport capability is enhanced. This further optimizes the charge transport and collection at the interface, which helps to further improve the photoelectric conversion efficiency and stability of perovskite solar cells.
[0050] In some embodiments, the electron transport layer is made of tin dioxide; and / or the transparent conductive layer is made of at least one of indium tin oxide and indium zinc oxide. Controlling the materials of the electron transport layer and the transparent conductive layer helps to promote good charge transport and collection, as well as stable electrode contact.
[0051] When the aforementioned perovskite solar cell is in operation, sunlight first passes through the transparent conductive layer and illuminates the perovskite light-absorbing layer. The perovskite material absorbs photons and generates electron-hole pairs. The generated electrons and holes quickly separate. Electrons move to the electron transport layer and are transferred to the transparent conductive layer, and then to the metal electrode layer, forming the current in the external circuit. Holes, on the other hand, are transferred to the hole transport layer and are transported to the intermediate composite layer and the silicon-based cell.
[0052] In some embodiments, the preparation method of the above-mentioned perovskite solar cell includes the following steps: S1, cleaning the ITO glass surface sequentially with water, detergent, deionized water, acetone, and anhydrous ethanol for 15 minutes each time, followed by ultraviolet ozone (UVO) treatment for 15 minutes; S2, coating the hole transport layer material dispersion (concentration of 0.5 mg / mL to 1 mg / mL) onto the ITO surface using a spin-coating method to form a hole transport layer; S3, co-depositing DX2 with volatile organic compounds to form a composite film; or, depositing DX2 to form a DX2 film, and then placing the DX2 film in a saturated vapor chamber of volatile organic compounds. In a vapor atmosphere, after vapor phase immersion, a composite film is obtained; wherein, D is selected from any one of lead and tin, and X is selected from any one of bromine and iodine; a solution containing a perovskite precursor is spin-coated onto the composite film, and then annealed to obtain a perovskite light-absorbing layer; S4, an interface modification layer material is vapor-deposited onto the surface of the perovskite light-absorbing layer to form an interface modification layer; S5, an electron transport layer is formed on the surface of the perovskite light-absorbing layer by atomic deposition; S6, a transparent conductive layer material is deposited on the surface of the electron transport layer to form a transparent conductive layer; wherein, the deposition can be performed using sputtering PVD deposition method; S7, a metal electrode layer is formed on the surface of the transparent conductive layer by screen printing.
[0053] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.
[0054] Example 1
[0055] The fabrication method of the perovskite solar cell in this embodiment includes the following steps:
[0056] S1, the ITO transparent conductive glass is cleaned sequentially with water, detergent, deionized water, acetone and anhydrous ethanol for 15 minutes each time, followed by ultraviolet ozone treatment for 15 minutes, with a thickness of 15nm.
[0057] S2, a dispersion of [4-(7H-dibenzocarbazole-7-yl)butyl)phosphonic acid] (concentration of 0.5 mg / mL) was spin-coated onto the surface of the intermediate composite layer to form a hole transport layer (thickness of 20 nm).
[0058] S3, PbI2 and tetrahydrofuran at a mass ratio of 1:5 were co-deposited to form a composite film; a solution containing the perovskite precursor was spin-coated onto the composite film, and then annealed at 110℃ for 15 min to obtain a perovskite light-absorbing layer (thickness of 520 nm), with a mass ratio of PbI2 to perovskite precursor of 2.68:1; the temperature of the PbI2 evaporation source was 430℃, the temperature of the tetrahydrofuran evaporation source was 5℃, and the evaporation time was 40 min;
[0059] S4, the interface modification layer material is vapor-deposited onto the surface of the perovskite light-absorbing layer to form an interface modification layer (thickness of 15nm).
[0060] S5, SnO2 electron transport layer material is vapor deposited on the surface of the interface modification layer to form an electron transport layer (thickness of 20nm).
[0061] S6. TCO material is deposited on the surface of the electron transport layer by sputtering PVD to form a transparent conductive layer (thickness of 25nm).
[0062] S7, using screen printing to form an Ag electrode (thickness of 110 nm) on the surface of the transparent conductive layer.
[0063] Example 2
[0064] The difference from Example 1 is that in step S3, PbI2 is deposited to form a PbI2 film, and then the PbI2 film is placed in saturated vapor filled with ethyl acetate and immersed for 60 seconds to form a composite film. Then, a solution containing the perovskite precursor is coated on the composite film and annealed to obtain a perovskite light-absorbing layer (thickness of 600 nm).
[0065] Example 3
[0066] The difference from Example 1 is that in step S3, PbI2 is deposited to form a PbI2 film; the co-deposited PbI2 film is transferred to a special processing chamber, in which tetrahydrofuran (THF) saturated vapor is introduced and the film is treated in this atmosphere for 90 s; then, a solution containing the perovskite precursor is spin-coated onto the composite film and annealed at 110 °C for 15 min to obtain a perovskite light-absorbing layer (thickness of 530 nm).
[0067] Example 4
[0068] The difference from Example 1 is that in step S3, PbI2 and tetrahydrofuran are co-deposited at a mass ratio of 1:10 to form a composite film; a solution containing the perovskite precursor is spin-coated onto the composite film, and then annealed at 110°C for 15 min to obtain a perovskite light-absorbing layer (thickness of 560 nm).
[0069] Example 5
[0070] The difference from Example 1 is that step S4 is omitted, that is, the interface decoration layer is not set.
[0071] Comparative Example 1
[0072] The difference from Example 1 is that in step S3, PbI2 is deposited to form a PbI2 film, and then a solution containing the perovskite precursor is spin-coated onto the PbI2 film, followed by annealing to obtain a perovskite light-absorbing layer (thickness of 530 nm).
[0073] Test methods
[0074] The sample was subjected to AM1.5G, 100mW / cm 2 The JV curve of the battery was tested under illumination, and the following parameters were obtained: open circuit voltage (Voc), fill factor (FF), power conversion efficiency (PCE), and stability under a nitrogen atmosphere at T80, 85℃. The specific test results are shown in Table 1 below.
[0075] Table 1
[0076]
[0077] As shown in Table 1, compared to Comparative Example 1, Examples 1-5, by introducing volatile organic compounds in situ or subsequently into the DX2 thin film, provide a kinetic advantage for the diffusion and reaction of the perovskite precursor during subsequent reactions with a solution containing the perovskite precursor. This effectively reduces defects in the perovskite layer, improves the photoelectric conversion efficiency and stability of the perovskite solar cell device, and results in higher open-circuit voltage (VOC), fill factor (FF), and photoelectric conversion efficiency (PCE), as well as better stability.
[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a perovskite light-absorbing layer, characterized in that, Includes the following steps: S1, co-deposit DX2 with volatile organic compounds to form a composite film; or, deposit DX2 to form a DX2 film, then place the DX2 film in a saturated vapor atmosphere of volatile organic compounds, and after vapor phase immersion, obtain a composite film; wherein, D is selected from any one of lead and tin, and X is selected from any one of bromine and iodine. S2, spin-coating a solution containing the perovskite precursor onto the composite film, followed by annealing, to obtain the perovskite light-absorbing layer.
2. The method for preparing the perovskite light-absorbing layer according to claim 1, characterized in that, The volatile organic compound contains a coordinating group; and / or, The boiling point of the volatile organic compound is 50℃~80℃; and / or, The perovskite precursor comprises a cation and a halide anion, wherein the cation is selected from any one of formamidinium ion, methylamine ion, and cesium ion, and the halide anion is selected from any one of iodide ion and bromide ion.
3. The method for preparing the perovskite light-absorbing layer according to claim 1 or 2, characterized in that, The volatile organic compound is selected from at least one of methyl acetate, ethyl acetate, and tetrahydrofuran; and / or, The mass ratio of DX2 to the volatile organic compound is 1:(3~12); and / or, The mass ratio of DX2 to the perovskite precursor is (2~3):
1.
4. The method for preparing the perovskite light-absorbing layer according to claim 1 or 2, characterized in that, The mass ratio of DX2 to the perovskite precursor is (2~3):
1.
5. The method for preparing the perovskite light-absorbing layer according to claim 1 or 2, characterized in that, The vapor phase immersion time is 10s~120s; and / or, The annealing temperature is 100℃~150℃, and the annealing time is 10min~30min.
6. The method for preparing the perovskite light-absorbing layer according to any one of claims 1 to 5, characterized in that, The perovskite light-absorbing layer comprises a CDX3 type perovskite material, wherein C is selected from any one of cesium, methylamine, and formamidinium, D is selected from any one of lead and tin, and X is selected from any one of bromine and iodine.
7. A perovskite solar cell, characterized in that, The perovskite solar cell comprises a conductive substrate (1), a hole transport layer (2), a perovskite light-absorbing layer (3), an interface modification layer (4), an electron transport layer (5), a transparent conductive layer (6), and a metal electrode layer (7) stacked sequentially. The perovskite light-absorbing layer (3) is prepared by the method for preparing the perovskite light-absorbing layer according to any one of claims 1 to 6.
8. The perovskite solar cell according to claim 7, characterized in that, The hole transport layer (2) is made of at least one of the following: poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine, poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, nickel oxide, and [4-(7H-dibenzocarbazole-7-yl)butyl)phosphonic acid].
9. The perovskite solar cell according to claim 7 or 8, characterized in that, The material of the interface modification layer (4) includes at least one of piperazine hydroiodide, 1,3-diaminopropane dihydroiodide, phenylethyl iodide, and ethylenediamine dihydroiodide, and the thickness of the interface modification layer (4) is 10 nm to 20 nm.
10. The perovskite solar cell according to any one of claims 7 to 9, characterized in that, The material of the electron transport layer (5) includes tin dioxide; and / or, The material of the transparent conductive layer (6) includes at least one of indium tin oxide and indium zinc oxide; and / or, The material of the metal electrode layer (7) includes at least one of Au, Ag, Cu, and Al.