Composite hole transport layer for solar cell and preparation method and application thereof

Abstract

The invention provides a composite hole transport layer for a solar cell and a preparation method and application thereof. The composite hole transport layer comprises a first hole transport layer and a second hole transport layer which are stacked in sequence. The first hole transport layer comprises a p-type inorganic semiconductor material layer or a p-type organic semiconductor material layer, and the second hole transport layer comprises a transition metal disulfide layer. The first hole transport layer is modified by taking the transition metal disulfide as a material of the second hole transport layer, so that surface defects of the first hole transport layer can be passivated, the hole transport capability and stability of the first hole transport layer can be improved, the problem of energy level mismatch between the hole transport layer and the perovskite light absorption layer can be improved, and interface contact is optimized. Therefore, the composite hole transport layer can improve the hole transport capability of the device to a greater extent, so that the device has excellent photoelectric performance and stability, and the composite hole transport layer has important significance for promoting the practical application of the perovskite solar cell.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a composite hole transport layer for solar cells, its preparation method, and its application. Background Technology

[0002] With global warming and the increasingly serious energy crisis, improving the traditional energy structure and vigorously developing clean, efficient, and renewable energy has become a consensus among all mankind. Solar energy, as a representative of new energy technologies, is increasing its share in the global energy structure year by year. Solar photovoltaics can be divided into three categories based on its development history: the first generation of solar energy technology represented by silicon; the second generation of thin-film photovoltaic technology mainly based on compound materials; and the third generation of new, high-efficiency solar cell technology. Organic-inorganic hybrid perovskite solar cells, due to their significant advantages such as low cost, high conversion efficiency, and suitability for industrial production, have seen their photoelectric conversion efficiency rapidly rise to 26.1% since their introduction in 2009. It is expected that further cost reductions through improved conversion efficiency will lead to affordable solar energy applications.

[0003] Perovskite solar cells (PVSCs) consist of a transparent conductive electrode, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and electrodes. Nickel oxide (NiO) x NiO, as a commonly used inverse PVSCs hole transport material (HTM), is widely used due to its advantages such as low cost, simple preparation process, and good stability. However, NiO... x As the hole transport layer in inverted perovskite solar cells, the perovskite layer suffers from problems such as energy level mismatch with the perovskite, numerous surface defects, and poor interfacial contact due to lattice mismatch. These issues lead to poor stability of perovskite devices, thus limiting the long-term use of perovskite solar cells. Some methods use SAM (PACz-type) for surface modification, but these SAM layers have poor thermal stability, are prone to thermal degradation at high temperatures, undergo morphological changes leading to performance decline, and experience easy breakage of bonds between anchoring groups and molecules. These issues also pose significant drawbacks to subsequent perovskite process optimization.

[0004] Therefore, how to improve the hole transport layer to enhance the hole transport capability of the device and enable it to have excellent optoelectronic performance and stability is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a composite hole transport layer for solar cells, its preparation method, and its applications. This invention modifies a p-type inorganic or organic semiconductor material layer using a transition metal dichalcogenide as the material for the second hole transport layer. This not only passivates surface defects in the first hole transport layer, improving its hole transport capability and stability, but also improves the energy level mismatch between the hole transport layer and the perovskite light-absorbing layer, optimizing the interface contact. Therefore, this composite hole transport layer can maximize the hole transport capability of the device, resulting in excellent photoelectric performance and stability, which is of great significance for advancing the practical application of perovskite solar cells.

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

[0007] In a first aspect, the present invention provides a composite hole transport layer for a solar cell, the composite hole transport layer comprising a first hole transport layer and a second hole transport layer stacked sequentially.

[0008] The first hole transport layer includes a p-type inorganic semiconductor material layer or a p-type organic semiconductor material layer, and the second hole transport layer includes a transition metal dichalcogenide layer.

[0009] This invention modifies a p-type inorganic or organic semiconductor layer using a transition metal dichalcogenide as the material for the second hole transport layer. This not only passivates surface defects in the first hole transport layer, improving its hole transport capability and stability, but also mitigates the energy level mismatch between the hole transport layer and the perovskite light-absorbing layer, optimizing the interface contact. Therefore, this composite hole transport layer can maximize the hole transport capability of the device, resulting in excellent photoelectric performance and stability. This is of great significance for advancing the practical application of perovskite solar cells.

[0010] As a preferred technical solution of the present invention, the material of the first hole transport layer includes any one or a combination of at least two of Poly-TPD, NiOx, Sprio-TTB, PEDOT:PSS, PTAA, CuI or CuSCN.

[0011] Preferably, the chemical formula of the transition metal dichalcogenide layer includes MX2, where M includes molybdenum and / or tungsten, and X includes any one or a combination of at least two of selenium, sulfur, or tellurium.

[0012] Preferably, the transition metal dichalcogenide includes WSe2.

[0013] It should be noted that transition metal dichalcogenides, also known as TMDs, are two-dimensional materials with tunable band gaps. As the number of layers increases, the band gap changes from a direct band gap (usually a single layer) to an indirect band gap.

[0014] Preferably, the thickness ratio of the first hole transport layer to the second hole transport layer is (3-20):(2-5), wherein the selection range of the first hole transport layer "3-20" can be, for example, 3, 5, 9, 10, 12, 14, 16, 18 or 20, and the selection range of the second hole transport layer "2-5" can be, for example, 2, 3, 4 or 5.

[0015] In this invention, if the thickness ratio of the first hole transport layer to the second hole transport layer is too small, that is, the thickness of the second hole transport layer is too thick, it will lead to excessively high parasitic absorption of the second hole transport layer, resulting in a decrease in the photoelectric efficiency of the battery device; if the thickness ratio of the first hole transport layer to the second hole transport layer is too large, that is, the thickness of the second hole transport layer is too thin, it will lead to a decrease in its hole transport capability.

[0016] In a second aspect, the present invention provides a method for preparing a composite hole transport layer as described in the first aspect, the method comprising the following steps:

[0017] A first hole transport layer and a second hole transport layer are sequentially prepared on the surface of a substrate.

[0018] As a preferred technical solution of the present invention, the preparation method of the first hole transport layer includes any one or a combination of at least two of spin coating, thermal evaporation, magnetron sputtering, atomic deposition or chemical vapor deposition.

[0019] Preferably, the method for preparing the second hole transport layer includes any one or a combination of at least two of the following: spin coating, thermal evaporation, magnetron sputtering, or atomic deposition.

[0020] Preferably, the second hole transport layer is prepared by spin coating, and the specific steps of spin coating include:

[0021] The precursor solution of the second hole transport layer is spin-coated onto the surface of the first hole transport layer, and then annealed to form the second hole transport layer.

[0022] Preferably, the concentration of the precursor solution is 0.5-2 mg / mL, for example, it can be 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL or 2 mg / mL, etc.

[0023] Preferably, the spin coating rate is 2000-5000 rpm, for example, 2000 rpm, 3000 rpm, 3000 rpm or 5000 rpm, and the spin coating time is 25-35 s, for example, 25 s, 30 s or 35 s.

[0024] In this invention, if the spin coating rate is too low, the film thickness will be too thick, which will increase the parasitic absorption of the second hole transport layer and cause the device's photoelectric performance to decline; if the spin coating rate is too high, the film will be too thin, the charge transport capability will decrease, and the device performance will decline.

[0025] Preferably, the annealing temperature is 75-100℃, for example, 75℃, 80℃, 85℃, 90℃, 95℃ or 100℃, and the annealing time is 5-10min, for example, 5min, 6min, 7min, 8min, 9min or 10min.

[0026] In this invention, if the annealing temperature is too low, it will result in poor crystallinity, low film quality, and decreased device performance; if the annealing temperature is too high, it will result in uneven internal structure of the film, leading to film instability and decreased device performance.

[0027] Thirdly, the present invention provides an application of the composite hole transport layer as described in the first aspect in a solar cell.

[0028] As a preferred technical solution of the present invention, the solar cell is a perovskite solar cell, which includes, from bottom to top, a conductive substrate, a composite hole transport layer, a perovskite light-absorbing layer, an electron transport layer and an electrode. The side of the composite hole transport layer closest to the conductive substrate is the first hole transport layer, and the side closest to the perovskite light-absorbing layer is the second hole transport layer.

[0029] As a preferred embodiment of the present invention, the surface of the second hole transport layer near the perovskite light-absorbing layer contains halide ions.

[0030] Preferably, the halide ion includes any one or a combination of at least two of fluoride ions, chloride ions, bromide ions, or iodide ions.

[0031] In this invention, since excess or unreacted B-site cations (e.g., Pb) are commonly used in perovskite light-absorbing layers... 2+After prolonged exposure to light, B-site cations may transform into zero-valent cations, leading to poor stability of the perovskite light-absorbing layer. Therefore, by having halide ions on the surface of the second hole transport layer near the perovskite light-absorbing layer contact the lower surface of the perovskite, they can effectively coordinate with the B-site-rich cations in the perovskite. This effectively suppresses internal defects in the perovskite, reduces the impact of excessive B-site cation content, improves stability, reduces defects between interfaces, improves interfacial contact, solves the non-radiative interface recombination problem, and improves the photoelectric performance and stability of the battery.

[0032] Preferably, a two-dimensional passivation layer is disposed between the perovskite light-absorbing layer and the electron transport layer.

[0033] The purpose of setting a two-dimensional passivation layer between the perovskite light-absorbing layer and the electron transport layer in this invention is to passivate perovskite surface defects and improve the open-circuit voltage of the battery.

[0034] Preferably, the material of the two-dimensional passivation layer includes PEAX, wherein X is any one or a combination of at least two of Cl-, Br-, or I-.

[0035] Preferably, the thickness of the two-dimensional passivation layer is 1-3 nm, for example, it can be 1 nm, 2 nm or 3 nm.

[0036] Preferably, a hole blocking layer is provided between the electron transport layer and the electrode.

[0037] Preferably, the hole blocking layer is made of an n-type semiconductor.

[0038] Preferably, the thickness of the hole blocking layer is 5-10 nm, for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm.

[0039] Preferably, the material of the hole blocking layer includes any one or a combination of at least two of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), SnO2, or PEIE (ethoxylated polyethyleneimine).

[0040] Preferably, the conductive substrate is a transparent glass conductive layer.

[0041] It should be noted that the present invention does not specifically limit the transparent glass conductive layer. For example, it can be FTO (indium fluorine oxide) conductive glass or ITO (indium tin oxide) conductive glass.

[0042] Preferably, the chemical formula of the perovskite light-absorbing layer is ABX3, where A is CH3NH3. + CH(NH2)2 + 、Cs + or Rb+ B is any combination of one or at least two of the following, where B is Pb. 2+ Sn 2+ Or Ge 2+ X is any one or at least two of Cl-, Br-, or I-, where X is any one or at least two of Cl-, Br-, or I-.

[0043] Preferably, the thickness of the perovskite light-absorbing layer is 400-500 nm, for example, it can be 400 nm, 420 nm, 440 nm, 460 nm, 480 nm or 500 nm.

[0044] Preferably, the electron transport layer is made of an n-type semiconductor.

[0045] Preferably, the material of the electron transport layer includes C. 60 Any one or at least two of the following: PCBM, TiO2, SnO2, ZnO, or ZnO-ZnS.

[0046] Preferably, the thickness of the electron transport layer is 10-30 nm, for example, it can be 10 nm, 20 nm or 30 nm.

[0047] Preferably, the electrode is a metal electrode layer.

[0048] Preferably, the thickness of the metal electrode layer is 80-150 nm, for example, it can be 80 nm, 100 nm, 120 nm or 150 nm.

[0049] It should be noted that the present invention does not specifically limit the material of the metal electrode layer. For example, it can be Au, Ag or Cu.

[0050] As a preferred embodiment of the present invention, the method for preparing the perovskite solar cell includes the following steps:

[0051] A first hole transport layer, a second hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode are sequentially fabricated on the surface of a conductive substrate to obtain the perovskite solar cell.

[0052] As a preferred embodiment of the present invention, before preparing the perovskite light-absorbing layer, the second hole transport layer is first surface-modified. The specific steps of the surface modification include:

[0053] A halogen solution is coated onto the surface of the second hole transport layer for surface modification.

[0054] Preferably, the halogen solution includes any one or a combination of at least two of the following: F2 solution, Cl2 solution, Br2 solution, or I2 solution.

[0055] Preferably, the concentration of the halogen solution is 0.1-1 mol / L, for example, it can be 0.1 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L or 0.9 mol / L, etc.

[0056] Preferably, the coating method includes spin coating, wherein the spin coating speed is 1000-5000 rpm, for example, 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm or 5000 rpm, and the time is 20-40 s, for example, 20 s, 30 s or 40 s.

[0057] In this invention, if the spin coating rate is too low, the halide ion content will be too high, resulting in surface charge accumulation and a decrease in device performance; if the spin coating rate is too high, the halide ion content will be too low, resulting in a small modification effect and a decrease in device performance.

[0058] As a preferred embodiment of the present invention, a two-dimensional passivation layer is disposed between the perovskite light-absorbing layer and the electron transport layer. The preparation method of the two-dimensional passivation layer includes spin coating, and the specific steps include:

[0059] The precursor solution of the two-dimensional passivation layer is spin-coated onto the surface of the perovskite light-absorbing layer, followed by a second annealing to form the two-dimensional passivation layer.

[0060] Preferably, the concentration of the precursor solution for the two-dimensional passivation layer is 0.2-1 mg / mL, for example, it can be 0.2 mg / mL, 0.4 mg / mL, 0.6 mg / mL, 0.8 mg / mL or 1 mg / mL, etc.

[0061] Preferably, the spin coating rate of the precursor solution of the two-dimensional passivation layer is 4000-6000 rpm, for example, 4000 rpm, 4500 rpm, 5000 rpm, 5500 rpm or 6000 rpm, and the time is 25-35 s, for example, 25 s, 30 s or 35 s.

[0062] Preferably, the annealing temperature of the precursor solution of the two-dimensional passivation layer is 80-90℃, for example, 80℃, 85℃ or 90℃, and the annealing time is 3-8min, for example, 3min, 4min, 5min, 6min, 7min or 8min.

[0063] Preferably, a hole blocking layer is disposed between the electron transport layer and the electrode, and the hole blocking layer is prepared by any one or a combination of at least two of the following methods: spin coating, thermal evaporation, magnetron sputtering, atomic deposition, or chemical vapor deposition.

[0064] Preferably, the method for preparing the perovskite light-absorbing layer includes any one or a combination of at least two of the following: one-step solution method, wet-dry mixing method, or all-dry vapor deposition.

[0065] It should be noted that the wet-dry mixing method refers to the combination of thermal evaporation and solution methods.

[0066] For example, the perovskite light-absorbing layer is prepared by a dry-wet mixing method, and the specific steps include:

[0067] (a) PbI and CsBr were deposited sequentially using a thermal evaporation method, where the deposition rate of PbI was [missing information]. (for example, it could be) or (etc.), the deposition rate of CsBr is (for example, it could be) or wait);

[0068] (b) A precursor solution containing FAI, FABr, and MACl at a concentration of 0.8-1.5 mol / mL (e.g., 0.8 mol / mL, 1 mol / mL, 1.2 mol / mL, or 1.5 mol / mL, etc.) is spin-coated onto CsBr, wherein the molar ratio of FAI, FABr, and MACl is 10:5:2, the spin speed is 2000-5000 rpm (e.g., 2000 rpm, 3000 rpm, 4000 rpm, or 5000 rpm, etc.), the spin time is 20-40 s (e.g., 20 s, 30 s, or 40 s, etc.), and then annealed at 75-150℃ (e.g., 75℃, 100℃, 125℃, or 150℃, etc.) for 5-15 min (e.g., 5 min, 10 min, or 15 min, etc.) to form a perovskite light-absorbing layer.

[0069] Preferably, the method for preparing the electron transport layer includes any one or a combination of at least two of spin coating, thermal evaporation, or magnetron sputtering.

[0070] Preferably, the electrode is prepared by a thermal evaporation method.

[0071] As a preferred embodiment of the present invention, the method for preparing the perovskite solar cell includes the following steps:

[0072] (1) A nickel oxide layer with a thickness of 3-20 nm was deposited on a conductive substrate by magnetron sputtering.

[0073] (2) Spin-coat the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then perform a first annealing at 75-100℃ for 5-10 min to form a WSe2 layer with a thickness of 2-5 nm.

[0074] (3) A halogen solution with a concentration of 0.1-1 mol / L is spin-coated onto the surface of the WSe2 layer for surface modification;

[0075] (4) Using a dry-wet mixing method, a perovskite light-absorbing layer with a thickness of 400-500 nm is prepared on the surface of the WSe2 layer modified in step (3);

[0076] (5) Spin-coat the surface of the perovskite light-absorbing layer with a precursor solution of 0.2-1 mg / mL, and then perform a second annealing at 80-90℃ for 3-8 min to form a two-dimensional passivation layer with a thickness of 1-3 nm.

[0077] (6) An electron transport layer with a thickness of 10-30 nm is deposited on the surface of the two-dimensional passivation layer using a thermal evaporation method, wherein the deposition rate is...

[0078] (7) A hole blocking layer with a thickness of 5-10 nm is deposited on the surface of the electron transport layer by thermal evaporation.

[0079] (8) A metal electrode with a thickness of 80-150 nm is thermally evaporated and deposited on the surface of the hole blocking layer.

[0080] Specifically, the fabrication method of the perovskite solar cell includes the following steps:

[0081] (1) A nickel oxide layer with a thickness of 3-20 nm is deposited on a transparent glass conductive layer using magnetron sputtering. The process conditions for the magnetron sputtering method include:

[0082] Vacuum degree ≤5×10 -3 Pa, the protective atmosphere has an oxygen volume fraction of 1-5% and a power density of 0.5-5 W / cm³. 2 The pressure is 0.3-1.5 Pa;

[0083] The protective atmosphere further includes an inert gas, which includes argon.

[0084] (2) Spin-coat the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then perform a first annealing at 75-100℃ for 5-10 min to form a WSe2 layer with a thickness of 2-5 nm.

[0085] The concentration of the precursor solution was 0.5-2 mg / ml, the spin coating rate was 2000-5000 rpm, and the spin coating time was 25-35 s.

[0086] (3) A halogen solution with a concentration of 0.1-1 mol / L is spin-coated onto the surface of the WSe2 layer for surface modification;

[0087] The spin coating rate is 1000-5000 rpm, and the spin coating time is 20-40 s.

[0088] (4) Using a dry-wet mixing method, a perovskite light-absorbing layer with a thickness of 400-500 nm is prepared on the surface of the WSe2 layer modified in step (3);

[0089] (5) Spin-coat the surface of the perovskite light-absorbing layer with a precursor solution of 0.2-1 mg / mL, and then perform a second annealing at 80-90℃ for 3-8 min to form a two-dimensional passivation layer with a thickness of 1-3 nm.

[0090] The spin coating rate is 4000-6000 rpm, and the time is 25-35 s;

[0091] (6) An electron transport layer with a thickness of 10-30 nm is deposited on the surface of the two-dimensional passivation layer using a thermal evaporation method, wherein the deposition rate is...

[0092] (7) A hole-blocking layer with a thickness of 5-10 nm is deposited on the surface of the electron transport layer using a thermal evaporation method, wherein the deposition rate is...

[0093] (8) A metal electrode with a thickness of 80-150 nm is thermally evaporated and deposited on the surface of the hole blocking layer, wherein the thermal evaporation deposition rate is...

[0094] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0095] Compared with the prior art, the present invention has the following beneficial effects:

[0096] This invention modifies a p-type inorganic or organic semiconductor layer using a transition metal dichalcogenide as the second hole transport layer. This not only passivates surface defects in the first hole transport layer, improving its hole transport capability and stability, but also, as a direct bandgap semiconductor material, passivates the lower surface of the perovskite absorber layer, improving the energy level mismatch between the nickel oxide layer and the perovskite absorber layer and optimizing the interface contact. Furthermore, it can also function as a hole transport layer for hole transport. Therefore, this composite hole transport layer can maximize the hole transport capability of the device, resulting in excellent photoelectric performance and stability. This is of great significance for advancing the practical application of perovskite solar cells. Attached Figure Description

[0097] Figure 1 This is a schematic diagram of the structure of the perovskite solar cell prepared in Example 1 of the present invention.

[0098] Figure 2 This is a comparison chart showing the stability of perovskite solar cells prepared in Examples 1, 4, and Comparative Examples 1-2 of this invention.

[0099] Among them, 1-ITO conductive glass; 2-first hole transport layer; 3-second hole transport layer; 4-perovskite light-absorbing layer; 5-two-dimensional passivation layer; 6-electron transport layer; 7-hole blocking layer; 8-metal electrode layer. Detailed Implementation

[0100] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0101] Example 1

[0102] This embodiment provides a composite hole transport layer for solar cells, the composite hole transport layer comprising a first hole transport layer and a second hole transport layer stacked sequentially.

[0103] The first hole transport layer is a nickel oxide layer, and the second hole transport layer is a WSe2 layer;

[0104] The thickness ratio of the first hole transport layer to the second hole transport layer is 10:4.

[0105] This embodiment also provides a method for preparing the above-mentioned composite hole transport layer, the method comprising the following steps:

[0106] (a) A nickel oxide layer with a thickness of 10 nm is deposited on a substrate using magnetron sputtering, wherein the process conditions for the magnetron sputtering method include:

[0107] Vacuum degree is 1×10 -3 Pa, with a protective atmosphere where the volume ratio of oxygen to argon is 3:97 and the power density is 3 W / cm³. 2 The pressure is 1 Pa;

[0108] (b) Spin-coating the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then annealing it at 100°C for 10 min to form a WSe2 layer with a thickness of 4 nm.

[0109] The concentration of the precursor solution was 1 mg / mL, the spin coating rate was 3000 rpm, and the spin coating time was 30 s.

[0110] This embodiment also provides a perovskite solar cell, the structural schematic of which is shown below. Figure 1 As shown, the perovskite solar cell comprises, from bottom to top, ITO conductive glass 1, a composite hole transport layer as described above, a perovskite light-absorbing layer 4, a two-dimensional passivation layer 5, an electron transport layer 6, a hole blocking layer 7, and a metal electrode layer 8.

[0111] The side of the composite hole transport layer closest to the ITO conductive glass 1 is the first hole transport layer 2, and the side closest to the perovskite light-absorbing layer 4 is the second hole transport layer 3.

[0112] The surface of the second hole transport layer 3 near the perovskite light-absorbing layer 4 contains halide ions, which are bromine atoms.

[0113] The two-dimensional passivation layer 5 is a PEAI layer with a thickness of 2nm; the hole blocking layer 7 is a BCP layer with a thickness of 8nm.

[0114] The thickness of the perovskite light-absorbing layer 5 is 450 nm;

[0115] The electron transport layer 6 is C. 60 The layer is 20nm thick;

[0116] The metal electrode layer 8 is an Ag layer with a thickness of 100 nm.

[0117] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, the method comprising the following steps:

[0118] (1) Clean the ITO conductive glass 1, specifically by ultrasonic cleaning with detergent, deionized water, acetone and anhydrous ethanol respectively, and then drying it with a nitrogen gun.

[0119] The ultrasonic cleaning power is 100Hz and the ultrasonic cleaning time is 15min.

[0120] (2) A nickel oxide layer with a thickness of 10 nm is deposited on ITO conductive glass 1 using magnetron sputtering. The process conditions for the magnetron sputtering method include:

[0121] Vacuum degree is 1×10 -3 Pa, with a protective atmosphere where the volume ratio of oxygen to argon is 3:97 and the power density is 3 W / cm³. 2 The pressure is 1 Pa;

[0122] (3) Spin-coat the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then anneal it at 100°C for 10 min to form a WSe2 layer with a thickness of 4 nm.

[0123] The concentration of the precursor solution was 1 mg / ml, the spin coating rate was 3000 rpm, and the spin coating time was 30 s.

[0124] (4) Spin-coating a Br2 solution with a concentration of 0.5 mol / L onto the surface of the WSe2 layer to perform surface modification;

[0125] The spin coating rate was 3000 rpm and the spin coating time was 30 s.

[0126] (5) Using a dry-wet mixing method, a perovskite light-absorbing layer 4 with a thickness of 450 nm is prepared on the surface of the WSe2 layer modified in step (3). The specific steps include:

[0127] a. PbI and CsBr are deposited sequentially using a thermal evaporation method, wherein the deposition rate of PbI is: The deposition rate of CsBr is

[0128] b. Spin-coat a precursor solution containing FAI, FABr and MACl at a concentration of 1.2 mol / mL onto CsBr, wherein the molar ratio of FAI, FABr and MACl is 10:5:2, at a rotation speed of 3500 rpm for 30 s, and then anneal at 120 °C for 10 min to form a perovskite light-absorbing layer 4.

[0129] (6) Spin-coat the surface of the perovskite light-absorbing layer 4 with a PEAI solution of 0.6 mg / mL, and then anneal at 85°C for 5 min to form a PEAI layer with a thickness of 2 nm.

[0130] The spin coating rate was 5000 rpm and the time was 30 s.

[0131] (7) Using a thermal evaporation method, a C layer with a thickness of 20 nm is deposited on the surface of the PEAI layer. 60 The layer, the deposition rate is

[0132] (8) Using the thermal evaporation method, in the C 60 A BCP layer with a thickness of 8 nm is deposited on the surface of the layer, and the deposition rate is...

[0133] (9) An Ag electrode with a thickness of 120 nm is thermally evaporated and deposited on the surface of the BCP layer, wherein the thermal evaporation deposition rate is...

[0134] Example 2

[0135] This embodiment provides a composite hole transport layer for solar cells, the composite hole transport layer comprising a first hole transport layer and a second hole transport layer stacked sequentially.

[0136] The first hole transport layer is a nickel oxide layer, and the second hole transport layer is a WSe2 layer;

[0137] The thickness ratio of the first hole transport layer to the second hole transport layer is 15:5.

[0138] This embodiment also provides a method for preparing the above-mentioned composite hole transport layer, the method comprising the following steps:

[0139] (a) A nickel oxide layer with a thickness of 15 nm is deposited on a substrate using magnetron sputtering, wherein the process conditions for the magnetron sputtering method include:

[0140] Vacuum degree is 1×10 -3 Pa, with a protective atmosphere where the volume ratio of oxygen to argon is 3:97 and the power density is 3 W / cm³. 2 The pressure is 1 Pa;

[0141] (b) Spin-coating the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then annealing it at 75°C for 10 min to form a WSe2 layer with a thickness of 5 nm.

[0142] The precursor solution concentration was 1.5 mg / mL, the spin coating rate was 2000 rpm, and the spin coating time was 25 s.

[0143] This embodiment also provides a perovskite solar cell, which, from bottom to top, includes ITO conductive glass, a composite hole transport layer as described above, a perovskite light-absorbing layer, a two-dimensional passivation layer, an electron transport layer, a hole blocking layer, and a metal electrode layer.

[0144] The side of the composite hole transport layer closest to the ITO conductive glass is the first hole transport layer, and the side closest to the perovskite light-absorbing layer is the second hole transport layer.

[0145] The second hole transport layer contains halide ions on the surface near the perovskite light-absorbing layer, and the halide ions are iodine atoms.

[0146] The two-dimensional passivation layer is a PEAI layer with a thickness of 1 nm; the hole blocking layer is a BCP layer with a thickness of 5 nm.

[0147] The thickness of the perovskite light-absorbing layer is 400 nm;

[0148] The electron transport layer is C. 60 The layer is 10 nm thick.

[0149] The metal electrode layer is an Au layer with a thickness of 80 nm.

[0150] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, the method comprising the following steps:

[0151] (1) Clean the ITO conductive glass, specifically by ultrasonic cleaning with detergent, deionized water, acetone and anhydrous ethanol respectively, and then drying it with a nitrogen gun.

[0152] The ultrasonic cleaning power is 100Hz and the ultrasonic cleaning time is 15min.

[0153] (2) A nickel oxide layer with a thickness of 15 nm is deposited on ITO conductive glass using magnetron sputtering. The process conditions for the magnetron sputtering method include:

[0154] Vacuum degree is 1×10 -3 Pa, with a protective atmosphere where the volume ratio of oxygen to argon is 1:99 and the power density is 1 W / cm³. 2 The pressure is 0.5 Pa;

[0155] (3) Spin-coat the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then anneal it at 75°C for 10 min to form a WSe2 layer with a thickness of 5 nm.

[0156] The concentration of the precursor solution was 1.5 mg / mL, the spin coating rate was 2000 rpm, and the spin coating time was 25 s.

[0157] (4) Spin-coating a 0.1 mol / L I2 solution onto the surface of the WSe2 layer to perform surface modification;

[0158] The spin coating rate was 1000 rpm and the spin coating time was 20 s.

[0159] (5) Using a dry-wet mixing method, a perovskite light-absorbing layer with a thickness of 400 nm is prepared on the surface of the WSe2 layer modified in step (3). The specific steps include:

[0160] a. PbI and CsBr are deposited sequentially using a thermal evaporation method, wherein the deposition rate of PbI is: The deposition rate of CsBr is

[0161] b. Spin-coat a precursor solution containing FAI, FABr and MACl at a concentration of 0.8 mol / mL onto CsBr, wherein the molar ratio of FAI, FABr and MACl is 10:5:2, at a rotation speed of 2000 rpm for 20 s, and then anneal at 75 °C for 15 min to form a perovskite light-absorbing layer.

[0162] (6) Spin-coat the surface of the perovskite light-absorbing layer with a PEAI solution of 0.2 mg / mL, and then anneal at 80°C for 8 min to form a PEAI layer with a thickness of 1 nm.

[0163] The spin coating rate was 4000 rpm and the time was 25 s.

[0164] (7) Using a thermal evaporation method, a C layer with a thickness of 10 nm is deposited on the surface of the PEAI layer. 60 The layer, the deposition rate is

[0165] (8) Using the thermal evaporation method, in the C 60 A 5 nm thick BCP layer is deposited on the surface of the layer, and the deposition rate is...

[0166] (9) An Ag electrode with a thickness of 80 nm is thermally evaporated and deposited on the surface of the BCP layer, wherein the thermal evaporation deposition rate is...

[0167] Example 3

[0168] This embodiment provides a composite hole transport layer for solar cells, the composite hole transport layer comprising a first hole transport layer and a second hole transport layer stacked sequentially.

[0169] The first hole transport layer is a nickel oxide layer, and the second hole transport layer is a WSe2 layer;

[0170] The thickness ratio of the first hole transport layer to the second hole transport layer is 5:2.

[0171] This embodiment also provides a method for preparing the above-mentioned composite hole transport layer, the method comprising the following steps:

[0172] (a) A nickel oxide layer with a thickness of 20 nm is deposited on a substrate using magnetron sputtering, wherein the process conditions for the magnetron sputtering method include:

[0173] Vacuum degree is 1×10 -3 Pa, with a protective atmosphere where the volume ratio of oxygen to argon is 3:97 and the power density is 3 W / cm³. 2 The pressure is 1 Pa;

[0174] (b) Spin-coating the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then annealing it at 85°C for 8 min to form a WSe2 layer with a thickness of 8 nm.

[0175] The concentration of the precursor solution was 2 mg / mL, the spin coating rate was 5000 rpm, and the spin coating time was 35 s.

[0176] This embodiment also provides a perovskite solar cell, which, from bottom to top, includes ITO conductive glass, a composite hole transport layer as described above, a perovskite light-absorbing layer, a two-dimensional passivation layer, an electron transport layer, a hole blocking layer, and a metal electrode layer.

[0177] The side of the composite hole transport layer closest to the ITO conductive glass is the first hole transport layer, and the side closest to the perovskite light-absorbing layer is the second hole transport layer.

[0178] The surface of the second hole transport layer near the perovskite light-absorbing layer contains halide ions, which are chlorine atoms;

[0179] The two-dimensional passivation layer is a PEAI layer with a thickness of 3nm; the hole blocking layer is a BCP layer with a thickness of 10nm.

[0180] The thickness of the perovskite light-absorbing layer is 500 nm;

[0181] The electron transport layer is C. 60 The layer is 30nm thick;

[0182] The metal electrode layer is an Au layer with a thickness of 150 nm.

[0183] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, the method comprising the following steps:

[0184] (1) Clean the ITO conductive glass, specifically by ultrasonic cleaning with detergent, deionized water, acetone and anhydrous ethanol respectively, and then drying it with a nitrogen gun.

[0185] The ultrasonic cleaning power is 100Hz and the ultrasonic cleaning time is 15min.

[0186] (2) A nickel oxide layer with a thickness of 20 nm is deposited on ITO conductive glass using magnetron sputtering. The process conditions for the magnetron sputtering method include:

[0187] Vacuum degree is 1×10 -3 Pa, with a protective atmosphere containing oxygen and argon in a volume ratio of 5:95 and a power density of 5 W / cm³. 2 The pressure is 1.5 Pa.

[0188] (3) Spin-coat the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then anneal it at 85°C for 8 min to form a WSe2 layer with a thickness of 8 nm.

[0189] The concentration of the precursor solution was 2 mg / ml, the spin coating rate was 5000 rpm, and the spin coating time was 35 s.

[0190] (4) A 1 mol / L Cl2 solution was spin-coated onto the surface of the WSe2 layer for surface modification;

[0191] The spin coating rate was 5000 rpm and the spin coating time was 40 s.

[0192] (5) Using a dry-wet mixing method, a perovskite light-absorbing layer with a thickness of 500 nm is prepared on the surface of the WSe2 layer modified in step (3). The specific steps include:

[0193] a. PbI and CsBr are deposited sequentially using a thermal evaporation method, wherein the deposition rate of PbI is: The deposition rate of CsBr is

[0194] b. Spin-coat a precursor solution containing FAI, FABr and MACl at a concentration of 1.5 mol / mL onto CsBr, wherein the molar ratio of FAI, FABr and MACl is 10:5:2, at a rotation speed of 5000 rpm for 40 s, and then anneal at 150 °C for 5 min to form a perovskite light-absorbing layer.

[0195] (6) Spin-coat the surface of the perovskite light-absorbing layer with a PEAI solution of 1 mg / mL, and then anneal at 90°C for 3 min to form a PEAI layer with a thickness of 3 nm.

[0196] The spin coating rate was 4000 rpm and the time was 30 s.

[0197] (7) Using a thermal evaporation method, a C layer with a thickness of 30 nm is deposited on the surface of the PEAI layer. 60 The layer, the deposition rate is

[0198] (8) Using the thermal evaporation method, in the C 60 A 10 nm thick BCP layer is deposited on the surface of the layer, and the deposition rate is...

[0199] (9) An Ag electrode with a thickness of 150 nm is thermally evaporated and deposited on the surface of the BCP layer, wherein the thermal evaporation deposition rate is...

[0200] Example 4

[0201] The difference between this embodiment and embodiment 1 is that the Br2 solution in step (4) is replaced with the Cl2 solution.

[0202] The remaining preparation methods and parameters are consistent with those in Example 1.

[0203] Example 5

[0204] The difference between this embodiment and Embodiment 1 is that the thickness ratio of the first hole transport layer and the second hole transport layer is 3:10.

[0205] The remaining preparation methods and parameters are consistent with those in Example 1.

[0206] Example 6

[0207] The difference between this embodiment and embodiment 1 is that the spin coating rate in step (3) is adjusted so that the thickness ratio of the first hole transport layer and the second hole transport layer is 20:1.

[0208] The remaining preparation methods and parameters are consistent with those in Example 1.

[0209] Example 7

[0210] The difference between this embodiment and Embodiment 1 is that the annealing temperature of the precursor solution for the WSe2 layer is 70°C.

[0211] The remaining preparation methods and parameters are consistent with those in Example 1.

[0212] Example 8

[0213] The difference between this embodiment and Embodiment 1 is that the annealing temperature of the precursor solution for the WSe2 layer is 110°C.

[0214] The remaining preparation methods and parameters are consistent with those in Example 1.

[0215] Example 9

[0216] The difference between this embodiment and embodiment 1 is that step (4) is not performed, that is, the surface of the second hole transport layer near the perovskite light-absorbing layer does not contain halogen ions.

[0217] The remaining preparation methods and parameters are consistent with those in Example 1.

[0218] Example 10

[0219] The difference between this embodiment and embodiment 1 is that the spin coating rate in step (4) is 500 rpm.

[0220] The remaining preparation methods and parameters are consistent with those in Example 1.

[0221] Example 11

[0222] The difference between this embodiment and embodiment 1 is that the spin coating rate in step (4) is 6000 rpm.

[0223] The remaining preparation methods and parameters are consistent with those in Example 1.

[0224] Example 12

[0225] The difference between this embodiment and embodiment 1 is that step (6) is omitted.

[0226] The remaining preparation methods and parameters are consistent with those in Example 1.

[0227] Comparative Example 1

[0228] The difference between this comparative example and Example 4 is that the precursor solution of the WSe2 layer is replaced with MeO-2PACz ([2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid) to form the MeO-2PACz layer.

[0229] The remaining preparation methods and parameters are consistent with those in Example 4.

[0230] Comparative Example 2

[0231] The difference between this comparative example and Example 1 is that the WSe2 layer is not provided.

[0232] The remaining preparation methods and parameters are consistent with those in Example 1.

[0233] Performance testing

[0234] The perovskite solar cells prepared in the above embodiments and comparative examples were subjected to photoelectric performance testing and stability testing.

[0235] The conditions for photoelectric performance testing were: the effective area of ​​each battery was 1 cm². 2 AM1.5, 1000W / m2 , 25±2℃.

[0236] The stability test conditions were: 85℃, relative humidity 85%, and the battery efficiency was tested after 1000 hours, and the efficiency retention rate was recorded.

[0237] The above test results are as follows Figure 2 As shown in Table 1.

[0238] Figure 2 The stability comparison diagrams of the perovskite solar cells prepared in Examples 1, 4, and Comparative Examples 1-2 are shown. As can be seen from the diagrams, the perovskite solar cell constructed by the synergistic effect of the WSe2 layer treated with halogen solution and nickel oxide retains more than 96% of its initial stability after 1000 hours. In contrast, the perovskite solar cell prepared based on a single layer of nickel oxide and a nickel oxide layer modified with MeO-2PACz exhibits a faster degradation rate. This is mainly because WSe2, being a two-dimensional material, improves the interfacial contact between the hole transport layer and the perovskite light-absorbing layer compared to traditional nickel oxide, reducing interfacial defects and solving the non-radiative interfacial recombination problem. The halogen ions suspended on the surface of the WSe2 film after halogen ion treatment react with the Pb on the lower surface of the perovskite light-absorbing layer. 2+ The improved isotropic coordination capability enhances the photoelectric performance and stability of the battery.

[0239] Table 1

[0240]

[0241] analyze:

[0242] As shown in the table above, this invention modifies the nickel oxide layer by introducing a transition metal dichalcogenide. This serves several purposes: firstly, it passivates surface defects in the nickel oxide layer, improving its hole transport capability and stability; secondly, it acts as a two-dimensional material to passivate the lower surface of the perovskite light-absorbing layer, resulting in better interfacial contact; and thirdly, it serves as a direct bandgap semiconductor material, improving the energy level mismatch between the nickel oxide layer and the perovskite light-absorbing layer and optimizing the interfacial contact. Furthermore, as a p-type semiconductor, it can also act as a hole transport layer for hole transport. Therefore, this dual hole transport layer can maximize the hole transport capability of the device, resulting in excellent optoelectronic performance and stability.

[0243] As can be seen from Examples 1 and 4, the device with WSe2 layer treated with Br2 solution exhibits superior performance. This is because treating the WSe2 layer with Br reduces the contact resistance. Due to the reduced channel resistance at the interface, charge transport in the channel is improved, and hole transport capability is significantly enhanced. Furthermore, the Pb-Br bond is stronger than the Pb-I bond, resulting in a more stable interface structure.

[0244] As can be seen from Examples 1 and 5-6, if the thickness ratio of the first hole transport layer to the second hole transport layer is too small, that is, the thickness of the second hole transport layer is too thick, it will lead to excessively high parasitic absorption of the second hole transport layer, resulting in a decrease in the photoelectric efficiency of the battery device; if the thickness ratio of the first hole transport layer to the second hole transport layer is too large, that is, the thickness of the second hole transport layer is too thin, it will lead to a decrease in its hole transport capability.

[0245] As can be seen from Examples 1 and 7-8, if the temperature of the first annealing is too low, it will result in poor crystallinity, low film quality, and decreased device performance; if the temperature of the first annealing is too high, it will result in uneven internal structure of the film, leading to film instability and decreased device performance.

[0246] As can be seen from Examples 1 and 9, if the surface of the second hole transport layer near the perovskite light-absorbing layer does not contain halide ions, then the perovskite is rich in Pb. 2+ Ions may be converted into Pb after prolonged exposure to light. 0 The presence of perovskite on the surface leads to decreased stability and reduced photoelectric performance of the battery.

[0247] As can be seen from Examples 1 and 10-11, if the spin coating rate of the halogen solution is too low, the halogen ion content will be too high, resulting in surface charge accumulation and a decrease in device performance; if the spin coating rate of the halogen solution is too high, the halogen ion content will be too low, the modification effect will be small, and the device performance will decrease.

[0248] As can be seen from Examples 1 and 12, if a two-dimensional passivation layer is not provided, the surface defects of the perovskite cannot be modified, resulting in an excessively low open-circuit voltage.

[0249] As shown in Example 1 and Comparative Example 1, using MeO-2PACz to modify the nickel oxide layer results in materials with poor thermal stability, prone to thermal degradation and morphological changes at high temperatures. This leads to performance degradation and easy breakage of bonds between anchoring groups and molecules, which significantly hinders subsequent perovskite process optimization. However, the WSe2 layer provided in Example 1 effectively passivates surface defects in the nickel oxide layer, improves its hole transport capability and stability, and serves as a two-dimensional material to passivate the lower surface of the perovskite light-absorbing layer. This improves the energy level mismatch between the nickel oxide layer and the perovskite light-absorbing layer, optimizes interface contact, and ultimately enables the device to exhibit excellent photoelectric performance and stability.

[0250] As can be seen from Example 1 and Comparative Example 2, if the WSe2 layer is not provided, the problems caused by the pure nickel oxide layer as a hole transport layer cannot be effectively solved, namely, the mismatch between the energy level and the perovskite, poor interface contact, etc., which limit the requirements for long-term use of perovskite solar cells.

[0251] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A composite hole transport layer for solar cells, characterized in that, The composite hole transport layer includes a first hole transport layer and a second hole transport layer stacked sequentially. The first hole transport layer includes a p-type inorganic semiconductor material layer or a p-type organic semiconductor material layer, and the second hole transport layer includes a transition metal dichalcogenide layer.

2. The composite hole transport layer according to claim 1, characterized in that, The material of the first hole transport layer includes any one or a combination of at least two of Poly-TPD, NiOx, Sprio-TTB, PEDOT:PSS, PTAA, CuI, or CuSCN; Preferably, the chemical formula of the transition metal dichalcogenide layer includes MX2, wherein M includes molybdenum and / or tungsten, and X includes any one or a combination of at least two of selenium, sulfur, or tellurium; Preferably, the thickness ratio of the first hole transport layer to the second hole transport layer is (3-20):(2-5).

3. A method for preparing a composite hole transport layer as described in claim 1 or 2, characterized in that, The preparation method includes the following steps: A first hole transport layer and a second hole transport layer are sequentially prepared on the surface of a substrate.

4. The preparation method according to claim 3, characterized in that, The method for preparing the first hole transport layer includes any one or a combination of at least two of spin coating, thermal evaporation, magnetron sputtering, atomic deposition, or chemical vapor deposition. Preferably, the method for preparing the second hole transport layer includes any one or a combination of at least two of the following: spin coating, thermal evaporation, magnetron sputtering, or atomic deposition. Preferably, the second hole transport layer is prepared by spin coating, and the specific steps of spin coating include: The precursor solution of the second hole transport layer is spin-coated onto the surface of the first hole transport layer, and then annealed to form the second hole transport layer. Preferably, the concentration of the precursor solution is 0.5-2 mg / mL; Preferably, the spin coating rate is 2000-5000 rpm and the spin coating time is 25-35 s; Preferably, the annealing temperature is 75-100℃ and the annealing time is 5-10 minutes.

5. An application of the composite hole transport layer as described in claim 1 or 2 in a solar cell.

6. The application according to claim 5, characterized in that, The solar cell is a perovskite solar cell, which includes, from bottom to top, a conductive substrate, a composite hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode. The side of the composite hole transport layer closest to the conductive substrate is the first hole transport layer, and the side closest to the perovskite light-absorbing layer is the second hole transport layer. Preferably, the surface of the second hole transport layer near the perovskite light-absorbing layer contains halide ions; Preferably, the halide ion includes any one or a combination of at least two of fluoride ions, chloride ions, bromide ions, or iodide ions; Preferably, a two-dimensional passivation layer is disposed between the perovskite light-absorbing layer and the electron transport layer; Preferably, the material of the two-dimensional passivation layer includes PEAX, wherein X is any one or a combination of at least two of Cl-, Br-, or I-; Preferably, the thickness of the two-dimensional passivation layer is 1-3 nm; Preferably, a hole blocking layer is provided between the electron transport layer and the electrode; Preferably, the hole blocking layer is made of an n-type semiconductor.

7. The application according to claim 6, characterized in that, The method for preparing the perovskite solar cell includes the following steps: A first hole transport layer, a second hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode are sequentially fabricated on the surface of a conductive substrate to obtain the perovskite solar cell.

8. The application according to claim 7, characterized in that, Before preparing the perovskite light-absorbing layer, the second hole transport layer is first surface-modified. The specific steps of the surface modification include: A halogen solution is coated onto the surface of the second hole transport layer for surface modification. Preferably, the concentration of the halogen solution is 0.1-1 mol / L; Preferably, the coating method includes spin coating, wherein the spin coating speed is 1000-5000 rpm and the time is 20-40 s.

9. The application according to claim 7 or 8, characterized in that, A two-dimensional passivation layer is disposed between the perovskite light-absorbing layer and the electron transport layer. The preparation method of the two-dimensional passivation layer includes spin coating, and the specific steps include: The precursor solution of the two-dimensional passivation layer is spin-coated onto the surface of the perovskite light-absorbing layer, and then annealed to form the two-dimensional passivation layer. Preferably, the concentration of the precursor solution for the two-dimensional passivation layer is 0.2-1 mg / mL; Preferably, the spin-coating rate of the precursor solution for the two-dimensional passivation layer is 4000-6000 rpm, and the time is 25-35 s; Preferably, the annealing temperature of the precursor solution for the two-dimensional passivation layer is 80-90°C, and the annealing time is 3-8 min. Preferably, a hole blocking layer is disposed between the electron transport layer and the electrode, and the hole blocking layer is prepared by any one or a combination of at least two of the following methods: spin coating, thermal evaporation, magnetron sputtering, atomic deposition, or chemical vapor deposition.

10. The application according to any one of claims 7-9, characterized in that, The method for preparing the perovskite solar cell includes the following steps: (1) A nickel oxide layer with a thickness of 3-20 nm was deposited on a conductive substrate by magnetron sputtering. (2) Spin-coat the precursor solution of the WSe2 layer onto the surface of the nickel oxide layer, and then perform a first annealing at 75-100℃ for 5-10 min to form a WSe2 layer with a thickness of 2-5 nm. (3) A halogen solution with a concentration of 0.1-1 mol / L is spin-coated onto the surface of the WSe2 layer for surface modification; (4) Using a dry-wet mixing method, a perovskite light-absorbing layer with a thickness of 400-500 nm is prepared on the surface of the WSe2 layer modified in step (3); (5) Spin-coat the surface of the perovskite light-absorbing layer with a precursor solution of 0.2-1 mg / mL, and then perform a second annealing at 80-90℃ for 3-8 min to form a two-dimensional passivation layer with a thickness of 1-3 nm. (6) An electron transport layer with a thickness of 10-30 nm is deposited on the surface of the two-dimensional passivation layer using a thermal evaporation method, wherein the deposition rate is... (7) A hole blocking layer with a thickness of 5-10 nm is deposited on the surface of the electron transport layer by thermal evaporation. (8) A metal electrode with a thickness of 80-150 nm is thermally evaporated and deposited on the surface of the hole blocking layer.

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