Composite hole transport layer, preparation method and perovskite solar cell
Patent Information
- Application Number
- CN202610714398.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-22
- Publication Date
- 2026-09-22
AI Technical Summary
[0006]本发明的目的在于提供一种复合空穴传输层、制备方法和钙钛矿太阳能电池，解决现有技术中存在的无法同时协调浸润性、钙钛矿与Me-4PACz的直接接触以及提高器件稳定性的问题
本发明提供的一种复合空穴传输层、制备方法和钙钛矿太阳能电池，将氧化铝纳米颗粒和Me-4PACz分子共混于一层空穴传输层中，可实现一次涂布，避免了分层涂布；由于氧化铝纳米颗粒表面富含羟基，具有亲水性，其嵌入Me-4PACz分子层后，能有效降低复合空穴传输层的表面接触角，实现浸润性的提升；同时氧化铝纳米颗粒的引入，增加了表面粗糙度，有利于后续钙钛矿的成核和结晶；上述共混策略，允许部分的Me-4PACz分子直接暴露于复合空穴传输层表面，在氧化铝纳米颗粒未覆盖的区域，钙钛矿与Me-4PACz保持直接接触，Me-4PACz分子的π环能够钝化钙钛矿底部未配位铅离子缺陷，即钝化Vpb2+深能级陷阱，从而减少界面非辐射复合，提升后续制备的钙钛矿太阳能电池的开路电压，解决了钙钛矿与Me-4PACz的直接接触问题；氧化铝纳米颗粒作为间隔物嵌入Me-4PACz分子层中，可形成增厚的偶极层，优化能级排列，增强界面偶极强度，促进空穴提取，同时避免了对原子层沉积昂贵设备的依赖；氧化铝纳米颗粒具有碘捕获能力，可抑制钙钛矿分解产生的卤化物离子向空穴传输界面的迁移，能够减轻有害卤化物离子从钙钛矿吸收层向空穴传输界面的迁移，同时减轻环境应力的影响，此外，氧化铝纳米颗粒的存在有助于形成稳定的界面结构，显著提升器件的长期稳定性；综上所述，本发明提供了一种既能一步解决浸润性问题、又能保持钙钛矿与Me-4PACz的直接接触、同时还能提升器件稳定性的空穴传输层。
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Abstract
Description
Technical Field
[0001] This invention relates to a composite hole transport layer, its preparation method, and a perovskite solar cell, belonging to the field of perovskite solar cell technology. Background Technology
[0002] Inverted perovskite solar cells have become the mainstream technology for the industrialization of perovskite photovoltaics due to their advantages of high efficiency and stability, ease of mass production, and tandem stacking. In recent years, thanks to the development of self-assembled monolayer materials as hole transport layers, the photoelectric conversion efficiency of inverted perovskite solar cells has achieved significant breakthroughs. Among them, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, or Me-4PACz, has become one of the most promising hole transport layer materials due to its suitable energy level arrangement, good interface passivation ability, and excellent matching with perovskite materials.
[0003] However, Me-4PACz still faces two major challenges in practical applications: First, the uncontrolled self-assembly state of Me-4PACz molecules on the substrate and their uneven distribution at the molecular scale lead to interfacial charge transport losses. Second, Me-4PACz exhibits poor surface wettability to perovskite precursor solutions, resulting in numerous micropores and imperfect crystallization at the buried interface. This leads to severe interfacial recombination caused by numerous buried interface defects, which is a significant factor limiting further improvements in the efficiency of inverted perovskite solar cells. Especially when using scalable processes such as slot coating to prepare perovskite layers on large-area substrates, the poor wetting problem caused by the hydrophobicity of the Me-4PACz surface is further amplified, resulting in severe defects such as macroscopic streaks and thin-film pores.
[0004] To address the aforementioned issues, existing technologies primarily employ two approaches: First, depositing an additional hydrophilic material as an interface modification layer on the Me-4PACz surface. For instance, Professor Liang Guangxing's research group at Shenzhen University, in collaboration with Professor Chen Wei at Huazhong University of Science and Technology, reported introducing alumina nanoparticles as an interface modifier for the hole transport layer of Me-4PACz. This enhances surface wettability, promoting the growth of high-quality perovskite films and improving the device's environmental stability. However, this strategy involves step-by-step coating, increasing the process steps, and the introduction of the extra layer may hinder direct contact between the perovskite and Me-4PACz, affecting charge transport efficiency. Second, in-situ modification of the Me-4PACz layer using co-adsorbents or additives. A team led by Chen Wei and Liu Zonghao from Huazhong University of Science and Technology reported a self-assembly monomolecular hybridization strategy at a buried interface in the journal *Nature*. This strategy involves introducing a triphenylamine monomer (NA) with a large π-conjugated group and symmetrical polycarboxyl groups into the Me-4PACz precursor solution. The strong π-π interaction between NA and Me-4PACz induces a more uniform distribution of Me-4PACz molecules at the nanoscale. Simultaneously, the presence of the polycarboxyl-containing NA monomer effectively improves the wettability of the perovskite solution on Me-4PACz, eliminating nanopores at the buried interface. However, NA, as a small organic molecule, does not possess good interfacial passivation capabilities or encapsulation effects.
[0005] In summary, there is an urgent need to develop a hole transport layer that can solve the wettability problem in one step, maintain direct contact between perovskite and Me-4PACz, and improve device stability. Summary of the Invention
[0006] The purpose of this invention is to provide a composite hole transport layer, a preparation method, and a perovskite solar cell, which solves the problems in the prior art of simultaneously coordinating wettability, direct contact between perovskite and Me-4PACz, and improving device stability.
[0007] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a composite hole transport layer comprising alumina nanoparticles and Me-4PACz, wherein the mass ratio of alumina nanoparticles to Me-4PACz is 1:(10~100).
[0008] Furthermore, the mass ratio of the alumina nanoparticles to the Me-4PACz is 1:(20~50).
[0009] Furthermore, the alumina nanoparticles have a particle size of 5~50 nm.
[0010] Furthermore, the thickness of the composite hole transport layer is 5~15nm, and the thickness non-uniformity in the 245mm×245mm region is less than 5%.
[0011] In a second aspect, the present invention provides a method for preparing the composite hole transport layer as described in any one of the first aspects, comprising: Me-4PACz was dissolved in an organic solvent to prepare a basic Me-4PACz solution; Alumina nanoparticles were dispersed in an organic solvent and ultrasonically treated to prepare an alumina nanoparticle stock solution. Me-4PACz base solution and alumina nanoparticle stock solution were mixed and ultrasonically treated to obtain composite hole transport layer solution; A composite hole transport layer solution is coated onto a conductive substrate and then annealed to form a composite hole transport layer.
[0012] Furthermore, in the composite hole transport layer solution, the concentration of the alumina nanoparticles is 0.005~0.05 mg / mL, and the concentration of Me-4PACz is 0.3~1.0 mg / mL.
[0013] Furthermore, the organic solvent is an alcohol solvent.
[0014] Furthermore, the composite hole transport layer solution is coated onto the conductive substrate using a slot coating process, and the coating is performed under the following process parameter constraints: The gap between the coating head and the conductive substrate is 150~300μm, the coating speed is 5~20mm / s, the liquid supply rate is 0.2~1.0mL / min, and the coating speed is 8~12mm / s.
[0015] Furthermore, the surface water contact angle at each point on the conductive substrate surface is less than 30°, and the non-uniformity of the surface water contact angle is within ±3°.
[0016] Thirdly, the present invention provides a perovskite solar cell, comprising, from bottom to top, a conductive substrate, a composite hole transport layer as described in any one of the first aspects, a perovskite absorber layer, an electron transport layer, a hole blocking layer, and an electrode.
[0017] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention provides a composite hole transport layer, its preparation method, and a perovskite solar cell. Alumina nanoparticles and Me-4PACz molecules are co-coated into a single hole transport layer, enabling one-step coating and avoiding layered coating. Because the alumina nanoparticles are rich in hydroxyl groups and possess hydrophilicity, their embedding into the Me-4PACz molecular layer effectively reduces the surface contact angle of the composite hole transport layer, improving wettability. Simultaneously, the introduction of alumina nanoparticles increases surface roughness, which is beneficial for subsequent perovskite nucleation and crystallization. This co-coating strategy allows some Me-4PACz molecules to be directly exposed on the surface of the composite hole transport layer. In areas not covered by alumina nanoparticles, the perovskite and Me-4PACz maintain direct contact. The π-ring of the Me-4PACz molecules can passivate the uncoordinated lead ion defects at the bottom of the perovskite, i.e., passivate Vpb. 2+ Deep-level traps reduce non-radiative recombination at the interface, improving the open-circuit voltage of the subsequently fabricated perovskite solar cells and solving the problem of direct contact between perovskite and Me-4PACz. Alumina nanoparticles, acting as spacers embedded in the Me-4PACz molecular layer, form a thickened dipole layer, optimizing energy level arrangement, enhancing interfacial dipole strength, and promoting hole extraction, while avoiding dependence on expensive atomic layer deposition equipment. Alumina nanoparticles possess iodine-trapping capabilities, inhibiting the migration of halide ions generated from perovskite decomposition to the hole transport interface, mitigating the migration of harmful halide ions from the perovskite absorber layer to the hole transport interface, and reducing the impact of environmental stress. Furthermore, the presence of alumina nanoparticles helps form a stable interfacial structure, significantly improving the long-term stability of the device. In summary, this invention provides a hole transport layer that solves the wettability problem in one step, maintains direct contact between perovskite and Me-4PACz, and improves device stability. Attached Figure Description
[0018] Figure 1 This is a flowchart of a method for preparing a composite hole transport layer according to an embodiment of the present invention; Figure 2 This is a comparative schematic diagram of the surface water contact angles of the composite hole transport layer provided in Example 1 and the pure Me-4PACz layer provided in Comparative Example 1. Figure 3 This is a graph showing the change of short-circuit current density with open-circuit voltage for the perovskite solar cell provided in this embodiment of the invention. Detailed Implementation
[0019] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.
[0020] To verify the beneficial effects of the hole transport layer provided by the present invention, the following embodiments are provided, in which different hole transport layers are prepared in perovskite solar cells to verify the beneficial effects.
[0021] Example 1
[0022] This embodiment uses the following method to prepare a perovskite solar cell: Step S1: Preparation of conductive substrate.
[0023] A 245 mm × 245 mm ITO conductive thin film glass was used as the conductive substrate. First, P1 lines were drawn on the conductive substrate, with a sub-cell width of 0.5 cm. The substrate was then cleaned with detergent and deionized water for 15 min each, dried with nitrogen, and treated with UV-O3 for 15 min.
[0024] Sputtering NiO onto the cleaned conductive substrate x The substrate is 18 nm thick and is prepared by acid washing and plasma treatment after sputtering.
[0025] Step S2: Prepare the composite hole transport layer solution. Follow the instructions as follows... Figure 1 The process shown in this embodiment involves preparing a composite hole transport layer solution using the following method.
[0026] Me-4PACz was dissolved in anhydrous ethanol to prepare a basic Me-4PACz solution with a concentration of 0.5 mg / mL; Alumina nanoparticles with a particle size of 15 nm were dispersed in an organic solvent and ultrasonically treated for 30 min to prepare a stock solution of alumina nanoparticles with a concentration of 1.0 mg / mL. 48.5 mL of Me-4PACz base solution and 1.5 mL of alumina nanoparticle stock solution were mixed, sonicated for 15 min, and then filtered through a 0.45 μm PTFE filter to obtain the composite hole transport layer solution. The final concentration of alumina nanoparticles in the composite hole transport layer solution was 0.03 mg / mL, and the mass ratio of alumina nanoparticles to Me-4PACz was 1:30. The full name of the PTFE filter is polytetrafluoroethylene needle filter.
[0027] Step S3: Slit coating to prepare a composite hole transport layer.
[0028] The parameters for slit coating are set as follows: coating head width is 240 mm, slightly smaller than the width of the conductive substrate; the gap between the coating head and the conductive substrate is 200 μm; the coating speed is 10 mm / s; the liquid supply rate is 0.4 mL / min; and the coating temperature is room temperature.
[0029] The conductive substrate obtained in step S1 is fixed on the vacuum chuck of the slit coating machine, and the coating program is started to uniformly coat the composite hole transport layer solution on the surface of the conductive substrate to form a continuous liquid film.
[0030] Immediately transfer it to a large-area hot plate and anneal at 100°C for 10 minutes to form a composite hole transport layer.
[0031] According to multi-point ellipsometer testing, the average thickness of the composite hole transport layer is about 8 nm, and the thickness non-uniformity is less than 5%.
[0032] Step S4: Slit coating to prepare a perovskite absorber layer.
[0033] Preparation of perovskite precursor solution: Preparation of Cs 0.05 FA 0.95 The PbI3 solution, with a concentration of 1.4 M, was prepared by mixing DMF and DMSO in a volume ratio of 4:1. After stirring at room temperature for 2 hours, the solution was filtered for later use. The volume of the perovskite precursor solution was 30 mL.
[0034] The parameters for slit coating are set as follows: coating head width is 240 mm, slightly smaller than the width of the conductive substrate; the gap between the coating head and the conductive substrate is 150 μm; the coating speed is 8 mm / s; the liquid supply rate is 0.4 mL / min; the coating speed is 10 mm / s; and the coating temperature is room temperature.
[0035] Coating process: The perovskite precursor solution is directly slit-coated onto a conductive substrate with a pre-coated composite hole transport layer. Thanks to the improved wettability from alumina doping, the perovskite precursor solution spreads rapidly to form a uniform liquid film without pore formation.
[0036] Annealing treatment: The wet film is first annealed at 50℃ for 2 min, and then annealed at 130℃ for 10 min to form a black perovskite film, which is the perovskite absorber layer. The film has a uniform and bright appearance, with no defects visible to the naked eye.
[0037] Step S5: Subsequent processes.
[0038] After depositing an electron transport layer on the perovskite absorber layer, an ALD-SnO2 layer is deposited as a hole blocking layer using atomic deposition. Finally, ITO and Cu metals are deposited on the surface of the hole blocking layer using vacuum evaporation. Finally, P3 scribing is performed to obtain the perovskite solar cell.
[0039] Example 2
[0040] The difference between this embodiment and Embodiment 1 is that the mass ratio of alumina nanoparticles to Me-4PACz in step S2 is 1:100, and the concentration of alumina nanoparticles in the final composite hole transport layer solution is 0.005 mg / mL.
[0041] Example 3
[0042] The difference between this embodiment and Embodiment 1 is that the mass ratio of alumina nanoparticles to Me-4PACz in step S2 is 1:50, and the concentration of alumina nanoparticles in the final composite hole transport layer solution is 0.01 mg / mL.
[0043] Example 4
[0044] The difference between this embodiment and Embodiment 1 is that the mass ratio of alumina nanoparticles to Me-4PACz in step S2 is 1:20, and the concentration of alumina nanoparticles in the final composite hole transport layer solution is 0.025 mg / mL.
[0045] Example 5
[0046] The difference between this embodiment and Embodiment 1 is that the mass ratio of alumina nanoparticles to Me-4PACz in step S2 is 1:10, and the concentration of alumina nanoparticles in the final composite hole transport layer solution is 0.05 mg / mL.
[0047] Example 6
[0048] The difference between this embodiment and Embodiment 1 is that the particle size of the alumina nanoparticles in step S2 is 5 nm.
[0049] Example 7
[0050] The difference between this embodiment and Embodiment 1 is that the particle size of the alumina nanoparticles in step S2 is 10 nm.
[0051] Example 8
[0052] The difference between this embodiment and Embodiment 1 is that the particle size of the alumina nanoparticles in step S2 is 20 nm.
[0053] Example 9
[0054] The difference between this embodiment and Embodiment 1 is that the particle size of the alumina nanoparticles in step S2 is 30 nm.
[0055] Example 10
[0056] The difference between this embodiment and Embodiment 1 is that the particle size of the alumina nanoparticles in step S2 is 50 nm.
[0057] Example 11
[0058] The difference between this embodiment and Embodiment 1 is that the coating speed in step S3 is set to 5 mm / s.
[0059] Example 12
[0060] The difference between this embodiment and Embodiment 1 is that the coating speed in step S3 is set to 8 mm / s.
[0061] Example 13
[0062] The difference between this embodiment and Embodiment 1 is that the coating speed in step S3 is set to 12 mm / s.
[0063] Example 14
[0064] The difference between this embodiment and Embodiment 1 is that the coating speed in step S3 is set to 15 mm / s.
[0065] Example 15
[0066] The difference between this embodiment and Embodiment 1 is that the coating speed in step S3 is set to 20 mm / s.
[0067] Comparative Example 1 The difference between this comparative example and Example 1 is that the composite hole transport layer solution in step S2 is replaced with the Me-4PACz base solution in Example 1, i.e., without alumina nanoparticles.
[0068] Comparative Example 2 The difference between this comparative example and Example 1 is that the composite hole transport layer solution in step S2 is replaced with two solutions applied in layers. The two solutions are the Me-4PACz base solution in Example 1 and the alumina nanoparticle reserve solution in Example 1. First, a layer of Me-4PACz base solution is applied and annealed, then a layer of alumina nanoparticle reserve solution is applied, and after annealing again, an alumina / Me-4PACz bilayer structure is formed as the hole transport layer.
[0069] Comparative Example 3 The difference between this comparative example and Example 1 is that the composite hole transport layer solution in step S2 is replaced with a two-layer coating of solutions: the Me-4PACz base solution from Example 1 and the alumina nanoparticle reservoir solution from Example 1. First, a layer of the Me-4PACz base solution is coated and annealed, then a layer of the alumina nanoparticle reservoir solution is deposited via ALD, followed by another annealing to form an alumina / Me-4PACz bilayer structure as the hole transport layer. The deposition parameters are as follows: temperature 100℃, TMA and water as precursors, 5 cycles, thickness approximately 0.5 nm.
[0070] In the following performance tests, the surface water contact angle and surface water contact angle non-uniformity were tested using a contact angle measuring instrument; the open circuit voltage, short circuit current, fill factor, and photoelectric conversion efficiency were obtained through current-voltage characteristic testing; and the thickness and thickness non-uniformity were measured using the elliptic polarization method.
[0071] By comparing Examples 1, 2, 3, 4, 5, Comparative Examples 1, 2, and 3, the effect of the mass ratio of alumina nanoparticles to Me-4PACz on wettability and device performance was studied.
[0072] In the above embodiments and comparative examples, after the hole transport layer was prepared, its surface water contact angle and surface water contact angle non-uniformity were tested by a contact angle measuring instrument. For the surface water contact angle, 9 points were selected for each sample and the average value was taken. The test results are shown in Table 1.
[0073] Table 1 - Comparison of Surface Water Contact Angle and Its Non-uniformity
[0074] In Table 1, the alumina doping ratio refers to the mass ratio of alumina nanoparticles to Me-4PACz.
[0075] like Figure 2 As shown, in Example 1, the mass ratio of alumina nanoparticles to Me-4PACz was 1:30 to prepare a composite hole transport layer. Compared with Comparative Example 1, the surface water contact angle decreased from 78° to 24°. Furthermore, as shown in Table 1, the surface water contact angle non-uniformity of Example 1 was only ±2°, demonstrating a significant improvement in wettability. Table 1 also shows that increasing the alumina doping ratio initially leads to a decrease in the surface water contact angle, but excessively high alumina doping ratios result in decreased film uniformity. While Comparative Examples 2 and 3 also achieved low surface water contact angles, their process complexity increased significantly.
[0076] In the above embodiments and comparative examples, after the perovskite solar cells were fabricated, their Voc, Isc, FF, and PCE were tested under standard AM 1.5G illumination. The effective area of the perovskite solar cells was 1 cm². 2 Voc is the open-circuit voltage, Isc is the short-circuit current, FF is the fill factor, and PCE is the photoelectric conversion efficiency. All of the above battery performance parameters were obtained through current-voltage characteristic testing, and the test results are shown in Table 2. The data for Example 1 are as follows: Figure 3 As shown.
[0077] Table 2 - Battery Performance Comparison Table
[0078] By comparing Examples 1, 6, 7, 8, 9 and 10, the influence of alumina nanoparticles on device performance was studied. The surface water contact angle and photoelectric conversion efficiency of the composite hole transport layer in each of the above examples were tested, and the test results are shown in Table 3.
[0079] Table 3 - Comparison of Surface Water Contact Angle and Photoelectric Conversion Efficiency
[0080] According to the data shown in Table 3, the optimal particle size for alumina nanoparticles is 10-20 nm, with 15 nm showing the best effect. If the particle size is too small, they are prone to agglomeration, while if the particle size is too large, they will not be densely packed, resulting in a decrease in the effect of improving wettability.
[0081] By comparing Examples 1, 11, 12, 13, 14 and 15, the influence of coating speed on the thickness and thickness non-uniformity of the composite hole transport layer was studied. The average thickness and thickness non-uniformity of the composite hole transport layer in each of the above examples were tested, and the test results are shown in Table 4.
[0082] Table 4 - Comparison of Average Thickness and Thickness Inhomogeneity
[0083] According to the data in Table 4, a coating speed of 8-12 mm / s can achieve good film uniformity, with 10 mm / s being the optimal speed.
[0084] Based on the above embodiments, comparative examples, and corresponding data, the preferred parameter settings range of this invention are as follows: the particle size of alumina nanoparticles is 10~20nm, preferably 15nm; the alumina doping ratio is 1:50 to 1:20 (preferably 1:30) of alumina nanoparticles to Me-4PACz; the concentration of alumina nanoparticles in the mixture is 0.01~0.04mg / mL; and the coating speed is 8~12mm / s. The composite hole transport layer prepared within this process range can effectively solve the non-wetting problem on the Me-4PACz surface, ensuring high-quality preparation of slit-coated perovskite films over large areas. It can also optimize energy level matching by enhancing the interfacial dipole effect, and improve device stability by utilizing the iodine trapping ability of alumina nanoparticles, thus achieving high-efficiency, high-uniformity, and high-stability preparation of large-area perovskite solar cells.
[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles 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 composite hole transport layer, characterized in that, It includes alumina nanoparticles and Me-4PACz, with a mass ratio of alumina nanoparticles to Me-4PACz of 1:(10~100).
2. The composite hole transport layer according to claim 1, characterized in that, The mass ratio of the alumina nanoparticles to the Me-4PACz is 1:(20~50).
3. The composite hole transport layer according to claim 1, characterized in that, The alumina nanoparticles have a particle size of 5~50 nm.
4. The composite hole transport layer according to claim 1, characterized in that, The thickness of the composite hole transport layer is 5~15nm, and the thickness non-uniformity in the 245mm×245mm region is less than 5%.
5. The method for preparing the composite hole transport layer according to any one of claims 1 to 4, characterized in that, include: Me-4PACz was dissolved in an organic solvent to prepare a basic Me-4PACz solution; Alumina nanoparticles were dispersed in an organic solvent and ultrasonically treated to prepare an alumina nanoparticle stock solution. Me-4PACz base solution and alumina nanoparticle stock solution were mixed and ultrasonically treated to obtain composite hole transport layer solution; A composite hole transport layer solution is coated onto a conductive substrate and then annealed to form a composite hole transport layer.
6. The method for preparing the composite hole transport layer according to claim 5, characterized in that, In the composite hole transport layer solution, the concentration of the alumina nanoparticles is 0.005~0.05 mg / mL, and the concentration of Me-4PACz is 0.3~1.0 mg / mL.
7. The method for preparing the composite hole transport layer according to claim 5, characterized in that, The organic solvent is an alcohol solvent.
8. The method for preparing the composite hole transport layer according to claim 5, characterized in that, The composite hole transport layer solution is coated onto a conductive substrate using a slot coating process, and the coating is performed under the following process parameter constraints: The gap between the coating head and the conductive substrate is 150~300μm, the coating speed is 5~20mm / s, the liquid supply rate is 0.2~1.0mL / min, and the coating speed is 8~12mm / s.
9. The method for preparing the composite hole transport layer according to claim 5, characterized in that, The surface water contact angle at all points on the conductive substrate surface is less than 30°, and the non-uniformity of the surface water contact angle is within ±3°.
10. A perovskite solar cell, characterized in that, It includes, from bottom to top, a conductive substrate, a composite hole transport layer as described in any one of claims 1 to 4, a perovskite absorber layer, an electron transport layer, a hole blocking layer, and an electrode.