A buried interface modified wide-bandgap perovskite solar cell and a preparation method thereof

Abstract

This invention provides a wide-bandgap perovskite solar cell with a buried interface modification and its fabrication method, belonging to the field of solar cell technology. The wide-bandgap perovskite solar cell with a buried interface modification comprises, from bottom to top, a conductive substrate, a hole transport layer, a buried interface modification layer, a wide-bandgap perovskite absorber layer, a back interface modification layer, an electron transport layer, a buffer layer, and a metal electrode layer; the material of the buried interface modification layer is an amide oxime compound. This invention also includes a method for fabricating the wide-bandgap perovskite solar cell with a buried interface modification. The wide-bandgap perovskite solar cell with a buried interface modification prepared by this invention has fewer interface defects at the hole transport layer / wide-bandgap perovskite absorber layer, exhibits good performance in terms of non-radiative loss and charge transfer loss, and has high photoelectric conversion efficiency, showing broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a wide-bandgap perovskite solar cell with buried interface modification and its preparation method. Background Technology

[0002] Wide-bandgap perovskite solar cells are a novel type of solar cell based on perovskite structural materials, offering advantages such as high efficiency, low cost, and ease of fabrication. The structure of these solar cells typically involves multiple functional layers stacked sequentially from bottom to top, including a conductive substrate, a hole transport layer, a perovskite absorber layer, an electron transport layer, a buffer layer, and a metal electrode layer. The perovskite absorber layer is the core component of the solar cell, responsible for absorbing sunlight and generating photogenerated carriers. Wide-bandgap perovskite solar cells have attracted widespread attention due to their high open-circuit voltage and short-circuit current, potentially leading to high photoelectric conversion efficiency. Furthermore, perovskite materials possess a rich elemental composition and a tunable bandgap, providing ample room for optimizing solar cell performance.

[0003] Despite the numerous advantages of wide-bandgap perovskite solar cells, some shortcomings still need to be addressed. The interfacial stability between the perovskite material and adjacent functional layers is one of the key factors affecting the long-term performance of solar cells. Chemical reactions, element diffusion, or interfacial defects at the interface may lead to an increase in carrier recombination rate. At the same time, the carrier transport efficiency between the perovskite absorber layer and adjacent functional layers also directly affects the performance of solar cells. Energy level mismatch or transport barriers at the interface may lead to carrier loss and reduce photoelectric conversion efficiency.

[0004] To address these issues, existing technologies often employ interface modifiers to modify the interface of wide-bandgap perovskite solar cells, thereby improving device performance and stability. However, interface modifiers are typically used between the wide-bandgap perovskite absorber layer and the electron transport layer, and their effects are mostly focused on reducing the on-voltage loss of the wide-bandgap perovskite. Nevertheless, severe interfacial nonradiative recombination still exists at the interface between the wide-bandgap perovskite absorber layer and the hole transport layer, resulting in poor interfacial transport quality and a low fill factor. This leads to poor performance and stability in wide-bandgap perovskite solar cells. Therefore, solving these problems and fabricating high-performance, highly stable wide-bandgap perovskite solar cells remains a crucial technical challenge. Summary of the Invention

[0005] The problem this invention aims to solve is to provide a wide-bandgap perovskite solar cell with a buried interface modification and its preparation method, in order to address the issues of severe non-radiative loss and poor interface transport quality at the interface between the perovskite absorber layer and the hole transport layer in wide-bandgap perovskite solar cells.

[0006] The technical solution adopted to solve the technical problem is to provide a wide-bandgap perovskite solar cell with buried interface modification. The wide-bandgap perovskite solar cell with buried interface modification includes a conductive substrate, a hole transport layer, a buried interface modification layer, a wide-bandgap perovskite absorber layer, a back interface modification layer, an electron transport layer, a buffer layer and a metal electrode layer stacked sequentially from bottom to top.

[0007] The material of the embedded interface modification layer is an amide oxime compound.

[0008] The beneficial effects of the above-mentioned technical solution of this invention are as follows: This invention focuses on interface modification at the buried interface. The buried interface is modified between the hole transport layer and the wide-bandgap perovskite absorber layer of a wide-bandgap perovskite solar cell. After modification with amide oxime compounds, the surface hydrophobicity of the hole transport layer is enhanced, which is beneficial to the crystallization and growth of the perovskite layer. The modification reduces defects at the buried interface, promotes hole extraction, reduces non-radiative recombination, and improves the fill factor and photoelectric conversion efficiency of the solar cell. Simultaneously, amide oxime compounds can form hydrogen bonds and tightly bind with the hole transport layer, thereby improving the charge transport efficiency and stability of the interface. Furthermore, amide oxime compounds contain -NH2 groups that can passivate defects in the perovskite layer, further improving the growth quality of the perovskite film and the stability of the cell.

[0009] Preferably, the amide oxime compound is (Z)-4-fluorobenzamide oxime.

[0010] The beneficial effects of the above-mentioned technical solution in this invention are as follows: the oxime group (-C=NOH) in the (Z)-4-fluorobenzamide oxime molecule endows it with unique reactivity and interface modification ability. These groups can interact with specific sites in perovskite materials, thereby affecting the growth process and final quality of perovskite films; the amino group can provide free electron pairs, which can interact with uncoordinated Pb in wide-bandgap perovskites. 2+ Coordination bonds are formed, regulating the crystallization of thin films.

[0011] Preferably, the conductive substrate is made of ITO conductive glass; the hole transport layer is made of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate; and the wide-bandgap perovskite absorber layer is made of Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 3; the material of the post-interface modification layer is 1,3-diaminopropane dihydroiodate; the material of the electron transport layer is C. 60 The buffer layer is made of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; the metal electrode layer is made of copper.

[0012] The present invention also provides a method for preparing the above-mentioned wide-bandgap perovskite solar cell with buried interface modification, comprising the following steps:

[0013] (1) The hole transport layer solution was spin-coated onto a pre-cleaned conductive substrate and annealed to obtain a hole transport layer; the hole transport layer solution was an organic solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid;

[0014] (2) Dissolve the amyloxime compound in an organic solvent to obtain a substrate interface treatment solution;

[0015] (3) Spin-coating the buried interface treatment solution onto the hole transport layer and annealing it to obtain the buried interface modification layer.

[0016] (4) A wide-bandgap perovskite precursor solution was spin-coated onto the subsurface interface modification layer using an anti-solvent method and then annealed to obtain a wide-bandgap perovskite absorber layer; the wide-bandgap perovskite precursor solution was Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3 organic solutions;

[0017] (5) Spin-coating the post-interface treatment solution onto the wide-bandgap perovskite absorber layer and annealing it to obtain the post-interface modified layer; the post-interface treatment solution is an organic solution of 1,3-diaminopropane dihydroiodate.

[0018] (6) An electron transport layer, a buffer layer and a metal electrode layer are sequentially deposited on the surface of the back interface modification layer by thermal evaporation to obtain the desired result.

[0019] Preferably, in step (1), the organic solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid is an ethanol solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid with a mass concentration of 0.3~0.8 mg / mL; the spin coating speed in step (1) is 2500~3500 rpm, the time is 10~20 s; the annealing temperature is 90~110℃, and the time is 8~12 min.

[0020] More preferably, in step (1), the organic solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid is an ethanol solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid with a mass concentration of 0.5 mg / mL; in step (1), the spin coating speed is 3000 rpm and the time is 20 s; the annealing temperature is 100℃ and the time is 10 min.

[0021] Preferably, the organic solvent in step (2) is isopropanol; the mass concentration of the submerged interface treatment solution is 0.5~2 mg / mL.

[0022] More preferably, the mass concentration of the submerged interface treatment solution is 1 mg / mL.

[0023] Preferably, in step (3), the spin coating speed is 3500~4500 rpm and the time is 20~30 s; the annealing temperature is 50~70℃ and the time is 4~6 min.

[0024] More preferably, in step (3), the spin coating speed is 4000 rpm and the time is 30 s; the annealing temperature is 60℃ and the time is 5 min.

[0025] Preferably, step (4) includes the following steps: a wide-bandgap perovskite precursor solution is dropped onto the buried interface modification layer and a first spin coating is performed at 400-600 rpm for 1-3 s, followed by a second spin coating at 3000-4000 rpm for 30-50 s, and diethyl carbonate is dropped onto the second spin coating at 15-20 s; after spin coating, the mixture is placed at 50-70℃ for a first annealing for 1-3 min, and then placed at 90-110℃ for a second annealing for 4-6 min.

[0026] More preferably, step (4) includes the following steps: a wide-bandgap perovskite precursor solution is dropped onto the buried interface modification layer for a first spin coating at 500 rpm for 2 s, followed by a second spin coating at 4000 rpm for 40 s, and diethyl carbonate is dropped onto the second spin coating at the 20th s; after spin coating, the mixture is placed at 60°C for a first annealing for 2 min, and then placed at 100°C for a second annealing for 5 min.

[0027] Preferably, in step (5), the organic solution of 1,3-diaminopropane dihydroiodate is an isopropanol solution of 1,3-diaminopropane dihydroiodate with a mass concentration of 0.5~2 mg / mL; in step (5), the spin coating speed is 2000~4000 rpm and the time is 20~40 s; the annealing temperature is 90~110℃ and the time is 4~6 min.

[0028] Preferably, in step (5), the organic solution of 1,3-diaminopropane dihydroiodate is an isopropanol solution of 1,3-diaminopropane dihydroiodate with a mass concentration of 1 mg / mL; in step (5), the spin coating speed is 3000 rpm and the time is 30s; the annealing temperature is 100℃ and the time is 5 min.

[0029] Preferably, the deposition rate in step (6) is 0.05~0.2 Å / s; the deposition thickness of the electron transport layer is 15~25 nm, the deposition thickness of the buffer layer is 4~6 nm, and the deposition thickness of the metal electrode layer is 90~110 nm.

[0030] More preferably, the deposition rate in step (6) is 0.1 Å / s; the deposition thickness of the electron transport layer is 20 nm, the deposition thickness of the buffer layer is 5 nm, and the deposition thickness of the metal electrode layer is 100 nm.

[0031] The present invention has the following beneficial effects:

[0032] (1) The buried interface modified wide-bandgap perovskite solar cell prepared by the present invention modifies the buried interface, focusing on improving the interface transport quality and fill factor. The surface hydrophobicity of the hole transport layer after the buried interface modification is increased, which is conducive to the high-quality growth of perovskite thin film and solves the problem of poor device stability.

[0033] (2) The hole transport layer / wide bandgap perovskite absorber layer interface of the buried interface modified by the present invention has few defects, performs well in terms of non-radiative loss and charge transfer loss, and has high photoelectric conversion efficiency, and has broad application prospects. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the wide-bandgap perovskite solar cell with buried interface modification prepared in this invention.

[0035] Figure 2 These are the wide-bandgap perovskite solar cells with buried interface modification prepared in Example 1 and Comparative Example 1. JV Line graph;

[0036] Figure 3 The light intensity of the wide-bandgap perovskite solar cells with buried interface modification prepared in Example 1 and Comparative Example 1 is... V OC Measurement map;

[0037] Figure 4 The above are EQE curves of the wide-bandgap perovskite solar cells with buried interface modification prepared in Example 1 and Comparative Example 1. Detailed Implementation

[0038] The principles and features of the present invention are described below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products. (Z)-4-fluorobenzamide oxime, sourced from Bid Pharmaceuticals, CAS 69113-32-2; 1,3-diaminopropane dihydroiodic acid salt, sourced from Xi'an Baolai Pharmaceutical, CAS 120675-53-8; [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate, CAS 2882156-63-8.

[0039] Example 1

[0040] A wide-bandgap perovskite solar cell with buried interface modification comprises, from bottom to top, a conductive substrate made of ITO conductive glass, a hole transport layer made of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid, a buried interface modification layer made of (Z)-4-fluorobenzamide oxime, and a Cs-based... 0.2 FA 0.8 Pb(I 0.6 Br 0.4 The wide-bandgap perovskite absorber layer of 3, the back interface modification layer made of 1,3-diaminopropane dihydroiodate, and the material of C 60 The electron transport layer, the buffer layer made of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and the metal electrode layer made of copper metal.

[0041] Wide-bandgap perovskite solar cell device structure with buried interface modification, such as Figure 1 As shown.

[0042] The wide-bandgap perovskite solar cell with buried interface modification in this embodiment is prepared through the following steps:

[0043] (1) The 25 mm × 25 mm ITO conductive glass was pre-cleaned with ultrapure water and ethanol for 20 min, dried on a warm table, and then treated in a UV-O3 atmosphere for 20 min.

[0044] (2) Spin-coat an ethanol solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid with a mass concentration of 0.5 mg / mL onto a pre-cleaned ITO conductive glass at a spin-coating speed of 3000 rpm for 20 s, and then anneal at 100℃ for 10 min to obtain a hole transport layer.

[0045] (3) Dissolve (Z)-4-fluorobenzamide oxime in isopropanol so that the mass concentration of (Z)-4-fluorobenzamide oxime in isopropanol is 1 mg / mL to obtain the buried interface treatment solution.

[0046] (4) Spin-coating the buried interface treatment solution onto the cooled hole transport layer surface at a spin coating speed of 4000 rpm for 20 s, followed by annealing at 60℃ for 5 min to obtain the buried interface modification layer.

[0047] (5) CsI, FAI, PbBr2, and PbI2 are arranged according to Cs 0.2 FA 0.8 Pb(I 0.6 Br 0.4Weigh the proportions from 3 and dissolve them in a mixed solution of dimethylformamide and dimethyl sulfoxide in a volume ratio of 3:1 to obtain component Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3 1.77 eV wide-bandgap perovskite precursor solution;

[0048] (6) A wide-bandgap perovskite precursor solution was dropped onto the surface of the buried interface modification layer. The first spin coating was performed at a spin coating speed of 500 rpm for 2 s, and the second spin coating was performed at a spin coating speed of 4000 rpm for 40 s. Diethyl carbonate was dropped on the 20th s of the second spin coating. After the spin coating was completed, the layer was placed at 60℃ for the first annealing for 2 min, and then placed at 100℃ for the second annealing for 5 min to obtain a wide-bandgap perovskite absorption layer.

[0049] (7) Dissolve 1,3-diaminopropane dihydroiodate in isopropanol to make the mass concentration of 1,3-diaminopropane dihydroiodate 1 mg / mL to obtain the post-interface treatment solution.

[0050] (8) The post-interface treatment solution was spin-coated onto the surface of the wide-bandgap perovskite absorber layer at a spin-coating speed of 3000 rpm for 30 s, and then annealed at 100℃ for 5 min to obtain the post-interface modification layer.

[0051] (9) Heating C using thermal evaporation method 60 When the temperature reaches 530℃, C 60 The evaporation rate is 0.1 Å / s until C 60 An electron transport layer with a deposition thickness of 20 nm was obtained on the back interface modification layer.

[0052] (10) 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was heated to 100°C using atomic deposition, so that the evaporation rate of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was 0.1 Å / s, until the deposition thickness of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline on the electron transport layer was 5 nm, thus obtaining a buffer layer;

[0053] (11) The copper metal is heated by thermal evaporation to make the copper metal evaporation rate 0.1 Å / s until the copper metal deposition thickness on the buffer layer is 100 nm, thus obtaining the wide-bandgap perovskite solar cell with buried interface modification.

[0054] Example 2

[0055] A wide-bandgap perovskite solar cell with a buried interface modification has the same structure and material as in Example 1.

[0056] The wide-bandgap perovskite solar cell with buried interface modification in this embodiment is prepared through the following steps:

[0057] (1) The 25 mm × 25 mm ITO conductive glass was pre-cleaned with ultrapure water and ethanol for 20 min, dried on a warm table, and then treated in a UV-O3 atmosphere for 20 min.

[0058] (2) Spin-coat an ethanol solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid with a mass concentration of 0.3 mg / mL onto a pre-cleaned ITO conductive glass at a spin-coating speed of 2500 rpm for 10 s, and then anneal at 90℃ for 8 min to obtain a hole transport layer.

[0059] (3) Dissolve (Z)-4-fluorobenzamide oxime in isopropanol so that the mass concentration of (Z)-4-fluorobenzamide oxime in isopropanol is 0.5 mg / mL, to obtain the submerged interface treatment solution.

[0060] (4) Spin-coating the buried interface treatment solution onto the cooled hole transport layer surface at a spin coating speed of 3500 rpm for 20 s, followed by annealing at 50°C for 4 min to obtain the buried interface modification layer.

[0061] (5) CsI, FAI, PbBr2, and PbI2 are arranged according to Cs 0.2 FA 0.8 Pb(I 0.6 Br 0.4 Weigh the proportions from 3 and dissolve them in a mixed solution of dimethylformamide and dimethyl sulfoxide in a volume ratio of 3:1 to obtain component Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3 1.77 eV wide-bandgap perovskite precursor solution;

[0062] (6) A wide-bandgap perovskite precursor solution was dropped onto the surface of the buried interface modification layer. The first spin coating was performed at a spin coating speed of 400 rpm for 1 s, and the second spin coating was performed at a spin coating speed of 3000 rpm for 30 s. Diethyl carbonate was dropped on the 15th s of the second spin coating. After the spin coating was completed, the layer was placed at 50℃ for the first annealing for 1 min, and then placed at 90℃ for the second annealing for 4 min to obtain a wide-bandgap perovskite absorption layer.

[0063] (7) Dissolve 1,3-diaminopropane dihydroiodate in isopropanol to make the mass concentration of 1,3-diaminopropane dihydroiodate 0.5 mg / mL to obtain the post-interface treatment solution.

[0064] (8) The post-interface treatment solution was spin-coated onto the surface of the wide-bandgap perovskite absorber layer at a spin-coating speed of 2000 rpm for 20 s, and then annealed at 90℃ for 4 min to obtain the post-interface modification layer.

[0065] (9) Heating C using thermal evaporation method 60 When the temperature reaches 530℃, C 60 The evaporation rate was 0.05 Å / s until C 60 An electron transport layer with a deposition thickness of 15 nm was obtained on the back interface modification layer.

[0066] (10) 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was heated to 100°C using atomic deposition, so that the evaporation rate of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was 0.05 Å / s, until the deposition thickness of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline on the electron transport layer was 4 nm, thus obtaining a buffer layer;

[0067] (11) The copper metal is heated by thermal evaporation to make the copper metal evaporation rate 0.05 Å / s until the copper metal deposition thickness on the buffer layer is 90 nm, thus obtaining the wide-bandgap perovskite solar cell with buried interface modification.

[0068] Example 3

[0069] A wide-bandgap perovskite solar cell with a buried interface modification has the same structure and material as in Example 1.

[0070] The wide-bandgap perovskite solar cell with buried interface modification in this embodiment is prepared through the following steps:

[0071] (1) The 25 mm × 25 mm ITO conductive glass was pre-cleaned with ultrapure water and ethanol for 20 min, dried on a warm table, and then treated in a UV-O3 atmosphere for 20 min.

[0072] (2) Spin-coat an ethanol solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid with a mass concentration of 0.8 mg / mL onto a pre-cleaned ITO conductive glass at a spin-coating speed of 3500 rpm for 20 s, and then anneal at 110℃ for 12 min to obtain a hole transport layer.

[0073] (3) Dissolve (Z)-4-fluorobenzamide oxime in isopropanol so that the mass concentration of (Z)-4-fluorobenzamide oxime in isopropanol is 2 mg / mL to obtain the buried interface treatment solution.

[0074] (4) Spin-coating the buried interface treatment solution onto the cooled hole transport layer surface at a spin coating speed of 4500 rpm for 30 s, followed by annealing at 70℃ for 6 min to obtain the buried interface modification layer.

[0075] (5) CsI, FAI, PbBr2, and PbI2 are arranged according to Cs 0.2 FA 0.8 Pb(I 0.6 Br 0.4 Weigh the proportions from 3 and dissolve them in a mixed solution of dimethylformamide and dimethyl sulfoxide in a volume ratio of 3:1 to obtain component Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3 1.77 eV wide-bandgap perovskite precursor solution;

[0076] (6) A wide-bandgap perovskite precursor solution was dropped onto the surface of the buried interface modification layer. The first spin coating was performed at a spin coating speed of 600 rpm for 3 s, and the second spin coating was performed at a spin coating speed of 4000 rpm for 50 s. Diethyl carbonate was dropped on the 20th s of the second spin coating. After the spin coating was completed, the layer was placed at 70℃ for the first annealing for 3 min, and then placed at 110℃ for the second annealing for 6 min to obtain a wide-bandgap perovskite absorption layer.

[0077] (7) Dissolve 1,3-diaminopropane dihydroiodate in isopropanol to make the mass concentration of 1,3-diaminopropane dihydroiodate 2 mg / mL to obtain the post-interface treatment solution.

[0078] (8) The post-interface treatment solution was spin-coated onto the surface of the wide-bandgap perovskite absorber layer at a spin-coating speed of 4000 rpm for 40 s, and then annealed at 110℃ for 6 min to obtain the post-interface modification layer.

[0079] (9) Heating C using thermal evaporation method 60 When the temperature reaches 530℃, C 60 The evaporation rate is 0.2 Å / s until C 60 An electron transport layer with a deposition thickness of 25 nm was obtained on the back interface modification layer.

[0080] (10) 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was heated to 100°C using atomic deposition, so that the evaporation rate of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was 0.2 Å / s, until the deposition thickness of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline on the electron transport layer was 6 nm, thus obtaining a buffer layer;

[0081] (11) The copper metal is heated by thermal evaporation to make the copper metal evaporation rate 0.2 Å / s until the copper metal deposition thickness on the buffer layer is 110 nm, thus obtaining the wide-bandgap perovskite solar cell with buried interface modification.

[0082] Comparative Example 1

[0083] A wide-bandgap perovskite solar cell includes, from bottom to top, a conductive substrate made of ITO conductive glass, a hole transport layer made of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate, and a Cs-based layer. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 The wide-bandgap perovskite absorber layer of 3, the back interface modification layer made of 1,3-diaminopropane dihydroiodate, and the material of C 60 The electron transport layer, the buffer layer made of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and the metal electrode layer made of copper metal.

[0084] The wide-bandgap perovskite solar cell in this comparative example was prepared through the following steps:

[0085] (1) The 25 mm × 25 mm ITO conductive glass was pre-cleaned with ultrapure water and ethanol for 20 min, dried on a warm table, and then treated in a UV-O3 atmosphere for 20 min.

[0086] (2) Spin-coat an ethanol solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid with a mass concentration of 0.5 mg / mL onto a pre-cleaned ITO conductive glass at a spin-coating speed of 3000 rpm for 20 s, and then anneal at 100℃ for 10 min to obtain a hole transport layer.

[0087] (3) CsI, FAI, PbBr2, and PbI2 are arranged according to Cs 0.2 FA 0.8 Pb(I 0.6 Br 0.4 Weigh the proportions from 3 and dissolve them in a mixed solution of dimethylformamide and dimethyl sulfoxide in a volume ratio of 3:1 to obtain component Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3 1.77 eV wide-bandgap perovskite precursor solution;

[0088] (4) A wide-bandgap perovskite precursor solution was dropped onto the surface of the hole transport layer. The first spin coating was performed at a spin coating speed of 500 rpm for 2 s, and the second spin coating was performed at a spin coating speed of 4000 rpm for 40 s. Diethyl carbonate was dropped on the 20th s of the second spin coating. After the spin coating was completed, the layer was placed at 60℃ for the first annealing for 2 min, and then placed at 100℃ for the second annealing for 5 min to obtain a wide-bandgap perovskite absorption layer.

[0089] (5) Dissolve 1,3-diaminopropane dihydroiodate in isopropanol to make the mass concentration of 1,3-diaminopropane dihydroiodate 1 mg / mL to obtain the post-interface treatment solution.

[0090] (6) The post-interface treatment solution was spin-coated onto the surface of the wide-bandgap perovskite absorber layer at a spin-coating speed of 3000 rpm for 30 s, and then annealed at 100℃ for 5 min to obtain the post-interface modification layer.

[0091] (7) Heating C using thermal evaporation method 60 When the temperature reaches 530℃, C 60 The evaporation rate is 0.1 Å / s until C 60 An electron transport layer with a deposition thickness of 20 nm was obtained on the back interface modification layer.

[0092] (8) 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline was heated to 100°C using atomic deposition, so that the evaporation rate of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was 0.1 Å / s, until the deposition thickness of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline on the electron transport layer was 5 nm, thus obtaining a buffer layer;

[0093] (9) Heat the copper metal using the thermal evaporation method to make the copper metal evaporation rate 0.1 Å / s until the copper metal deposition thickness on the buffer layer is 100 nm, thus obtaining a wide-bandgap perovskite solar cell.

[0094] Experimental Example

[0095] The wide-bandgap perovskite solar cells prepared in Example 1 and Comparative Example 1 were subjected to... JV The curve test was conducted using the following method: In a glove box filled with nitrogen, a Keysight B2901A source meter was used at AM 1.5G (100 mW cm⁻¹). −2 The light intensity was measured under a light source (Enlitech, SS-F5); the light intensity was calibrated by a silicon reference cell (SRC-00205, Enlitech). JV The measured scan rate was 100 mV·s -1The delay time is 50 ms, and the voltage step size is 10 mV; the effective area of ​​all devices is 0.0576 cm². 2 Test results are as follows Figures 2-3 As shown.

[0096] pass Figure 2 It can be seen that the wide-bandgap perovskite solar cell with buried interface modification prepared in Example 1 of this invention... V OC The significant improvement is mainly due to a marked reduction in nonradiative recombination at the buried interface of the wide-bandgap perovskite, resulting in fewer interface defects and improved quality. This was demonstrated by testing the light intensity correlation between Example 1 and Comparative Example 1. V OC ( Figure 3 As can be seen, the ideal factor n of the wide-bandgap perovskite solar cells prepared in Example 1 and Comparative Example 1 are 1.59 and 1.81, respectively; this shows that the wide-bandgap perovskite solar cells with buried interface modification prepared in this invention have improved in terms of non-radiative loss and charge transfer loss.

[0097] 2. The wide-bandgap perovskite solar cells prepared in Example 1 and Comparative Example 1 were subjected to EQE curve testing. Specifically, the spectral response was recorded using a solar cell quantum efficiency measurement system (QE-R, Enlitech) under monochromatic light from 300 nm to 800 nm in 10 nm increments and a chopping frequency of 210 Hz. The results are as follows: Figure 4 As shown.

[0098] from Figure 4 As can be seen from the above, the spectral response of the wide-bandgap perovskite solar cell with buried interface modification prepared in Example 1 of this invention is better than that of the comparative example. This is undoubtedly due to the superior short-circuit current density. J SC The main reason for the increase is that the increase in short-circuit current density indicates that the battery has a high photoelectric conversion efficiency.

[0099] The present invention has been described according to the above embodiments. It should be understood that the above embodiments do not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent transformation fall within the scope of the present invention.

Claims

1. A wide-bandgap perovskite solar cell with a buried interface modification, characterized in that, The wide-bandgap perovskite solar cell with buried interface modification includes a conductive substrate, a hole transport layer, a buried interface modification layer, a wide-bandgap perovskite absorber layer, a back interface modification layer, an electron transport layer, a buffer layer, and a metal electrode layer stacked sequentially from bottom to top. The material of the embedded interface modification layer is an amide oxime compound.

2. The wide-bandgap perovskite solar cell with buried interface modification as described in claim 1, characterized in that, The amamide oxime compound is (Z)-4-fluorobenzamide oxime.

3. The wide-bandgap perovskite solar cell with buried interface modification as described in claim 1, characterized in that, The conductive substrate is made of ITO conductive glass; the hole transport layer is made of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate; and the wide-bandgap perovskite absorber layer is made of Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3; the material of the post-interface modification layer is 1,3-diaminopropane dihydroiodate; the material of the electron transport layer is C 60 The buffer layer is made of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; the metal electrode layer is made of copper.

4. The method for preparing a wide-bandgap perovskite solar cell with buried interface modification according to any one of claims 1 to 3, characterized in that, Includes the following steps: (1) A hole transport layer solution is spin-coated onto a pre-cleaned conductive substrate and annealed to obtain a hole transport layer; the hole transport layer solution is an organic solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid; (2) Dissolve the amyloxime compound in an organic solvent to obtain a substrate interface treatment solution; (3) Spin-coating the buried interface treatment solution onto the hole transport layer and annealing it to obtain the buried interface modification layer. (4) A wide-bandgap perovskite precursor solution was spin-coated onto the subsurface interface modification layer using an anti-solvent method and then annealed to obtain a wide-bandgap perovskite absorber layer; the wide-bandgap perovskite precursor solution was Cs. 0.2 FA 0.8 Pb(I 0.6 Br 0.4 )3 organic solutions; (5) Spin-coating the post-interface treatment solution onto the wide-bandgap perovskite absorber layer and annealing it to obtain the post-interface modified layer; the post-interface treatment solution is an organic solution of 1,3-diaminopropane dihydroiodate. (6) An electron transport layer, a buffer layer and a metal electrode layer are sequentially deposited on the surface of the back interface modification layer by thermal evaporation to obtain the desired result.

5. The method for preparing a wide-bandgap perovskite solar cell with buried interface modification as described in claim 4, characterized in that, In step (1), the organic solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid is an ethanolic solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid with a mass concentration of 0.3~0.8 mg / mL; in step (1), the spin coating speed is 2500~3500 rpm and the time is 10~20 s; the annealing temperature is 90~110℃ and the time is 8~12 min.

6. The method for preparing a wide-bandgap perovskite solar cell with buried interface modification as described in claim 4, characterized in that, The organic solvent in step (2) is isopropanol; the mass concentration of the buried interface treatment solution is 0.5~2 mg / mL.

7. The method for preparing a wide-bandgap perovskite solar cell with buried interface modification as described in claim 4, characterized in that, In step (3), the spin coating speed is 3500~4500 rpm and the time is 20~30 s; the annealing temperature is 50~70℃ and the time is 4~6 min.

8. The method for preparing a wide-bandgap perovskite solar cell with buried interface modification as described in claim 4, characterized in that, Step (4) includes the following steps: a wide-bandgap perovskite precursor solution is dropped onto the buried interface modification layer and spin-coated at 400-600 rpm for 1-3 s, followed by a second spin-coating at 3000-4000 rpm for 30-50 s, and diethyl carbonate is dropped on at the 15-20 s of the second spin-coating; after spin-coating, the mixture is placed at 50-70℃ for a first annealing for 1-3 min, and then placed at 90-110℃ for a second annealing for 4-6 min.

9. The method for preparing a wide-bandgap perovskite solar cell with buried interface modification as described in claim 4, characterized in that, In step (5), the organic solution of 1,3-diaminopropane dihydroiodate is an isopropanol solution of 1,3-diaminopropane dihydroiodate with a mass concentration of 0.5~2 mg / mL; in step (5), the spin coating speed is 2000~4000 rpm and the time is 20~40 s; the annealing temperature is 90~110℃ and the time is 4~6 min.

10. The method for preparing a wide-bandgap perovskite solar cell with buried interface modification as described in claim 4, characterized in that, In step (6), the deposition rate is 0.05~0.2 Å / s; the electron transport layer deposition thickness is 15~25 nm, the buffer layer deposition thickness is 4~6 nm, and the metal electrode layer deposition thickness is 90~110 nm.

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