An interface-modified perovskite solar cell and its fabrication method

Abstract

This invention discloses an interface-modified perovskite solar cell and its fabrication method. The perovskite solar cell comprises a substrate, an electron transport layer, an interface modification layer, a perovskite light-absorbing layer, a hole transport layer, and an electrode layer arranged sequentially in layers. The interface modification layer is an organic molecule modification layer, and the material of the organic molecule modification layer is an organic compound or its organic salt containing sulfonic acid groups or carboxylic acid groups. By introducing the interface modification layer, this invention can effectively reduce the trapped states at the interface between the electron transport layer and the perovskite polycrystalline film, thereby promoting energy level matching between the electron transport layer and the perovskite light-absorbing layer, reducing the potential barrier between the electron transport layer and the perovskite polycrystalline film, thus reducing nonradiative recombination of charge carriers at the interface and facilitating efficient charge transport. The introduction of this interface modification layer also leads to an increase in the grain size of the perovskite polycrystalline film, significantly improving the crystallinity and stability of the perovskite polycrystalline film, and promoting the improvement of the performance of the perovskite solar cell.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, and more particularly to an interface-modified perovskite solar cell and its preparation method. Background Technology

[0002] Compared to traditional monocrystalline silicon solar cells, dye-sensitized solar cells, and organic solar cells, perovskite solar cells offer advantages such as solution-processable fabrication, low manufacturing costs, and applicability to flexible devices, making them more suitable for future commercial applications and meeting a wider range of market demands. Furthermore, perovskite materials possess long carrier diffusion lengths, tunable band gaps (0.5–3.5 eV), and low exciton binding energies, attracting increasing attention from research and industry. Since their application in solar cells began in 2009, perovskite materials have seen their efficiency rise from 3.8% to 26.1%, a remarkably rapid development that has made history in the photovoltaic field. However, while perovskite solar cells are an ideal choice for next-generation photovoltaic devices, current fabrication limitations mean that the perovskite light-absorbing layer is predominantly polycrystalline. This inevitably leads to various defects within the perovskite layer and at the interface, which trap carriers and cause unnecessary non-radiative recombination, resulting in reduced device performance. It also hinders the large-area fabrication of perovskite films with low defect state densities, severely impeding their commercial application. Summary of the Invention

[0003] The present invention aims to overcome the shortcomings and deficiencies of the prior art and provides an interface-modified perovskite solar cell and its preparation method. The perovskite solar cell provided by the present invention has good performance and stability.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] An interface-modified perovskite solar cell includes a substrate arranged in sequential layers;

[0006] An electron transport layer disposed on the surface of the substrate;

[0007] An interface modification layer disposed on the surface of the electron transport layer;

[0008] A perovskite light-absorbing layer disposed on the surface of the interface modification layer;

[0009] A hole transport layer disposed on the surface of the perovskite light-absorbing layer;

[0010] An electrode layer disposed on the surface of the hole transport layer;

[0011] The interface modification layer is an organic molecule modification layer, and the material of the organic molecule modification layer is an organic compound or its organic salt containing sulfonic acid groups or carboxylic acid groups.

[0012] Preferably, the material of the organic molecular modification layer is selected from one of pyrroloquinoline benzoquinone sodium salt, sodium 2-hydroxy-7-naphthalenesulfonate, disodium dihydroxynaphthalate monohydrate (piperamide sodium salt), 2-amino-3-carboxy-1,4-naphthoquinone, and pyrroloquinoline quinone acid.

[0013] The interface modification layer proposed in this invention can effectively reduce the trapped states at the interface between the electron transport layer and the perovskite polycrystalline film, thereby promoting energy level matching between the electron transport layer and the perovskite light-absorbing layer, reducing the potential barrier between the electron transport layer and the perovskite polycrystalline film, and thus reducing nonradiative recombination of charge carriers at the interface, which is beneficial for efficient charge transport. The introduction of this interface modification layer also leads to an increase in the grain size of the perovskite polycrystalline film, significantly improving its crystallinity and stability, and thus enhancing the performance of perovskite solar cells.

[0014] Preferably, the interface modification layer is prepared by the following steps: applying an organic molecule modification solution to the surface of the electron transport layer and then performing heat treatment to obtain the interface modification layer; the solvent of the organic molecule modification solution is water, and the concentration of the organic molecule modification solution is 0.2-1 mg / mL.

[0015] Further optimization is achieved by using the following heat treatment conditions: a heat treatment temperature of 80℃~120℃ and a heat treatment time of 5~30 minutes.

[0016] Preferably, the thickness of the interface modification layer is 2–10 nm.

[0017] Preferably, the thickness of the electron transport layer is 10–40 nm; the thickness of the perovskite light-absorbing layer is 500–800 nm; the thickness of the hole transport layer is 100–300 nm; and the thickness of the electrode layer is 50–150 nm.

[0018] Preferably, the substrate is a conductive substrate; the material of the conductive substrate is selected from FTO transparent conductive glass, ITO transparent conductive glass, ITO transparent conductive PEN, or ITO transparent conductive PET; the electron transport layer is made of tin dioxide; the perovskite light-absorbing layer is made of metal halide perovskite, the crystal structure of which is ABX3, where A is selected from at least one of organic or inorganic cations, B is selected from divalent metal ions, and X is selected from halide ions; the hole transport layer is made of one or more of Spiro-OMeTAD and PTAA; and the electrode layer is made of at least one of gold, silver, copper, carbon electrodes, and transparent conductive oxide electrodes.

[0019] This invention also protects a method for preparing the interface-modified perovskite solar cell, comprising the following steps:

[0020] Electron transport layers are prepared on substrate surfaces using chemical bath deposition, atomic layer deposition, or spin coating methods.

[0021] An interface modification layer is prepared on the surface of the electron transport layer;

[0022] A perovskite light-absorbing layer was prepared by coating the surface of the interface modification layer;

[0023] A hole transport layer was prepared on the surface of the perovskite absorber layer by spin coating.

[0024] An electrode layer is prepared on the surface of the hole transport layer by vapor deposition.

[0025] Preferably, the interface modification layer is prepared by the following steps: applying an organic molecule modification solution to the surface of the electron transport layer and then performing heat treatment to obtain the interface modification layer; the solvent of the organic molecule modification solution is water, and the concentration of the organic molecule modification solution is 0.2-1 mg / mL.

[0026] Further optimization is achieved by using the following heat treatment conditions: a heat treatment temperature of 80℃~120℃ and a heat treatment time of 5~30 minutes.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The interface modification layer proposed in this invention is placed on top of the electron transport layer, which improves the wettability of the perovskite precursor on its surface, reduces the contact angle, promotes perovskite crystallization and the formation of larger grains, and significantly improves the crystallinity and stability of the perovskite film. Furthermore, the introduction of the interface modification layer allows organic groups to interact with uncoordinated Pb... 2+ With a large coordination binding energy, the density of trapped states at the interface between the electron transport layer and the perovskite polycrystalline film is reduced, thereby reducing the energy shift at the interface and the potential difference between the electron transport layer and the perovskite polycrystalline film. This reduces the nonradiative recombination of charge carriers at the interface, which is more conducive to charge transport and provides a bright prospect for obtaining high-efficiency perovskite solar cells. Attached Figure Description

[0029] Figure 1 The figures show the efficiency stability curves of the perovskite solar cells in Comparative Examples 1, 2, and 1-3 of this invention. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are considered to be commercially available through conventional markets. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0031] This invention provides an interface-modified perovskite solar cell, comprising:

[0032] Base;

[0033] An electron transport layer disposed on the surface of the substrate;

[0034] An interface modification layer disposed on the surface of the electron transport layer;

[0035] A perovskite light-absorbing layer is set on the surface of the interface modification layer;

[0036] A hole transport layer disposed on the surface of the perovskite light-absorbing layer;

[0037] An electrode layer disposed on the surface of the hole transport layer.

[0038] In this invention, the substrate is preferably glass or a flexible conductive substrate; the substrate material is preferably selected from FTO transparent conductive glass, ITO transparent conductive glass, ITO transparent conductive PEN, or ITO transparent conductive PET; the sheet resistance of the substrate is preferably 7–30 Ωsq. -1 More preferably 7Ωsq -1 .

[0039] In this invention, the material of the electron transport layer is preferably selected from tin dioxide; the thickness of the electron transport layer is preferably 10-40 nm, more preferably 20-30 nm, and most preferably 25 nm.

[0040] In this invention, the material of the interface modification layer is an organic compound with sulfonic acid groups or carboxylic acid groups, preferably selected from one or more of pyrroloquinoline benzoquinone sodium salt, sodium 2-hydroxy-7-naphthalenesulfonate, disodium dihydroxynaphthalate monohydrate (piperamide sodium salt), 2-amino-3-carboxy-1,4-naphthoquinone and pyrroloquinoline quinone acid.

[0041] In this invention, the thickness of the interface modification layer is preferably 2-10 nm, more preferably 4-8 nm, and most preferably 5-6 nm.

[0042] In this invention, the material of the perovskite light-absorbing layer is preferably selected from metal halide perovskites; the crystal structure (composition formula) of the halide perovskite is preferably ABX3; A is selected from at least one of organic cations or inorganic cations, more preferably from at least one of formamidinium ion (FA), methylamine ion (MA), and cesium ion (Cs); B is selected from divalent metal ions, more preferably from lead ion (Pb). 2+ X is selected from halide ions, more preferably from iodide ions (I₂). - ), bromide ions (Br) - ), chloride ions (Cl) - At least one of the following.

[0043] In this invention, the thickness of the perovskite light-absorbing layer is preferably 500-800 nm, more preferably 600-700 nm, and most preferably 650 nm.

[0044] In this invention, the material of the hole transport layer is preferably selected from Spiro-OMeTAD (2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene) and / or PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]).

[0045] In this invention, the thickness of the hole transport layer is preferably 100-300 nm, more preferably 150-250 nm, and most preferably 200 nm.

[0046] In this invention, the electrode layer is preferably made of at least one of gold, silver, copper, carbon electrode, and transparent conductive oxide electrode. The thickness of the electrode layer is preferably 50–150 nm, more preferably 80–120 nm, and most preferably 100 nm.

[0047] This invention provides a method for preparing an interface-modified perovskite solar cell, comprising the following steps:

[0048] An electron transport layer is prepared on the substrate surface;

[0049] An interface modification layer is prepared on the surface of the electron transport layer;

[0050] A perovskite light-absorbing layer is prepared on the surface of the interface modification layer;

[0051] A hole transport layer is prepared on the surface of a perovskite light-absorbing layer;

[0052] An electrode layer is fabricated on the surface of the hole transport layer.

[0053] In this invention, the method for preparing the above-mentioned interface-modified perovskite solar cell preferably includes the following steps:

[0054] An electron transport layer is formed on the surface of a conductive substrate;

[0055] An interface modification layer is formed on the surface of the electron transport layer;

[0056] A perovskite light-absorbing layer is prepared on the surface of the interface modification layer;

[0057] A hole transport layer is formed on the surface of the perovskite light-absorbing layer;

[0058] An electrode layer is fabricated on the surface of the hole transport layer.

[0059] In this invention, the substrate is preferably an FTO glass substrate, and the substrate is preferably cleaned and treated; the cleaning is preferably done in one step using a glass cleaner plus deionized water, deionized water, ethanol and isopropanol; after cleaning, it is preferably dried; the treatment is preferably ultraviolet-ozone treatment; the treatment time is preferably 10 to 20 minutes, more preferably 15 minutes.

[0060] In this invention, the method for preparing the electron transport layer is preferably selected from chemical bath deposition, atomic layer deposition, or spin coating, and more preferably spin coating.

[0061] In this invention, the preferred method for preparing the electron transport layer includes: diluting a commercially available aqueous solution of 15% tin dioxide nanoparticles with deionized water to 2%–3%, preferably 2.67%.

[0062] In this invention, a diluted aqueous solution of tin dioxide nanoparticles is filtered and spin-coated onto a conductive substrate, followed by annealing and drying to obtain an electron transport layer. The spin-coating time is preferably 25–35 s, the spin speed is preferably 2500–4000 rpm, more preferably 30 s, and more preferably 3000 rpm. The annealing temperature is preferably 120°C–180°C, more preferably 150°C; the annealing time is preferably 60 minutes, more preferably 30 minutes. The electron transport layer is then dried at 150°C for 30 minutes.

[0063] In this invention, the preferred method for preparing the interface modification layer includes: applying an organic molecular solution to the surface of an electron transport layer and then performing heat treatment to obtain the interface modification layer.

[0064] In this invention, the solvent in the organic molecular solution is preferably selected from water; the concentration of the organic molecular solution is preferably 0.2–1.0 mg / mL, more preferably 0.3–0.8 mg / mL, and most preferably 0.4–0.6 mg / mL. In this invention, the method for preparing the organic molecular solution preferably includes: dissolving organic molecules in a solvent to obtain a solution required for interface modification; the composition of the solution is consistent with that described in the above technical solution and will not be repeated here.

[0065] In this invention, the heat treatment temperature is preferably 80℃~120℃, more preferably 90℃~110℃, and most preferably 100℃; the heat treatment time is preferably 5~30 minutes, more preferably 10~25 minutes, and most preferably 20 minutes.

[0066] In this invention, the preferred method for preparing the perovskite light-absorbing layer includes: coating a perovskite solution onto the surface of an interface modification layer and then annealing it to obtain the perovskite absorption layer.

[0067] In this invention, the solute in the perovskite solution is preferably selected from cesium iodide, lead iodide, dimethylamine hydroiodate, etc.; the solvent in the perovskite solution is preferably selected from one or more of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide); the molar concentration of the perovskite solution is preferably 1.2 to 1.6 mol / L, more preferably 1.3 to 1.5 mol / L.

[0068] In this invention, it is preferred to drop the perovskite solution onto the substrate (interface modification layer) and perform a two-step spin coating; the rotation speeds during the two-step spin coating process are preferably 500-1500 rpm and 4000-6000 rpm, and most preferably 1000 rpm and 5000 rpm; the spin coating times are preferably 5-15 s and 20-40 s, and most preferably 10 s and 30 s.

[0069] In this invention, the annealing temperature is preferably 100°C; the annealing time is preferably 30 to 90 minutes, and most preferably 60 minutes.

[0070] In this invention, the preferred method for preparing the hole transport layer includes: spin-coating a precursor solution onto the surface of a perovskite light-absorbing layer to obtain the hole transport layer.

[0071] In this invention, the solute in the precursor solution is preferably selected from Spiro-OMeTAD, 4-tert-butylpyridine, and lithium bis(trifluoromethanesulfonylimide) solution (520 mg / mL). -1 (dissolved in acetonitrile); the solvent in the precursor solution is preferably selected from chlorobenzene; the mass concentration of the precursor solution is preferably Spiro-OMeTAD: 50-100 mg / mL. -1 Preferably 60–90 mg / mL -1 More preferably 70–80 mg / mL -1 4-tert-butylpyridine: 30–50 μL / mL -1 Preferably 35–45 μL / mL -1 More preferably 40 μL mL -1 Lithium bis(trifluoromethanesulfonyl)imide solution: 20–30 μL / mL -1 Preferably 22–26 μL / mL -1 More preferably 23 μL / mL-1 .

[0072] In this invention, the spin coating speed is preferably 2500-3500 rpm, more preferably 2800-3200 rpm, and most preferably 3000 rpm; the spin coating time is preferably 20-40 s, more preferably 25-35 s, and most preferably 30 s.

[0073] In this invention, the preferred method for preparing the electrode layer includes: preparing the electrode layer on the hole transport layer by vacuum evaporation.

[0074] In this invention, the vacuum degree during the vacuum evaporation process is preferably below 10. -4 Pa, deposition rate preferably More preferably

[0075] This invention employs organic small molecules to modify the electron transport layer of tin oxide, improving the wettability of the perovskite precursor on its surface, reducing the contact angle, promoting perovskite crystallization and forming larger grains, and significantly improving the crystallinity and stability of the perovskite film. Furthermore, the introduction of the organic interface modification layer, with its multifunctional organic functional groups interacting with uncoordinated Pb... 2+ With a large binding energy, the density of trapped states at the interface between the electron transport layer and the perovskite polycrystalline film is reduced, thereby reducing the energy shift at the interface and the potential difference between the electron transport layer and the perovskite polycrystalline film. This reduces the nonradiative recombination of charge carriers at the interface, which is more conducive to charge transport and provides a bright prospect for obtaining high-efficiency perovskite solar cells.

[0076] Example 1:

[0077] The FTO glass substrate was cleaned sequentially with glass cleaner containing deionized water, deionized water, ethanol, and isopropanol. It was then dried with nitrogen and treated with UV-ozone for 15 minutes. A commercially available 15% (w / w) aqueous solution of tin dioxide nanoparticles was diluted to 2.67% with deionized water, filtered, and spin-coated onto the conductive glass layer (FTO glass) at 30 s spin time and 3000 rpm. The layer was then dried at 150°C for 30 min to obtain the electron transport layer.

[0078] A concentration of 0.4 mg / mL -1 After the sodium pyrroloquinoline benzoquinone salt solution was applied to the surface of the electron transport layer, it was heat-treated at 100°C for 20 minutes to obtain the interface modification layer.

[0079] The perovskite precursor solution was spin-coated onto the electron transport layer in a nitrogen glove box (two-step spin-coating: the first spin-coating time was 10 s at 1000 rpm, and the second spin-coating time was 30 s at 4000 rpm). Ethyl acetate was added dropwise as an anti-solvent during the spin-coating process. Then, the mixture was annealed at 100 °C for 60 min to form a perovskite polycrystalline film. The perovskite composition was (FAPbI3). 0.95 (MAPbBr3) 0.05 The perovskite precursor solution was prepared by dissolving 1.53 M PbI2, 1.4 M FAI, 0.5 M MACl and 0.07 M MAPbBr3 in a mixed solvent of DMF and DMSO (the volume ratio of DMF to DMSO was 8:1).

[0080] Dissolve 72 mg Spiro-OMeTAD and 39 μL 4-tert-butylpyridine in 1 mL of chlorobenzene, then add 23 μL of 520 mg / mL solution. -1 A solution of lithium bis(trifluoromethanesulfonylimide) in acetonitrile was thoroughly mixed and spin-coated at 3000 rpm for 30 s onto a perovskite light-absorbing layer. Finally, a gold electrode was prepared by vacuum evaporation at a vacuum level below 10. -4 Pa, deposition rate Perovskite solar cells were obtained.

[0081] In a perovskite solar cell, the electron transport layer is 25 nm thick, the interface modification layer is 5–6 nm thick, the perovskite layer is 650 nm thick, the hole transport layer is 120 nm thick, and the gold electrode is 80 nm thick.

[0082] Comparative Example 1:

[0083] Perovskite solar cells were prepared according to the method of Example 1, except that no interface modification layer was used.

[0084] Comparative Example 2:

[0085] Perovskite solar cells were prepared according to the method of Example 1, except that no interface modification layer was used. The perovskite precursor solution was prepared by dissolving 1.53 M PbI2, 1.4 M FAI, 0.5 M MACl, 0.07 M MAPbBr3 and 0.4 mg of pyrroloquinoline benzoquinone sodium salt in a mixed solvent of DMF and DMSO = 8:1 (1 mL).

[0086] Example 2:

[0087] Perovskite solar cells were prepared according to the method of Example 1, except that the organic molecular solution had a concentration of 0.6 mg / mL. -1The thickness of the interface modification layer is 5-6 nm, obtained from a sodium 2-hydroxy-7-naphthalenesulfonate solution.

[0088] Example 3:

[0089] Perovskite solar cells were prepared according to the method of Example 1, except that the organic molecular solution had a concentration of 0.5 mg / mL. -1 The thickness of the interface modification layer is 5-6 nm with a solution of disodium dihydroxynaphthalate monohydrate (sodium piperomorphate).

[0090] The efficiency stability curves of the solar cells in Example 1 and Examples 1-3 are shown below. Figure 1 As shown in the figure, the device efficiency is significantly improved after interface modification, especially the open-circuit voltage, fill factor, and short-circuit current.

[0091] Example 4:

[0092] Perovskite solar cells were prepared according to the method of Example 1, except that the organic molecular solution had a concentration of 0.5 mg / mL. -1 A solution of 2-amino-3-carboxy-1,4-naphthoquinone was used, and the thickness of the interface modification layer was 5–6 nm.

[0093] Example 5:

[0094] Perovskite solar cells were prepared according to the method of Example 1, except that the organic molecular solution had a concentration of 0.4 mg / mL. -1 The thickness of the interface modification layer is 5-6 nm, obtained from a pyrroloquinoline quinoline acid solution.

[0095] The photoelectric data for Comparative Example 1, Comparative Example 2, and Examples 1-5 are shown in Table 1. The testing equipment was an Autolab TYPE II electrochemical workstation and an ABET Sun 3000 solar simulator. The testing conditions were AM1.5 and 100 mW / cm². 2 .

[0096] Table 1

[0097]

[0098] As can be seen from Table 1, the efficiency of perovskite solar cells is significantly improved with the introduction of the interface modification layer, and the highest efficiency in Example 3 reaches 24.01%.

[0099] This invention selects an organic molecular layer as the interface modification layer material. The introduction of the interface modification layer reduces the contact angle of the perovskite precursor, promoting perovskite crystallization and resulting in larger grains. Simultaneously, the modification layer further enhances the energy level alignment between the ETL and the perovskite layer. The negatively charged sulfonic acid groups (-SO3) in the modification layer... - ) or carboxylic acid group (-COO) - It exhibits a more negative electrostatic potential, which is beneficial to -SO3 - or -COO - With uncoordinated Pb 2+ Strong interactions occur. The metal ions in organometallic salts can compensate for the cation defects in tin oxide (A), reducing device hysteresis. Furthermore, the quinone groups (-C=O) and hydroxyl groups (-OH) can further passivate uncoordinated tin and oxygen vacancy defects on the tin oxide surface, improving carrier extraction and transport. Therefore, the synergistic passivation effect of multiple functional groups in organic materials on perovskite significantly promotes a substantial improvement in device performance.

[0100] Example 6:

[0101] Perovskite solar cells were prepared according to the method of Example 1, the difference being that:

[0102] The preparation of the electron transport layer includes: diluting a commercially available 15% tin dioxide nanoparticle aqueous solution with deionized water to 2%, spin-coating for 25 s, rotating at 4000 rpm, annealing at 120 °C, and annealing for 60 minutes.

[0103] The preparation of the interface modification layer includes: the concentration of the organic molecule solution is preferably 0.3 mg / mL, the heat treatment temperature is 90℃, and the heat treatment time is 25 minutes.

[0104] The preparation of the perovskite light-absorbing layer includes: a perovskite solution is dropped onto a substrate (interface modification layer) and spin-coated in two steps; the spin speeds in the two spin-coating steps are 500 rpm and 4000 rpm, respectively; the spin-coating times in the two steps are 15 s and 40 s, respectively; the annealing temperature is 100℃; and the annealing time is 30 minutes.

[0105] The preparation of the hole transport layer includes: the solute in the precursor solution is a lithium bis(trifluoromethanesulfonylimide) solution (520 mg / mL). -1 (dissolved in acetonitrile); the precursor solution had a mass concentration of 23 μL / mL. -1 The spin coating speed was 3200 rpm; the spin coating time was 20 s.

[0106] The preparation of the electrode layer includes: a vacuum degree of less than 10 during the vacuum evaporation process. -4 Pa, deposition rate is

[0107] The electron transport layer has a thickness of 40 nm; the interface modification layer has a thickness of 4–5 nm; the perovskite light-absorbing layer has a thickness of 800 nm; the hole transport layer has a thickness of 300 nm; and the electrode layer has a thickness of 150 nm.

[0108] Example 7:

[0109] Perovskite solar cells were prepared according to the method of Example 1, the difference being that:

[0110] The preparation of the electron transport layer includes: diluting a commercially available 15% tin dioxide nanoparticle aqueous solution with deionized water to 3%, with a spin coating time preferably of 35 s, a spin speed preferably of 2500 rpm, an annealing temperature of 180°C, and an annealing time of 30 minutes.

[0111] The preparation of the interface modification layer includes: the concentration of the organic molecule solution is 0.8 mg / mL, the heat treatment temperature is 110℃, and the heat treatment time is 10 minutes.

[0112] The preparation of the perovskite light-absorbing layer includes: a perovskite solution is dropped onto a substrate (interface modification layer) and spin-coated in two steps; the preferred rotation speeds during the two-step spin-coating process are 1500 rpm and 6000 rpm; the preferred spin-coating times are 5 s and 20 s; the annealing temperature is 100℃; and the annealing time is 90 minutes.

[0113] The preparation of the hole transport layer includes: a 4-tert-butylpyridine solution (520 mg / mL) as the solute in the precursor solution. -1 (dissolved in acetonitrile); the precursor solution had a mass concentration of 40 μL / mL. -1 The spin coating speed was 2800 rpm; the spin coating time was 35 s.

[0114] The preparation of the electrode layer includes: the vacuum degree during the vacuum evaporation process is preferably below 10. -4 Pa, deposition rate preferably

[0115] The electron transport layer has a thickness of 10 nm; the interface modification layer has a thickness of 6–8 nm; the perovskite light-absorbing layer has a thickness of 500 nm; the hole transport layer has a thickness of 100 nm; and the electrode layer has a thickness of 50 nm.

[0116] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A perovskite solar cell with interface modification, characterized in that, Includes a substrate arranged in layers; An electron transport layer disposed on the surface of the substrate; An interface modification layer disposed on the surface of the electron transport layer; A perovskite light-absorbing layer disposed on the surface of the interface modification layer; A hole transport layer disposed on the surface of the perovskite light-absorbing layer; An electrode layer disposed on the surface of the hole transport layer; The interface modification layer is an organic molecule modification layer, and the material of the organic molecule modification layer is selected from either sodium pyrroloquinoline benzoquinone or pyrroloquinoline quinone acid. The interface modification layer is prepared by the following steps: the organic molecule modification solution is coated onto the surface of the electron transport layer and then heat-treated to obtain the interface modification layer; the solvent of the organic molecule modification solution is water, the concentration of the organic molecule modification solution is 0.2~1 mg / mL, and the heat treatment conditions are: heat treatment temperature is 80℃~120℃, heat treatment time is 5~30 minutes, and the material of the electron transport layer is tin dioxide.

2. The perovskite solar cell according to claim 1, characterized in that, The thickness of the interface modification layer is 2~10 nm.

3. The perovskite solar cell according to claim 1, characterized in that, The electron transport layer has a thickness of 10-40 nm; the perovskite light-absorbing layer has a thickness of 500-800 nm; the hole transport layer has a thickness of 100-300 nm; and the electrode layer has a thickness of 50-150 nm.

4. The perovskite solar cell according to claim 1, characterized in that, The substrate is a conductive substrate; the perovskite light-absorbing layer is made of metal halide perovskite, and the crystal structure of the metal halide perovskite is ABX3, where A is selected from at least one of organic or inorganic cations, B is selected from divalent metal ions, and X is selected from halide ions; the hole transport layer is made of one or more of Spiro-OMeTAD and PTAA; and the electrode layer is made of at least one of gold, silver, copper, carbon electrodes, and transparent conductive oxide electrodes.

5. A method for preparing an interface-modified perovskite solar cell according to claim 1, characterized in that, Includes the following steps: Electron transport layers are prepared on substrate surfaces using chemical bath deposition, atomic layer deposition, or spin coating methods. An interface modification layer is prepared on the surface of the electron transport layer; A perovskite light-absorbing layer was prepared by coating the surface of the interface modification layer; A hole transport layer was prepared on the surface of the perovskite absorber layer by spin coating. An electrode layer is prepared on the surface of the hole transport layer by vapor deposition.

6. The preparation method according to claim 5, characterized in that, The interface modification layer is prepared by the following steps: an organic molecule modification solution is coated onto the surface of the electron transport layer and then subjected to heat treatment to obtain the interface modification layer; the solvent of the organic molecule modification solution is water, and the concentration of the organic molecule modification solution is 0.2~1 mg / mL.

7. The preparation method according to claim 6, characterized in that, The heat treatment conditions are: heat treatment temperature of 80℃~120℃, heat treatment time of 5~30 minutes.

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