A method based on double-solvent assisted indole butyric acid passivation and its application in trans-inorganic perovskite solar cells

Abstract

This invention provides a method for passivation of inorganic perovskite solar cells based on dual solvent-assisted indolebutyric acid (IBA) and its application in inverted inorganic perovskite solar cells, relating to the field of inorganic perovskite solar cell technology. This IBA material passivates inorganic perovskite solar cells with a PIN structure, primarily targeting the interface on the perovskite layer. The preparation method is as follows: In CsPbI... X Br 3‑X On the surface of an inorganic perovskite thin film, an isopropanol solution of indolebutyric acid (IBA) is spin-coated statically, followed by annealing, and then a methanol solution of IBA is dynamically spin-coated. Finally, the film is annealed at 70–150 °C for 1–10 min. This invention employs a dual-solvent stepwise spin-coating strategy, avoiding problems such as molecular aggregation or excessive grain boundary exposure that are common with single-solvent modification, effectively passivating CsPbIxBr. 3‑X The specific surface defects of the thin film improve humidity stability, promote carrier transport in inorganic perovskite thin films, suppress non-radiative recombination, and improve the open-circuit voltage and photoelectric conversion efficiency of inorganic perovskite solar cells.

Description

Technical Field

[0001] This invention provides a method for preparing inorganic perovskite solar cells based on dual-solvent-assisted indolebutyric acid passivation, belonging to the field of inorganic perovskite solar cell technology. Background Technology

[0002] With the continuous development of society and the economy, global energy demand is constantly increasing. The resource shortages and environmental problems caused by the excessive consumption of traditional fossil fuels are becoming increasingly prominent, making the development of clean and sustainable new energy sources a global consensus. Solar energy, as a renewable energy source with abundant reserves and wide distribution, can be efficiently utilized through photovoltaic technology, becoming an important way to address the energy crisis and environmental challenges. Organic-inorganic hybrid perovskite solar cells, with their advantages of high light absorption coefficient, low manufacturing cost, and rapid improvement in photoelectric conversion efficiency, have become an important representative of current photovoltaic technology. However, traditional hybrid perovskites contain MA + FA + Volatile organic cations are prone to decomposition and phase transition under high temperature, light, and humid conditions, resulting in poor long-term operational stability of the devices and hindering their industrial application.

[0003] Inorganic perovskite absorber layer (CsPbX3, X=Cl) - ,Br - I - Completely eliminating organic components significantly improves intrinsic thermal and optical stability, while also possessing a wide bandgap structure suitable for perovskite-silicon tandem solar cells. This effectively broadens the spectral response range and enhances the overall efficiency of tandem devices, demonstrating significant application value in the field of high-efficiency and stable photovoltaic devices. However, inorganic perovskite films prepared by solution methods exhibit numerous defects on their surface, such as uncoordinated lead ions and halogen vacancies, leading to severe nonradiative recombination losses and significantly reducing the open-circuit voltage and fill factor of the devices. Traditional single-solvent interface modification strategies are prone to passivation molecule aggregation or over-etching, exposing film grain boundaries, exacerbating water and oxygen intrusion, and further reducing device efficiency and stability.

[0004] Therefore, developing an interface modification method that can achieve uniform surface passivation, reduce molecular aggregation, optimize interface energy levels, and improve film stability is of great significance for realizing efficient and stable inorganic perovskite solar cells. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a dual-solvent-assisted indolebutyric acid passivated inorganic perovskite solar cell and its preparation method, thereby solving the problems mentioned in the background art through the following technical solutions.

[0006] Based on the above technical concept, the first objective of this invention is to provide a method for passivation of indolebutyric acid based on dual solvent assistance.

[0007] Specifically, the passivation method based on dual solvent-assisted indolebutyric acid described in this invention involves using dual solvent-assisted indolebutyric acid to passivate the perovskite light-absorbing layer to obtain a passivation layer.

[0008] The second objective of this invention is to provide an inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation.

[0009] Specifically, the inorganic perovskite solar cell based on dual solvent-assisted indolebutyric acid passivation has a PIN structure, including a transparent conductive substrate or an opaque substrate, a hole transport layer, a perovskite light-absorbing layer, a passivation layer, an electron transport layer, a buffer layer, and electrodes stacked sequentially from bottom to top.

[0010] The perovskite light-absorbing layer simultaneously satisfies the following conditions:

[0011] a. The perovskite light-absorbing layer is CsPbI. X Br 3-X Type of inorganic perovskite thin film;

[0012] b. The thickness of the perovskite light-absorbing layer is 400 nm-500 nm; and the passivation layer is obtained by passivating the perovskite light-absorbing layer with indolebutyric acid using a dual solvent-assisted process.

[0013] In some embodiments, the transparent conductive substrate is selected from ITO conductive glass, transparent conductive glass, transparent conductive flexible plastic, and conductive flexible stainless steel, while the opaque conductive substrate is selected from silicon heterojunction bottom cells, tunneling oxide contact silicon bottom cells, back contact silicon bottom cells, and copper indium gallium selenide cells.

[0014] In some embodiments, the material of the hole transport layer is selected from NiO. X One of PTAA, P3CT-N, and SAM.

[0015] In some embodiments, the material of the electron transport layer is selected from PCBM, C 60 One of SnO2.

[0016] In some implementations, the material of the buffer layer is selected from BCP and SnO2.

[0017] In some implementations, the electrodes simultaneously satisfy the following conditions:

[0018] a. The electrode is a metal electrode prepared by thermal evaporation or a screen-printed electrode;

[0019] b. The electrode thickness is 10 nm-1000 nm;

[0020] c. The electrode is a full-area metal electrode or a metal grid line.

[0021] In some alternative embodiments, silver, copper, or gold are preferred as metal electrodes.

[0022] The third objective of this invention is to provide a method for preparing the above-mentioned inorganic perovskite solar cells based on dual-solvent-assisted indolebutyric acid passivation.

[0023] Specifically, a method for fabricating an inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation is disclosed. This inorganic perovskite solar cell has a PIN structure and includes, from bottom to top, a transparent conductive substrate or an opaque substrate, a hole transport layer, a perovskite light-absorbing layer, a passivation layer, an electron transport layer, a buffer layer, and electrodes, stacked sequentially. The perovskite light-absorbing layer is CsPbI. X Br 3-X Type of perovskite thin film;

[0024] The passivation layer is obtained by passivating the perovskite light-absorbing layer with indolebutyric acid using a dual-solvent assisted process. The preparation method is as follows:

[0025] Indolebutyric acid was dissolved in isopropanol at concentrations of 0.1–5 mg / mL and in methanol at concentrations of 0.1–5 mg / mL, and then spin-coated sequentially onto CsPbI. X Br 3-X On the surface of the inorganic perovskite film, indolebutyric acid isopropanol solution was spin-coated at a speed of 3000-5000 r / min for 20-60 s; indolebutyric acid methanol solution was spin-coated at a speed of 3000-5000 r / min for 20-60 s. The spin-coated films were then annealed at a temperature of 70-150 ℃ for 1-10 min to obtain an inorganic perovskite surface passivation layer.

[0026] A fourth objective of this invention is to provide an application of the passivation layer of an inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation prepared by the above method.

[0027] Furthermore, the passivation layer obtained based on dual-solvent-assisted indolebutyric acid passivation is suitable for the following structural devices:

[0028] a. Invert-type inorganic perovskite single-junction solar cell;

[0029] b. Inorganic perovskite / perovskite tandem solar cells;

[0030] c. Inorganic perovskite / crystalline silicon tandem solar cells;

[0031] d. Inorganic perovskite / copper indium gallium selenide tandem solar cells.

[0032] The beneficial effects of this invention are:

[0033] This invention relates to an inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation. The inorganic perovskite light-absorbing layer of the cell is subjected to dual-solvent stepwise passivation modification treatment, which effectively improves the defect states on the surface and at the grain boundaries of the inorganic perovskite film, optimizes the surface morphology and crystal quality of the film, and further improves the photoelectric conversion efficiency of the inorganic perovskite-based solar cell.

[0034] This invention relates to a method for preparing inorganic perovskite solar cells based on dual-solvent-assisted indolebutyric acid passivation. The method is simple and controllable. Indolebutyric acid is dissolved in isopropanol and methanol to prepare a passivation solution, which is then sequentially spin-coated onto the surface of an inorganic perovskite thin film and annealed. The stepwise modification with dual solvents avoids molecular aggregation and excessive etching problems caused by a single solvent, ensuring uniform coverage of perovskite defect sites by passivation molecules. This effectively coordinates and passivates uncoordinated lead ions and halogen vacancies, optimizes interface energy level matching, reduces non-radiative recombination losses, and improves carrier transport characteristics, thereby significantly enhancing the open-circuit voltage, fill factor, and long-term operational stability of the inorganic perovskite-based solar cell. Attached Figure Description

[0035] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0036] Figure 1 The diagram shows the layer structure of the inorganic perovskite solar cell as illustrated in Examples 1-3.

[0037] Figure 2 This is a schematic diagram of the optimized preparation method of inorganic perovskite solar cells according to the present invention.

[0038] Figure 3 This invention relates to a method for preparing the passivation layer;

[0039] Figure 4 The current-voltage characteristic curves of trans-inorganic perovskite solar cells passivated by indolebutyric acid isopropanol solution and indolebutyric acid methanol solution with a concentration of 2 mg / mL are shown in the comparative embodiments of the present invention.

[0040] Figure 5 The current-voltage characteristic curves of the inverse inorganic perovskite solar cell based on the comparative embodiment of the present invention without the introduction of the dual solvent passivation strategy are shown. Detailed Implementation

[0041] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0042] The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. Unless otherwise stated, all reagents used in the following examples are commercially available or synthesized using conventional methods and are ready for direct use without further processing, as are the instruments used in the examples. All technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0043] In recent years, perovskite solar cells have developed rapidly. Traditional organic-inorganic hybrid solar cells, limited by their organic components, while achieving high PCE, suffer from poor light and thermal stability, hindering long-term application. Inorganic perovskite (CsPbX3, X=Cl)... - ,Br - I - Due to its advantages such as good heat resistance, low cost and adjustable band gap, it has attracted much attention from those skilled in the art and is widely used in the preparation of new thin-film solar cells.

[0044] In existing technologies, inorganic perovskite thin films prepared by solution methods exhibit numerous defects on their surfaces, such as uncoordinated lead ions and halogen vacancies, leading to severe nonradiative recombination losses and significantly reducing the open-circuit voltage and fill factor of the devices. However, traditional single-solvent interface modification strategies are prone to passivation molecule aggregation or over-etching, exposing the film grain boundaries, exacerbating water and oxygen intrusion, and further reducing device efficiency and stability.

[0045] CsPbI X Br 3-X It is an ideal top cell material for crystalline silicon tandem solar cells. This application uses CsPbI as the top cell material. X Br 3-X Based on inorganic perovskites, this study addresses the aforementioned issues and aims to provide a passivated inorganic perovskite solar cell and its fabrication method.

[0046] The present invention provides an inorganic perovskite solar cell based on dual solvent-assisted indolebutyric acid passivation, which is a PIN structure and includes, from bottom to top, a transparent conductive substrate or an opaque substrate 1, a hole transport layer 2, a perovskite light-absorbing layer 3, a passivation layer 4, an electron transport layer 5, a buffer layer 6, and an electrode 7 stacked sequentially.

[0047] The perovskite light-absorbing layer 3 simultaneously satisfies the following conditions:

[0048] a. The perovskite light-absorbing layer 3 is CsPbI. X Br 3-X Type of inorganic perovskite thin film;

[0049] b. The thickness of the perovskite light-absorbing layer 3 is 400 nm-500 nm; and the passivation layer 4 is obtained by passivating the perovskite light-absorbing layer 3 with indolebutyric acid using a dual solvent-assisted process.

[0050] According to some embodiments, the transparent conductive substrate 1 is selected from ITO conductive glass, transparent conductive glass, transparent conductive flexible plastic, and conductive flexible stainless steel, while the opaque conductive substrate 1 is selected from silicon heterojunction bottom cell, tunnel oxide contact silicon bottom cell, back contact silicon bottom cell, and copper indium gallium selenide cell.

[0051] According to some embodiments, the material of the hole transport layer 2 is selected from NiO. X One of PTAA, P3CT-N, and SAM.

[0052] According to some embodiments, the material of the electron transport layer 5 is selected from PCBM, C 60 One of SnO2.

[0053] According to some embodiments, the material of the buffer layer 6 is selected from BCP and SnO2.

[0054] According to some embodiments, electrode 7 simultaneously satisfies the following conditions:

[0055] a. The electrode 7 is a metal electrode prepared by thermal evaporation or a screen-printed electrode;

[0056] b. The thickness of the electrode 7 is 10 nm to 1000 nm;

[0057] c. The electrode 7 is a full-area metal electrode or a metal grid line.

[0058] In some alternative embodiments, electrode 7 is preferably made of silver, copper, or gold as a metal electrode.

[0059] An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation, the preparation method of which includes:

[0060] S1. Select a clean ITO conductive glass / transparent conductive glass / transparent conductive flexible plastic / conductive flexible stainless steel / silicon heterojunction bottom cell / tunnel oxide contact silicon bottom cell / back contact silicon bottom cell / copper indium gallium selenide cell as the conductive substrate 1.

[0061] S2. A hole transport layer 2 is prepared on one side surface of the conductive substrate 1;

[0062] S3. In a nitrogen atmosphere, a perovskite light-absorbing layer 3 is prepared by spin-coating on the hole transport layer 2.

[0063] S4. Passivation layer 4 is prepared by spin-coating indolebutyric acid isopropanol solution and indolebutyric acid methanol solution onto perovskite light-absorbing layer 3.

[0064] S5. Spin-coating an electron transport layer 5 onto the passivated perovskite light-absorbing layer 3, i.e., the passivation layer 4.

[0065] S6. Spin-coating a buffer layer 6 onto the electron transport layer 5;

[0066] S7, Electrode 7 is formed by depositing metal on buffer layer 6.

[0067] In some embodiments, the method for preparing the passivation layer 4 specifically includes:

[0068] S41. Weigh a certain amount of indolebutyric acid and dissolve it in isopropanol and methanol respectively to obtain an isopropanol solution of indolebutyric acid with a concentration of 0.1 mg / mL-5 mg / mL and a methanol solution of indolebutyric acid with a concentration of 0.1 mg / mL-5 mg / mL, for later use;

[0069] S42. Using a static spin-coating method, CsPbI is coated with a specific concentration of indolebutyric acid isopropanol solution. x Br 3-x The inorganic perovskite film of the type was passivated and annealed; then, CsPbI was coated with indolebutyric acid methanol solution using a dynamic spin-coating method. x Br 3-x The inorganic perovskite film of the type was passivated to obtain the spin-coated inorganic perovskite film;

[0070] S43. Anneal the spin-coated inorganic perovskite film to obtain passivation layer 4.

[0071] According to some implementation methods, in static spin coating operation, the spin coating speed is 3000-5000 r / min and the spin coating time is 20-60 s; in dynamic spin coating operation, the spin coating speed is 3000-5000 r / min and the spin coating time is 20-60 s.

[0072] According to some implementation methods, in the annealing process, the annealing temperature is 70-150 ℃ and the annealing time is 1 min-10 min.

[0073] Example 1

[0074] This embodiment describes the fabrication of an inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation, such as... Figure 2 and Figure 3 As shown, the preparation method includes:

[0075] S1. Use detergent, deionized water and isopropanol to ultrasonically clean the ITO conductive glass for 10-30 minutes each in sequence, and use it as transparent conductive substrate 1 for later use.

[0076] S2. Dry the cleaned transparent conductive substrate 1 with nitrogen gas and treat it with ozone for 10-30 minutes; spin-coat NiO on one side of the transparent conductive substrate 1. X The solution, NiO is adjusted by controlling the spin coating speed. X The thickness of the solution film was determined, and then it was annealed on a hot plate at 100-150 °C for 10-30 minutes to prepare hole transport layer 2. This process was carried out in air.

[0077] S3, CsPbI X Br 3-X Perovskite was dissolved in a 1:1 volume ratio of DMF and DMSO to prepare a 1.0 M CsPbI solution. X Br 3-X Perovskite precursor solution, ready for use; using a one-step method, in a nitrogen-filled glove box, spin CsPbI on hole transport layer 2. x Br 3-x Perovskite solution was used to prepare perovskite light-absorbing layer 3. The spin coating speed was 1000-3000 r / min and the spin coating time was 100-150 s. Then, the spin-coated material was placed on a hot plate at 170 ℃-190 ℃ and annealed for 1 min-10 min to obtain an inorganic perovskite film with a thickness of about 400 nm-500 nm.

[0078] S4. Dissolve indolebutyric acid in isopropanol and methanol respectively to obtain an indolebutyric acid isopropanol solution with a concentration of 1 mg / mL and an indolebutyric acid methanol solution with a concentration of 1 mg / mL, and set aside. First, spin-coat the indolebutyric acid isopropanol solution onto the perovskite light-absorbing layer 3 at a speed of 3000-5000 r / min using a static solution spin-coating method, anneal it, and then spin-coat the indolebutyric acid methanol solution onto the perovskite light-absorbing layer 3 at a speed of 3000-5000 r / min using a dynamic solution spin-coating method to prepare the passivation layer 4. The spin-coating time is 20-60 s. Then, place it on a hot plate at 70-150 ℃ and anneal for 1-10 min.

[0079] S5. Dissolve PCBM in chlorobenzene to prepare a PCBM solution with a concentration of 10-30 mg / mL for later use; spin-coat the PCBM solution onto the passivated perovskite light-absorbing layer 3, i.e., the passivation layer 4, to prepare the electron transport layer 5. The spin-coating speed of the PCBM solution is 1000-3000 r / min, and the spin-coating time is 20-60 s.

[0080] S6. Dissolve BCP in isopropanol to prepare a BCP solution with a concentration of 0.1-1 mg / mL for later use; spin-coat the buffer layer 6 onto the electron transport layer 5. The spin-coating speed of the BCP solution is 3000-5000 r / min, and the spin-coating time is 20-60 s.

[0081] S7. Using a thermal evaporation process, metallic silver is evaporated and deposited on the buffer layer 6 to form an electrode 7 with a thickness of 10-1000 nm.

[0082] Example 2

[0083] This embodiment prepares an optimized inorganic perovskite solar cell using 4-methoxyphenyl phosphate. The preparation method is basically the same as in Example 1, except that:

[0084] S4. Dissolve indolebutyric acid in isopropanol and methanol respectively to obtain an indolebutyric acid isopropanol solution with a concentration of 2 mg / mL and an indolebutyric acid methanol solution with a concentration of 1 mg / mL, and set aside. First, spin-coat the indolebutyric acid isopropanol solution onto the perovskite light-absorbing layer 3 at a speed of 3000-5000 r / min using a static solution spin-coating method, and anneal it. Then, spin-coat the indolebutyric acid methanol solution onto the perovskite light-absorbing layer 4 using a dynamic solution spin-coating method at a speed of 3000-5000 r / min, and prepare the passivation layer 4. The spin-coating time is 20-60 s. Then, place it on a hot plate at 70-150 ℃ and anneal for 1-10 min.

[0085] The structure of the prepared inorganic perovskite solar cell is as follows: Figure 1 As shown; its performance was tested at AM1.5, 100 mW / cm². 2 Under standard light intensity irradiation, the open-circuit voltage of the unoptimized solar cell prepared in this comparative example is 1.25 V, and the short-circuit current density is 19.34 mA / cm². 2 The fill factor is 84.08%, such as Figure 4 As shown, the efficiency is 20.97%.

[0086] Example 3

[0087] This embodiment prepares an optimized inorganic perovskite solar cell using 4-methoxyphenyl phosphate. The preparation method is basically the same as in Example 1, except that:

[0088] S4. Dissolve indolebutyric acid in isopropanol and methanol respectively to obtain an indolebutyric acid isopropanol solution with a concentration of 3 mg / mL and an indolebutyric acid methanol solution with a concentration of 1 mg / mL, and set aside. First, spin-coat the indolebutyric acid isopropanol solution onto the perovskite light-absorbing layer 3 at a speed of 3000-5000 r / min using a static solution spin-coating method, and anneal it. Then, spin-coat the indolebutyric acid methanol solution onto the perovskite light-absorbing layer 4 using a dynamic solution spin-coating method at a speed of 3000-5000 r / min, and prepare the passivation layer 4. The spin-coating time is 20-60 s. Then, place it on a hot plate at 70-150 ℃ and anneal for 1-10 min.

[0089] Comparative Example 1

[0090] To further compare the technical solution of the present invention and its beneficial effects, an unoptimized inorganic perovskite solar cell was prepared. The preparation method was roughly the same as in Example 1, except that the step of adding indolebutyric acid was omitted in this comparative example.

[0091] The structure of the prepared inorganic perovskite solar cell is as follows: Figure 1 As shown; its performance was tested at AM1.5, 100 mW / cm². 2 Under standard light intensity irradiation, the open-circuit voltage of the unoptimized solar cell prepared in this comparative example is 1.16 V, and the short-circuit current density is 19.32 mA / cm². 2 The fill factor is 80.86%, such as Figure 5 As shown, the efficiency is 18.42%.

[0092] Comparative Example 2

[0093] To further compare the technical solution of the present invention and its beneficial effects, an unoptimized inorganic perovskite solar cell was prepared. The preparation method was roughly the same as in Example 1, except that the dual solvent modification step was omitted in this comparative example.

[0094] The structure of the prepared inorganic perovskite solar cell is as follows: Figure 1 As shown; when its performance was tested, its carrier lifetime decreased to 39.52 ns.

[0095] Further analysis of the inorganic perovskite solar cells prepared in Examples 1–3 revealed that, firstly, with the indolebutyric acid dual solvent system affecting CsPbI... 2.85 Br 0.15With the gradual optimization of the thin film surface modification effect, the open-circuit voltage of inorganic perovskite solar cells showed a gradual upward trend. This is presumably due to the strong coordination between the carboxyl groups in the indolebutyric acid molecule and the uncoordinated lead ions on the perovskite surface, while the hydrophobic molecular framework effectively blocked water intrusion, achieving efficient defect passivation and improved interface stability. Furthermore, with the improvement of the dual-solvent stepwise modification process, the short-circuit current density and fill factor of the device were significantly improved. This is attributed to the effective improvement of the thin film crystal quality, reduction of grain boundary exposure, and optimization of surface morphology and interface energy level matching by the indolebutyric acid dual-solvent strategy. These performance improvements reached their peak under the optimal concentration of 2 mg / mL (IPA) + 1 mg / mL (MeOH) methanol. When the passivator concentration was further increased, although it was still superior to the unpassivated control device, excessive molecules tended to aggregate on the thin film surface, hindering carrier transport and negatively impacting the short-circuit current density, leading to a decline in the overall device performance. Therefore, 2 mg / mL (IPA) + 1 mg / mL (MeOH) was determined to be the optimal passivation concentration, which can enable inorganic perovskite solar cells to achieve the best photoelectric performance.

[0096] The foregoing description is a detailed explanation of the preferred embodiments, basic principles, and beneficial effects of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. Without departing from the spirit or essential characteristics of the present invention, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. All variations falling within the meaning and scope of the equivalent elements of the claims are included within the present invention. Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation, characterized in that, The material includes a perovskite light-absorbing layer and a passivation layer obtained by a dual-solvent-assisted indolebutyric acid passivation method. The dual-solvent-assisted indolebutyric acid passivation method involves using dual solvents to assist indolebutyric acid in passivating the perovskite light-absorbing layer to obtain the passivation layer.

2. The inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation according to claim 1, characterized in that, The perovskite solar cell has a PIN structure, comprising, from bottom to top, a transparent conductive substrate or an opaque substrate, a hole transport layer, a perovskite light-absorbing layer, a passivation layer, an electron transport layer, a buffer layer, and electrodes stacked sequentially. The perovskite light-absorbing layer simultaneously satisfies the following conditions: a. the perovskite light-absorbing layer is a CsPbI X Br 3-X inorganic perovskite film of the type b. The thickness of the perovskite light-absorbing layer is 400 nm-500 nm; The passivation layer is obtained by passivating the perovskite light-absorbing layer with indolebutyric acid using a dual-solvent assisted process.

3. An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation according to claim 1 or 2, characterized in that, The method for obtaining the passivation layer by using dual solvent-assisted indolebutyric acid to passivate the perovskite light-absorbing layer is as follows: Indolebutyric acid was dissolved in isopropanol at concentrations of 0.1–5 mg / mL and in methanol at concentrations of 0.1–5 mg / mL, and then spin-coated sequentially onto CsPbI. X Br 3-X For inorganic perovskite thin film surfaces, the spin coating speed of indolebutyric acid isopropanol solution is 3000-5000 r / min, and the spin coating time is 20-60 s. The indolebutyric acid methanol solution was spin-coated at a speed of 3000-5000 r / min for 20-60 s. The spin-coated films were then annealed at a temperature of 70-150 ℃ for 1-10 min to obtain an inorganic perovskite surface passivation layer.

4. An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation according to claim 1, characterized in that, The transparent conductive substrate is selected from one of ITO conductive glass, transparent conductive glass, transparent conductive flexible plastic, and conductive flexible stainless steel; The opaque conductive substrate is selected from one of the following: silicon heterojunction bottom cell, tunneling oxide contact silicon bottom cell, back contact silicon bottom cell, and copper indium gallium selenide cell.

5. An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation according to claim 1, characterized in that, The hole transport layer is made of NiO. X One of PTAA, P3CT-N, and SAM.

6. An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation according to claim 1, characterized in that, The electron transport layer is made of materials selected from PCBM, C 60 One of SnO2.

7. An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation according to claim 1, characterized in that, The material of the buffer layer is either BCP or SnO2.

8. An inorganic perovskite solar cell based on dual-solvent-assisted indolebutyric acid passivation according to claim 1, characterized in that, The electrode simultaneously satisfies the following conditions: a. The electrode is a metal electrode prepared by thermal evaporation or a screen-printed electrode; b. The electrode thickness is 10 nm-1000 nm; c. The electrode is a full-area metal electrode or a metal grid line.

9. A method for preparing inorganic perovskite solar cells based on dual-solvent-assisted indolebutyric acid passivation as described in any one of claims 1-8, characterized in that, A transparent conductive substrate or an opaque substrate, a hole transport layer, a perovskite light-absorbing layer, a passivation layer, an electron transport layer, a buffer layer, and electrodes are stacked sequentially from bottom to top; wherein... The perovskite light-absorbing layer simultaneously satisfies the following conditions: a. The perovskite light-absorbing layer is CsPbI. X Br 3-X Type of inorganic perovskite thin film; b. The thickness of the perovskite light-absorbing layer is 400 nm-500 nm; The perovskite light-absorbing layer is passivated by indolebutyric acid with dual solvent assistance to obtain a passivation layer. The preparation method is as follows: Indolebutyric acid was dissolved in isopropanol at concentrations of 0.1–5 mg / mL and in methanol at concentrations of 0.1–5 mg / mL, and then spin-coated sequentially onto CsPbI. X Br 3-X For inorganic perovskite thin film surfaces, the spin coating speed of indolebutyric acid isopropanol solution is 3000-5000 r / min, and the spin coating time is 20-60 s. The indolebutyric acid methanol solution was spin-coated at a speed of 3000-5000 r / min for 20-60 s. The spin-coated films were then annealed at a temperature of 70-150 ℃ for 1-10 min to obtain an inorganic perovskite surface passivation layer.

10. An application of a dual-solvent-assisted indolebutyric acid passivation method on the interface of the light-absorbing layer of an inorganic perovskite solar cell, characterized in that... The passivation layer obtained by the dual-solvent-assisted indolebutyric acid passivation method is suitable for the following structural devices: a. Invert-type perovskite-free single-junction solar cell; b. Inorganic perovskite / perovskite tandem solar cells; c. Inorganic perovskite / crystalline silicon tandem solar cells; d. Inorganic perovskite / copper indium gallium selenide tandem solar cells.

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