A perovskite solar cell

Abstract

The present invention belongs to the technical field of novel solar cells and relates to a perovskite solar cell, the structure of which is, from bottom to top, a conductive glass electrode layer (1), an electron transport layer (2), a perovskite layer (3), a hole transport layer (4) and a counter electrode layer (5), wherein the hole transport layer (4) is made of NiO x The nanocrystals are uniformly compounded with organic hole materials without ion doping. The perovskite solar cell of the present invention has the characteristics of high photoelectric conversion efficiency and good stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells and relates to a perovskite solar cell, in particular to an upright perovskite solar cell. Background Art

[0002] Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) have developed rapidly in the past few years. The photoelectric conversion efficiency of perovskite solar cells has increased from an initial 3.8% to 25.7%, making them one of the most promising areas for development in the clean energy industry. The core advantages of perovskite solar cell technology lie in its low cost, ease of preparation, and excellent photoelectric performance. Generally, to achieve high photoelectric conversion efficiency in PSCs, both electron and hole transport layers are required to effectively separate the photogenerated charges absorbed in the perovskite layer and selectively transfer the separated electrons and holes. Furthermore, while improving conversion efficiency, it is also necessary to enhance the tolerance of the perovskite layer and carrier transport materials to external environmental factors such as humidity, light, and heat to ensure the long-term stable operation of PSCs. Therefore, finding an efficient, stable, and low-cost hole transport material is a prerequisite for achieving stable perovskite solar cells.

[0003] Inorganic hole transport materials usually have the advantages of good chemical stability and low cost, and have broad application prospects in perovskite solar cells. x It has the characteristics of controllable energy levels, good stability, low cost and high hole mobility, and is one of the best candidates for highly stable inorganic hole transport materials.

[0004] In the orthographic structure, NiO x The urgent problem to be solved in the hole transport layer is how to improve NiO x To improve the film quality of perovskite surfaces, only a dense, pinhole-free hole transport layer can prevent contact between the electrode and the perovskite, thereby achieving high photoelectric conversion efficiency and good device stability. To this end, a simple and scalable method is urgently needed to improve both hole mobility and the density of the hole transport layer film to enhance the performance of perovskite solar cells. Summary of the Invention

[0005] Based on the above technical problems, the present invention aims to provide a perovskite solar cell, which improves the NiO x Dispersibility in organic solvents, thereby regulating NiO x The film quality of NiO x Efficiency and thermal stability of hole-causing devices.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A perovskite solar cell comprising a hole transport layer (4), wherein the hole transport layer (4) is made of NiO x The nanocrystal is composited with an organic hole material without ion doping. The hole transport layer (4) of the present invention is more suitable for an orthogonal perovskite solar cell, that is, a NIP structure perovskite solar cell.

[0008] In a preferred technical solution of the present invention, the hole transport layer (4) is a single-layer structure with a thickness of 20-120 nm.

[0009] In the preferred technical solution of the present invention, the NiO in the hole transport layer (4) x The mass ratio of nanocrystal to organic hole material is 0.1-5:1. In a more preferred technical solution of the present invention, NiO x The mass ratio of the nanocrystal to the organic hole material is 0.3-3:1.

[0010] In a preferred technical solution of the present invention, the preparation method of the hole transport layer (4) comprises the following steps:

[0011] S1, NiO x The nanocrystals are dispersed in the first organic solvent to prepare NiO with a concentration of 2-40 mg / mL. x dispersion;

[0012] S2, dispersing the non-ion-doped organic hole material in a second organic solvent to prepare an organic hole material dispersion with a concentration of 2-50 mg / mL;

[0013] S3, the NiO obtained in step S1 x The dispersion liquid and the organic hole material dispersion liquid obtained in step S2 are NiO x The nanocrystals and the organic hole material are mixed uniformly at a mass ratio of 0.1-5:1, and then directly coated on the surface of the perovskite layer (3), and dried naturally to obtain the hole transport layer (4).

[0014] In the present invention, NiO x A preparation method of nanocrystals is as follows: nickel stearate is used as a nickel source, lithium stearate is used as a protective agent, octadecanol or oleylamine is used as a dispersant, and octadecene is used as a solvent. 5 mmol of nickel stearate, 2 mmol of lithium stearate, 3 mmol of octadecanol (or oleylamine) and 5 mL of octadecene are mixed and placed in a reactor, mixed and stirred at 80°C in an inert atmosphere for 0.5 h, then heated to 230-270°C and kept warm for 2-4 h. The product is washed with acetone / ethyl acetate mixed solvent and n-hexane / ethanol mixed solvent in turn, and dried in vacuum at 60°C overnight to obtain NiO x Nanocrystals.

[0015] In a more preferred embodiment of the present invention, the first organic solvent and the second organic solvent are each independently selected from one or more of chlorobenzene, 1,2-dichlorobenzene, chloroform, toluene and xylene. In a further preferred embodiment of the present invention, the first organic solvent and the second organic solvent are different.

[0016] In a preferred technical solution of the present invention, the organic hole material is selected from one or more of Spiro-OMeTAD, poly-TPD, copper phthalocyanine (CuPc), nickel phthalocyanine (NiPc), polymer poly (triarylamine, triarylamine) (PTAA) and poly (3-hexylthiophene) (P3HT).

[0017] In a preferred technical solution of the present invention, the structure of the perovskite solar cell comprises, from bottom to top, a conductive glass electrode layer (1), an electron transport layer (2), a perovskite layer (3), a hole transport layer (4) and a counter electrode layer (5), wherein the conductive glass electrode layer (1) is an FTO glass layer or an ITO glass layer.

[0018] In a more preferred technical solution of the present invention, the electron transport layer (2) is selected from PC 61 BM layer, PC 71 One or more of a BM layer, a TiO2 layer, a ZnO layer, a SnO2 layer and a ZnTiO3 (ZTO) layer, and the thickness of the electron transport layer (2) is 10-120 nm.

[0019] In a more preferred technical solution of the present invention, the perovskite in the perovskite layer (3) is a semiconductor compound having an ABX3 structure, wherein A is one or more of an amino group, an amidine group, a guanidine group and a monovalent organic cation of cesium, B is one or more of a metal ion of lead, tin, rubidium, silver, bismuth, silicon and magnesium, and X is one or more of an iodide ion, a chloride ion, a bromide ion, a thiocyanate ion and an acetate ion; the molar percentage of lead ions in B is not less than 80%; and the thickness of the perovskite layer (3) is 300 to 700 nm.

[0020] In a more preferred technical solution of the present invention, the electrode material in the counter electrode layer (5) is a metal electrode material, and the electrode material is selected from one or more of gold, silver, copper and tin, and the thickness of the counter electrode layer (5) is 60-120 nm.

[0021] Beneficial effects of the present invention:

[0022] 1. The present invention improves NiO by using organic hole material doping and mixing with organic solvents.x Improve the dispersibility of NiO in organic solvents x The assembly order is high, and a dense, continuous hole transport layer with high hole mobility (4) is obtained, thereby improving the NiO x Photovoltaic conversion efficiency and thermal stability of solar cells based on hole transport layers;

[0023] 2.NiO x The ligand improves the crystallinity of the undoped organic hole molecules by improving their assembly orientation, which is beneficial to the transmission of holes in the direction of their π-π bonds or on the main chain, thereby improving the hole mobility of the hole transport layer.

[0024] 3. By regulating the energy level of the hole transport layer, the migration of carriers from the hole transport layer (4) to the counter electrode layer (5) can be promoted, the non-radiative recombination at the interface caused by the valence band gap can be reduced, and the photoelectric conversion efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the perovskite solar cell of the present invention.

[0026] Among them, 1 is a conductive glass electrode layer, 2 is an electron transport layer, 3 is a perovskite layer, 4 is a hole transport layer, and 5 is a counter electrode layer.

[0027] Figure 2 This is the structure of the hole transport layer (4) in Comparative Example 2.

[0028] Among them, 41-NiO x Layer, 42 - organic Spiro-OMeTAD layer without ion doping.

[0029] Figure 3 Graphs showing IV reverse scanning of the perovskite solar cells of Example 1 and Comparative Examples 1-3.

[0030] Figure 4 This is a comparison chart of the IV thermal stability of the perovskite solar cells of Example 1 and Comparative Examples 1-3. DETAILED DESCRIPTION

[0031] The following describes the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0032] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for the understanding and reading of those familiar with this technology, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, the terms such as "upper", "inner", "outer", "bottom", "one", "middle", etc. quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content and should be described in advance.

[0033] Example 1

[0034] Please refer to the attached Figure 1 For example, the steps for preparing an inverted perovskite solar cell are as follows:

[0035] Step (A), preparing the electron transport layer (2): preparing a SnO2 precursor solution by spin coating on the cleaned FTO glass (1) using a solution method at a spin coating speed of 3000 rpm, annealing at 150°C for 30 minutes after spin coating, and naturally cooling to obtain a SnO2 electron transport layer (2) with a film thickness of 40 nm on the FTO glass (1).

[0036] Step (B), preparing the perovskite layer (3): spin coating FA with a concentration of 1.3 mol / L on the electron transport layer (2) of step (A) 0.95 Cs 0.05 The PbI3 solution was spin-coated at 5000 rpm for 30 s. Chlorobenzene was added as an anti-solvent at the 15th s. The solution was annealed at 110°C for 60 min and cooled naturally to obtain a perovskite layer (3).

[0037] Step (C) comprises the following steps (C-1) to (C-3),

[0038] Step (C-1), preparation of NiO x Chloroform solution: Weigh 15 mg NiOx and add it to 1 mL chloroform, ultrasonically disperse for 20 minutes to prepare NiO x Chloroform dispersion;

[0039] Step (C-2), preparing a chlorobenzene dispersion of Spiro-OMeTAD: weighing 30 mg of Spiro-OMeTAD, adding it to 1 mL of chlorobenzene, and ultrasonically dispersing it for 20 minutes to prepare a chlorobenzene dispersion of Spiro-OMeTAD;

[0040] Step (C-3), preparing the hole transport layer (4): the above NiO x The chloroform dispersion of the compound was mixed with the chlorobenzene dispersion of Spiro-OMeTAD in a volume ratio of 2:1, and ultrasonicated for 10 minutes to prepare a composite hole transport layer material dispersion. The composite hole transport layer was spin-coated on the perovskite layer (3) using a solution method at a spin coating speed of 2000 rpm and dried naturally to obtain a hole transport layer (4) with a film thickness of 65 nm.

[0041] Step (D), preparing the counter electrode layer (5): evaporating metallic silver on the hole transport layer (4) to obtain the counter electrode layer (5) with a film thickness of 110 nm.

[0042] Thus, an upright perovskite solar cell was obtained, which was recorded as C-1.

[0043] Example 2

[0044] Please refer to the attached Figure 1 For example, the steps for preparing an inverted perovskite solar cell are as follows:

[0045] Step (A), preparing the electron transport layer (2): preparing a SnO2 precursor solution on the cleaned FTO glass (1) by solution spin coating at a spin coating speed of 3000 rpm, annealing at 150°C for 30 minutes after spin coating, and naturally cooling to obtain a SnO2 electron transport layer (2) with a film thickness of 40 nm on the FTO glass (1).

[0046] Step (B), preparing the perovskite layer (3): spin coating FA with a concentration of 1.3 mol / L on the electron transport layer (2) of step (A) 0.95 Cs 0.05 The PbI3 solution was spin-coated at 5000 rpm for 30 s. Chlorobenzene was added as an anti-solvent at the 15th s. The solution was annealed at 110°C for 60 min and cooled naturally to obtain a perovskite layer (3).

[0047] Step (C) comprises the following steps (C-1) to (C-3),

[0048] Step (C-1), prepare NiOx chloroform solution: weigh 20 mg NiO x Dissolve in 1 mL of chloroform and ultrasonically disperse for 20 min to prepare NiO x Chloroform dispersion;

[0049] Step (C-2), preparing a chlorobenzene dispersion of Spiro-OMeTAD: weighing 20 mg of Spiro-OMeTAD and dissolving it in 1 mL of chlorobenzene to prepare a chlorobenzene dispersion of Spiro-OMeTAD;

[0050] Step (C-3), preparing the hole transport layer (4): the above NiO x The chloroform dispersion of Spiro-OMeTAD and the chlorobenzene dispersion of Spiro-OMeTAD were mixed in a volume ratio of 1:1, ultrasonicated for 10 minutes to prepare a composite hole transport layer material dispersion, which was then spin-coated on the perovskite layer (3) using a solution method at a spin coating speed of 2500 rpm and dried naturally to obtain a hole transport layer (4) with a film thickness of 65 nm.

[0051] Step (D), preparing a counter electrode layer (5): evaporating silver on the hole transport layer (4) to obtain a counter electrode layer (5) with a film thickness of 110 nm.

[0052] Thus, a normal perovskite solar cell was obtained, which was recorded as C-2.

[0053] Example 3

[0054] Please refer to the attached Figure 1 For example, the steps for preparing an inverted perovskite solar cell are as follows:

[0055] Step (A), preparing the electron transport layer (2): a ZTO layer is prepared on the cleaned FTO glass (1) by a spray pyrolysis method, the spraying temperature is 475°C, the number of spraying cycles is 3, annealing is performed at 475°C for 60 minutes, and after natural cooling, an ethanol solution of mesoporous titanium dioxide is spin-coated at a speed of 5000 rpm, and annealing is performed at 500°C for 60 minutes to obtain a ZTO / m-TiO2 composite electron transport layer (2) with a film thickness of 80 nm on the FTO glass (1).

[0056] Step (B), preparing the perovskite layer (3): spin coating FA with a concentration of 1.1 mol / L on the electron transport layer (2) of step (A) 0.83 Cs 0.17 The PbI3 solution was spin-coated at 6000 rpm for 30 s. Chlorobenzene was added as an anti-solvent at the 10th s. The solution was annealed at 150° C. for 30 min and cooled naturally to obtain a perovskite layer (3).

[0057] Step (C) comprises the following steps (C-1) to (C-3),

[0058] Step (C-1), preparation of NiO x 1,2-dichlorobenzene solution: weigh 5 mg NiO x Dissolve in 1 mL of 1,2-dichlorobenzene and stir ultrasonically for 20 min to prepare NiO x Dichlorobenzene dispersion;

[0059] Step (C-2), preparing a chlorobenzene / chloroform dispersion of NiPc: weighing 20 mg of NiPc and dissolving it in a mixed solvent consisting of 300 μL of chlorobenzene and 700 μL of chloroform, and stirring ultrasonically for 20 minutes to prepare a chlorobenzene / chloroform dispersion of NiPc;

[0060] Step (C-3), preparing the hole transport layer (4): the above NiO x The dichlorobenzene dispersion of NiPc and the chlorobenzene / chloroform dispersion of NiPc were mixed in a volume ratio of 10:1, ultrasonicated for 10 minutes to prepare a composite hole transport layer material dispersion, which was then spin-coated on the perovskite layer (3) using a solution method at a spin coating speed of 2500 rpm and dried naturally to prepare a hole transport layer (4).

[0061] Step (D), preparing the counter electrode layer (5): evaporating a 20 nm thick gold and 80 nm thick copper composite electrode on the hole transport layer (4) to obtain the counter electrode layer (5).

[0062] Thus, a normal perovskite solar cell was obtained, which was recorded as C-3.

[0063] Example 4

[0064] Please refer to the attached Figure 1 For example, the steps for preparing an inverted perovskite solar cell are as follows:

[0065] Step (A), preparing the electron transport layer (2): a ZnO layer is prepared on the cleaned FTO glass (1) by spray pyrolysis method, the spraying temperature is 500°C, the number of spraying cycles is 5 cycles, annealing is performed at 450°C for 30 minutes, and after natural cooling, an ethanol solution of mesoporous titanium dioxide is spin-coated at a speed of 4000 rpm, and annealing is performed at 475°C for 30 minutes to obtain a ZnO / m-TiO2 composite electron transport layer (2) with a film thickness of 80 nm on the FTO substrate.

[0066] Step (B), preparing a perovskite layer (3): spin coating a FAPbI3 solution with a concentration of 1.2 mol / L on the electron transport layer (2) of step (A), the spin coating condition is 5000 rpm, the spin coating time is 30 s, ether is added as an anti-solvent in the 8th second, annealing at 110° C. for 20 min, and naturally cooling to obtain a perovskite layer (3).

[0067] Step (C) comprises the following steps (C-1) to (C-4),

[0068] Step (C-1), preparation of NiO x Chlorobenzene / chloroform dispersion: weigh 25 mg NiO x Dissolved in a mixed solvent of 200 μL chlorobenzene and 800 μL chloroform, stirred ultrasonically for 20 min, and prepared into NiOx Chlorobenzene / chloroform dispersion;

[0069] Step (C-2), preparing a chloroform dispersion of Spiro-OMeTAD: weighing 20 mg of Spiro-OMeTAD and dissolving it in 1 mL of chloroform, stirring ultrasonically for 20 minutes to prepare a chloroform dispersion of Spiro-OMeTAD;

[0070] Step (C-3), prepare poly-TPD chlorobenzene dispersion: weigh 5 mg NiO x Dissolve in 1 mL of chlorobenzene and stir ultrasonically for 20 min to prepare a poly-TPD chlorobenzene dispersion;

[0071] Step (C-4), preparing the hole transport layer (4): the above NiO x The chlorobenzene / chloroform dispersion of Spiro-OMeTAD, the chloroform dispersion of Spiro-OMeTAD and the chlorobenzene dispersion of poly-TPD were mixed in a volume ratio of 3:1:1, ultrasonicated for 10 minutes to prepare a composite hole transport layer material dispersion, and the solution was spin-coated on the perovskite layer (3) at a spin coating speed of 3000 rpm, and dried naturally to prepare a hole transport layer (4).

[0072] Step (D), preparing the counter electrode layer (5): evaporating a 40 nm thick silver and a 60 nm thick copper composite electrode on the hole transport layer (4) to obtain the counter electrode layer (5).

[0073] Thus, a normal perovskite solar cell was obtained, which was recorded as C-4.

[0074] Example 5

[0075] Please refer to the attached Figure 1 For example, the steps for preparing an inverted perovskite solar cell are as follows:

[0076] Step (A), preparing the electron transport layer (2): a ZnO layer is prepared on the cleaned FTO glass (1) by spray pyrolysis method, the spraying temperature is 500°C, the number of spraying cycles is 5 cycles, annealing is performed at 450°C for 30 minutes, and after natural cooling, a SnO2 aqueous solution is spin-coated at 4000 rpm, annealing is performed at 120°C for 30 minutes, and a ZnO / SnO2 composite electron transport layer (2) with a film thickness of 60 nm is obtained on the FTO substrate.

[0077] Step (B) Preparation of perovskite layer (3): Spin-coat 1.2 mol / L FA on the electron transport layer (2) of step (A). 0.95 MA 0.05The PbI3 solution was spin-coated at 5000 rpm for 30 seconds. Ether was added as an anti-solvent at the 10th second. The solution was annealed at 110°C for 60 minutes and cooled naturally to obtain a perovskite layer (3).

[0078] Step (C), comprising steps (C-1) to (C-3),

[0079] Step (C-1), preparation of NiO x Chloroform solution: weigh 15 mg NiO x Dissolve in 1 mL of chloroform and stir ultrasonically for 20 min to prepare a NiOx chloroform dispersion;

[0080] Step (C-2), preparing a toluene dispersion of PTAA: weighing 10 mg of PTAA and dissolving it in 1 mL of toluene, stirring ultrasonically for 20 minutes to prepare a toluene dispersion of PTAA;

[0081] Step (C-3), preparation of hole transport layer (4): NiO x The chloroform dispersion of the PTAA and the toluene dispersion of the PTAA were mixed in a volume ratio of 1:3, ultrasonicated for 10 minutes, and configured into a composite hole transport layer material dispersion. The composite hole transport layer material dispersion was spin-coated on the perovskite layer (3) using a solution method at a spin coating speed of 2500 rpm, and dried naturally to obtain a hole transport layer (4).

[0082] Step (D), preparing the counter electrode layer (5): evaporating a metal gold electrode with a thickness of 90 nm on the hole transport layer (4) to obtain the counter electrode layer (5).

[0083] Thus, a normal perovskite solar cell was obtained, which was recorded as C-5.

[0084] Comparative Example 1

[0085] In Example 1, step C comprises the following steps (C-1) to (C-2),

[0086] Step (C-1), preparation of NiO x Chloroform solution: weigh 15 mg NiO x Dissolve in 1 mL of chloroform and ultrasonically disperse for 20 min to prepare NiO x of chloroform dispersion.

[0087] Step (C-2), preparing the hole transport layer (4): the above NiO x The chloroform dispersion is spin-coated on the perovskite layer (3) using a solution method at a spin-coating speed of 2000 rpm and dried naturally to obtain a hole transport layer (4) with a film thickness of 40 nm.

[0088] The remaining steps remained unchanged to obtain an upright perovskite solar cell, which was designated as C-6.

[0089] Comparative Example 2

[0090] In Example 1, step (C) comprises the following steps (C-1) to (C-3),

[0091] Step (C-1), preparation of NiO x Chloroform solution: weigh 15 mg NiO x Add to 1 mL of chloroform and disperse by ultrasonic for 20 min to prepare NiOx chloroform dispersion;

[0092] Step (C-2), preparing a chlorobenzene dispersion of Spiro-OMeTAD: weighing 30 mg of Spiro-OMeTAD, adding it to 1 mL of chlorobenzene, and ultrasonically dispersing it for 20 minutes to prepare a chlorobenzene dispersion of Spiro-OMeTAD.

[0093] Step (C-3), preparing the hole transport layer (4): the above NiO x The chloroform dispersion of NiO was spin-coated on the perovskite layer (3) using a solution method at a spin-coating speed of 2500 rpm and dried naturally to obtain NiO x layer; continue to spin-coat the above-mentioned chlorobenzene dispersion of Spiro-OMeTAD using a solution method at a spin coating speed of 3500 rpm and dry naturally to obtain a hole transport layer (4) with a film thickness of 65 nm. The remaining steps remain unchanged to obtain an upright perovskite solar cell, which is recorded as C-7.

[0094] Figure 2 The schematic diagram of the hole transport layer (4) of this comparative example is a double-layer structure, which consists of the lower layer of NiO x layer (41) and an upper Spiro-OMeTAD layer (42).

[0095] Comparative Example 3

[0096] In Example 1, step C comprises the following steps (C-1) to (C-2),

[0097] Step (C-1), preparing a chlorobenzene solution of Spiro-OMeTAD: weighing 72 mg of Spiro-OMeTAD and dissolving it in 1 mL of chlorobenzene, stirring it ultrasonically for 20 minutes to prepare a chlorobenzene dispersion of Spiro-OMeTAD.

[0098] Step (C-2), preparing the hole transport layer (4): spin-coating the above-mentioned chlorobenzene dispersion of Spiro-OMeTAD on the perovskite layer (3) using a solution method at a spin coating speed of 2000 rpm, and drying naturally to obtain a hole transport layer (4) with a film thickness of 80 nm.

[0099] The remaining steps remained unchanged to obtain an upright perovskite solar cell, which was designated as C-8.

[0100] The performance of the upright perovskite solar cells C-1 to C-8 of Examples 1-5 and Comparative Examples 1-3 is shown in Table 1, wherein the photoelectric conversion efficiency retention rate after aging for 1000 hours under the aging condition of 85°C nitrogen atmosphere is shown.

[0101] Table 1

[0102]

[0103]

[0104] Figure 3 The reverse scanning curve data of the upright perovskite solar cell of Example 1 and Comparative Examples 1-3 are shown. x Solar cell devices prepared with hole transport layer (Comparative Example 1), solar cell devices prepared with pure Spiro-OMeTAD hole transport layer (Comparative Example 3) and NiO x +Spiro-OMeTAD double-layer hole transport layer structure prepared solar cell device (Comparative Example 2), based on Spiro-OMeTAD enhanced NiO x The composite single-layer hole transport layer device (Example 1) prepared from the material has higher photoelectric conversion efficiency and thermal stability. Figure 3 The good technical effect that can be obtained from Table 1 is that the device prepared by the hole transport layer prepared by the mixed treatment of organic and inorganic hole materials has better photoelectric conversion efficiency and thermal stability.

[0105] Figure 4 The thermal stability comparison of the upright perovskite solar cells of Example 1 and Comparative Examples 1-3. x The hole transport layer device (Comparative Example 1) was heat-treated at 85°C for 1000 hours under nitrogen conditions, and the photoelectric conversion efficiency was attenuated by 22.7%. The single-layer Spiro-OMeTAD hole transport layer device (Comparative Example 3) was heat-treated at 85°C for 250 hours under nitrogen conditions, and the photoelectric conversion efficiency was attenuated by 99.99%. The organic hole material Spiro-OMeTAD based on the present invention enhanced NiO x The device with hole transport layer (Example 1) showed excellent thermal stability. The photoelectric conversion efficiency decayed by only 9.6% after heat treatment at 85℃ for 1000h in nitrogen atmosphere. x +Spiro-OMeTAD double-layer hole transport layer device (Comparative Example 2), the photoelectric conversion efficiency decayed to nearly 100% after heat treatment at 85℃ for 400h in nitrogen atmosphere. The above results prove that the organic hole transport layer material can enhance the inorganic NiOx Devices using the material as a hole transport layer have higher thermal stability, and coupled with its significant effect in improving efficiency, are conducive to the commercial application and promotion of perovskite solar cells.

Claims

1. A perovskite solar cell, characterized in that: The perovskite solar cell is an upright perovskite solar cell, comprising a hole transport layer (4), wherein the hole transport layer (4) is composed of NiO x Nanocrystals and non-ion-doped organic hole materials are uniformly composited; The preparation method of the hole transport layer (4) comprises the following steps: S1, NiO x The nanocrystals are dispersed in the first organic solvent to prepare NiO with a concentration of 2-40 mg / mL. x dispersion; S2, dispersing the non-ion-doped organic hole material in a second organic solvent to prepare an organic hole material dispersion with a concentration of 2-50 mg / mL; S3, the NiO obtained in step S1 x The dispersion liquid and the organic hole material dispersion liquid obtained in step S2 are NiO x The nanocrystals and the organic hole material are mixed uniformly at a mass ratio of 0.1-5:1, and then directly coated on the surface of the perovskite layer (3), and dried naturally to obtain the hole transport layer (4).

2. The perovskite solar cell according to claim 1, wherein the hole transport layer (4) is a single-layer structure with a thickness of 20-120 nm.

3. The perovskite solar cell according to claim 1, wherein the hole transport layer (4) comprises NiO x The mass ratio of the nanocrystal to the organic hole material is 0.1-5:

1. 4 . The perovskite solar cell according to claim 1 , wherein the first organic solvent and the second organic solvent are each independently selected from one or more of chlorobenzene, 1,2-dichlorobenzene, chloroform, toluene and xylene.

5. The perovskite solar cell according to any one of claims 1 to 3, wherein the organic hole material is selected from one or more of Spiro-OMeTAD, poly-TPD, copper phthalocyanine, nickel phthalocyanine, high molecular weight poly(triarylamine) and poly(3-hexylthiophene).

6. The perovskite solar cell according to any one of claims 1 to 3, wherein the structure of the perovskite solar cell is an upright structure, and comprises, from bottom to top, a conductive glass electrode layer (1), an electron transport layer (2), a perovskite layer (3), a hole transport layer (4) and a counter electrode layer (5).

7. The perovskite solar cell according to claim 6, wherein the electron transport layer (2) is selected from PC 61 BM layer, PC 71 One or more of a BM layer, a TiO2 layer, a ZnO layer, a SnO2 layer and a ZnTiO3 layer, and the thickness of the electron transport layer (2) is 10-120 nm.

8. The perovskite solar cell according to claim 6, wherein the perovskite in the perovskite layer (3) is a semiconductor compound having an ABX3 structure, wherein A is one or more of an amino group, an amidine group, a guanidine group, and a monovalent organic cation of cesium, B is one or more of a metal ion of lead, tin, rubidium, silver, bismuth, silicon, and magnesium, and X is one or more of an iodide ion, a chloride ion, a bromide ion, a thiocyanate group, and an acetate group; The molar percentage of lead ions in B is not less than 80%; The thickness of the perovskite layer (3) is 300-700 nm.

9. The perovskite solar cell according to claim 6, wherein the electrode material in the counter electrode layer (5) is selected from one or more of gold, silver, copper, nickel, tin and ITO, and the thickness of the counter electrode layer (5) is 60-120 nm.

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