Perovskite solar cells, their fabrication methods, and electrical devices

Abstract

This application relates to perovskite solar cells, their fabrication methods, and electrical devices. The perovskite solar cell of this application comprises a first hole transport layer, a second hole transport layer, and a perovskite layer stacked together, with the second hole transport layer located between the first hole transport layer and the perovskite layer. The material of the first hole transport layer includes nickel oxide; the raw materials of the second hole transport layer include self-assembled monolayer materials and additives; the additives include ester compounds having phosphate groups and multiple alkenyl groups. The perovskite solar cell of this application can solve the problem of insufficient passivation of nickel oxide surface defects by self-assembled monolayer materials, thereby simultaneously achieving high photoelectric conversion efficiency and device stability.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to perovskite solar cells and their preparation methods and electrical devices. Background Technology

[0002] Perovskite solar cells have attracted widespread attention in the photovoltaic field in recent years due to their high photoelectric conversion efficiency, low cost, and ease of fabrication. Nickel oxide, as a hole transport material, possesses characteristics such as high hole mobility, excellent transport efficiency, and strong stability, and is widely used as the hole transport layer in perovskite solar cells. However, nickel oxide is prone to surface defects, especially oxygen vacancy defects, which lead to the formation of defect recombination centers at the perovskite-nickel oxide interface, affecting device efficiency and stability. Currently, the bilayer hole transport layer scheme of nickel oxide plus a self-assembled monolayer is widely adopted. The introduction of the self-assembled monolayer can optimize the contact interface between the perovskite layer and nickel oxide to some extent. However, the passivation effect of traditional self-assembled monolayers on nickel oxide surface defects is still limited. Summary of the Invention

[0003] Therefore, it is necessary to provide perovskite solar cells, their fabrication methods, and electrical devices. The perovskite solar cell of this application can solve the problem of insufficient passivation of nickel oxide surface defects by self-assembled monolayer materials, thereby simultaneously possessing high photoelectric conversion efficiency and device stability.

[0004] In a first aspect, this application provides a perovskite solar cell, comprising a first hole transport layer, a second hole transport layer, and a perovskite layer stacked together, wherein the second hole transport layer is located between the first hole transport layer and the perovskite layer; the material of the first hole transport layer includes nickel oxide; the raw materials of the second hole transport layer include a self-assembled monolayer material and additives; the additives include ester compounds having phosphate groups and multiple alkenyl groups.

[0005] In some embodiments, the additive includes at least one of triallyl phosphate, diallyl phosphate, diallyl methyl phosphate, and diallyl ethyl phosphate.

[0006] In some embodiments, the mass ratio of the additive to the self-assembled monolayer material in the second hole transport layer is 1:(10~100).

[0007] In some embodiments, the self-assembled monolayer material includes at least one of Ph-4PACz, Me-PhpPACz, 4PABCz, 2PABCz, MeO-Ph-4PACz, Br-Ph-4PACz, F-Ph-4PACz, 2PACz, MeO-2PACz, Cl-2PACz, Br-2PACz, I-2PACz, 4PACz, MeO-4PACz, Me-4PACz, BrMeO-4PACz, BrMeOPh-4PACz, 2PADCB, 4PADCB, MeO-4PADCB, Br-4PADCB, DMACPA, 4PAPTZ, Br-4PAPTZ, 4PAPXZ, Br-4PAPXZ, MPA-CPA, DMICPA, PAInCz, DCZ-4P, D4PA, and MeOF-Ph-4PACz.

[0008] In some embodiments, the thickness of the second hole transport layer is 1 nm to 5 nm.

[0009] In some embodiments, the perovskite solar cell includes a substrate, a transparent conductive layer, a first hole transport layer, a second hole transport layer, a perovskite layer, an electron transport layer, and an electrode, which are stacked sequentially.

[0010] Secondly, this application provides a method for preparing a perovskite solar cell, comprising the following steps:

[0011] A precursor solution is obtained by dissolving a self-assembled monolayer material and an additive in an organic solvent, wherein the additive includes an ester compound having a phosphate group and multiple alkenyl groups.

[0012] The precursor solution is applied to the surface of a first hole transport layer, wherein the material of the first hole transport layer includes nickel oxide, to obtain a first precursor film.

[0013] The first precursor film is annealed to prepare a second hole transport layer on the surface of the first hole transport layer.

[0014] A perovskite layer is prepared on the surface of the second hole transport layer that is opposite to the first hole transport layer.

[0015] In some embodiments, the concentration of the self-assembled monolayer material in the precursor solution is 0.1 mg / mL to 1 mg / mL; and the concentration of the additive is 0.001 mg / mL to 0.1 mg / mL.

[0016] In some embodiments, the annealing temperature is 80°C to 120°C; the annealing time is 5 min to 20 min.

[0017] Thirdly, this application provides an electrical device comprising the perovskite solar cell described in any one of the above descriptions or a perovskite solar cell prepared by the method described in any one of the above descriptions; the perovskite solar cell is used to supply power to the electrical device.

[0018] In the aforementioned perovskite solar cell, the raw materials for the second hole transport layer include a self-assembled monolayer material and additives. The additives include ester compounds containing phosphate groups and multiple alkenyl groups. Introducing ester compounds containing phosphate groups and multiple alkenyl groups as additives into the self-assembled monolayer material allows the additives to anchor to the nickel oxide of the first hole transport layer via the phosphate groups during film formation. The additives and the self-assembled monolayer material form a competitive coordination anchoring mechanism. The addition of additives, without affecting the film formation of the self-assembled monolayer material, enables more complete coordination passivation of defects on the nickel oxide surface, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0019] Furthermore, the multiple alkenyl groups in the additive molecules can also cross-link during film formation, enhancing the overall stability of the second hole transport layer and thus achieving better device operational stability. In other words, the perovskite solar cell of this application can simultaneously possess high photoelectric conversion efficiency and device stability. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell provided in one embodiment of this application.

[0021] Explanation of reference numerals in the attached figures:

[0022] 10-Substrate; 20-Transparent conductive layer; 30-First hole transport layer; 40-Second hole transport layer; 50-Perovskite layer; 60-Electron transport layer; 70-Hole blocking layer; 80-Electrode. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] In the accompanying drawings, the thicknesses of layers, films, regions, substrates, etc., are exaggerated for clarity. Throughout the specification, the same reference numerals refer to the same elements. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it may be directly on the other element or there may be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0029] Reference Figure 1As shown, one embodiment of this application provides a perovskite solar cell, including a first hole transport layer 30, a second hole transport layer 40, and a perovskite layer 50 stacked together, wherein the second hole transport layer 40 is located between the first hole transport layer 30 and the perovskite layer 50; the material of the first hole transport layer 30 includes nickel oxide; the raw materials of the second hole transport layer 40 include self-assembled monolayer materials and additives; the additives include ester compounds having phosphate groups and multiple alkenyl groups.

[0030] In the aforementioned perovskite solar cell, the raw materials for the second hole transport layer 40 include a self-assembled monolayer material and additives. The additives include ester compounds containing phosphate groups and multiple alkenyl groups. Introducing ester compounds containing phosphate groups and multiple alkenyl groups as additives into the self-assembled monolayer material allows the additives to anchor to the nickel oxide of the first hole transport layer 30 via the phosphate groups during film formation. The additives and the self-assembled monolayer material form a competitive coordination anchoring mechanism. The addition of additives, without affecting the film formation of the self-assembled monolayer material, can achieve more complete coordination passivation of defects on the nickel oxide surface, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0031] Furthermore, multiple alkenyl groups in the additive molecules can be cross-linked during film formation, enhancing the overall stability of the second hole transport layer 40 and thus achieving better device operational stability. It is understood that the additive can achieve cross-linking through the addition of an initiator or through ultraviolet irradiation, forming a three-dimensional network structure and reducing reverse dissolution of the additive during the preparation of the perovskite layer. Therefore, the perovskite solar cell of this application can simultaneously possess high photoelectric conversion efficiency and device stability.

[0032] In some embodiments, the additive is an ester compound having a phosphate group and multiple alkenyl groups.

[0033] In some embodiments, the additive includes at least one of triallyl phosphate, diallyl phosphate, diallyl methyl phosphate, and diallyl ethyl phosphate.

[0034] In some embodiments, the additive is at least one of triallyl phosphate and diallyl phosphate.

[0035] In some embodiments, the mass ratio of additives to self-assembled monolayer materials in the second hole transport layer 40 is 1:(10~100).

[0036] Within the aforementioned mass ratio range of additives and self-assembled monolayer materials, it is convenient to achieve a better passivation effect of the second hole transport layer 40 on the defects of the first hole transport layer 30. If the mass ratio of additives to self-assembled monolayer materials is too low, i.e., the amount of additives is too small, the improvement in the passivation effect of the second hole transport layer 40 on the defects of the first hole transport layer 30 may not be significant; if the mass ratio of additives to self-assembled monolayer materials is too high, i.e., the amount of additives is too large, it may affect the film formation effect of the self-assembled monolayer materials, thereby affecting the photoelectric conversion efficiency of the perovskite solar cell. Optionally, in the second hole transport layer 40, the mass ratio of additives to self-assembled monolayer materials is 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, or 1:100, or the mass ratio of additives to self-assembled monolayer materials in the second hole transport layer 40 can also be within the range between any two of the above mass ratios.

[0037] In some embodiments, the self-assembled monolayer material includes a carbazole-based self-assembled monolayer material.

[0038] In some embodiments, the self-assembled monolayer materials include [4-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphonic acid (Ph-4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)phenyl]phosphonic acid (Me-PhpPACz), [4-(9H-carbazole-9-yl)benzyl]phosphonic acid (4-(carbazole-9-yl)benzylphosphonic acid) (4PABCz), [2-(9H-carbazole-9-yl)benzyl]phosphonic acid (2-(carbazole-9-yl)benzylphosphonic acid) (2PABCz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-Ph-4PACz), [4-(3,6-dibromo ... [9-yl)butyl]phosphonic acid (Br-Ph-4PACz), [4-(3,6-difluoro-9H-carbazole-9-yl)butyl]phosphonic acid (F-Ph-4PACz), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [2-(3,6-dichloro-9H-carbazole-9-yl)ethyl]phosphonic acid (Cl-2PACz), [2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid (Br-2PACz), [2-(3,6-diiodo-9H-carbazole-9-yl)ethyl]phosphonic acid (I-2PACz), [4-(9H-carbazole-9-yl)ethyl]phosphonic acid (I-2PACz), [4-(9H-carbazole-9-yl)ethyl]phosphonic acid (I-2PACz), [4-(9H-carbazole-9-yl)ethyl]phosphonic acid (B-Ph-4PACz), [4-(3,6-difluoro-9H-carbazole-9-yl)ethyl]phosphonic acid (B-Ph-4 ...3,6-difluoro-9H-carbazole-9-yl)ethyl]phosphonic acid (B-Ph-4PACz), [4-(3,6-difluoro-9H-carbazole-9-yl)ethyl]phosphonic acid (B-Ph-4PA Phosphonic acid [4PACz], [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [4-(3-bromo-6-methoxy-9H-carbazole-9-yl)butyl]phosphonic acid (BrMeO-4PACz), [4-(3-bromo-6-methoxy-9H-carbazole-9-yl)phenyl]phosphonic acid (BrMeOPh-4PACz), [4-(3-methoxy-6-fluoro-9H-carbazole-9-yl)butyl]phosphonic acid (MeOF-Ph-4PACz), [2-(dibenzofuran-9-yl)ethyl]phosphonic acid Phosphonic acid (2PADCB), [4-(dibenzofuran-9-yl)butyl]phosphonic acid (4PADCB), [4-(3,6-dimethoxy-dibenzofuran-9-yl)butyl]phosphonic acid (MeO-4PADCB), [4-(3,6-dibromo-dibenzofuran-9-yl)butyl]phosphonic acid (Br-4PADCB), [2-(9,9-dimethylacridin-10-yl)ethyl]phosphonic acid (DMACPA), [4-(phenothiazine-10-yl)butyl]phosphonic acid (4PAPTZ), [4-(3,7-dibromophenothiazine-10-yl)butyl]phosphonic acid (Br-4PAPTZ), [4-(phenothiazine-10-yl)butyl]phosphonic acid (4PAPXZ), [4-(3,At least one of the following: [7-dibromophenoxazine-10-yl)butyl]phosphonic acid (Br-4PAPXZ), [4-(N-methylphenthiazine-10-yl)butyl]phosphonic acid (MPA-CPA), [2-(9,9-dimethylindocarbazole-12-yl)ethyl]phosphonic acid (DMICPA), [2-(indocarbazole-12-yl)ethyl]phosphonic acid (PAInCz), [4-(dicarbazole-9-yl)butyl]phosphonic acid (DCZ-4P), and [4-(diphenylamino)butyl]phosphonic acid (D4PA).

[0039] In some embodiments, the thickness of the second hole transport layer 40 is 1 nm to 5 nm.

[0040] Optionally, the thickness of the second hole transport layer 40 is 1 nm, 2 nm, 3 nm, 4 nm or 5 nm, or the thickness of the second hole transport layer 40 may be within any two of the above thicknesses.

[0041] In some embodiments, the material of the first hole transport layer 30 is nickel oxide.

[0042] Refer again Figure 1 As shown, in some embodiments, a perovskite solar cell includes a substrate 10, a transparent conductive layer 20, a first hole transport layer 30, a second hole transport layer 40, a perovskite layer 50, an electron transport layer 60, and an electrode 80, which are stacked sequentially.

[0043] The perovskite solar cell with the above structure is an inverted perovskite solar cell. The structure of the first hole transport layer 30 and the second hole transport layer 40 in this application can improve the film formation effect of the perovskite layer in an inverted perovskite solar cell, thereby improving the conversion efficiency and stability of the perovskite solar cell.

[0044] In some embodiments, the perovskite solar cell further includes a hole blocking layer 70 located between the electron transport layer 60 and the electrode 80.

[0045] In some embodiments, the substrate 10 includes at least one of glass, sapphire, PET, and PEN.

[0046] In some embodiments, the transparent conductive layer 20 includes at least one of FTO, ITO, and AZO.

[0047] In some embodiments, the perovskite layer 50 comprises a material having the following general chemical formula: ABX3, wherein A includes FA. + MA + Cs + and Rb + At least one of them, B includes Pb 2+Sn 2+ and Sr 2+ At least one of them, X includes Cl - ,Br - and I - At least one of them.

[0048] In some embodiments, the electron transport layer 60 includes at least one of TiO2, SnO2, ZnO, PCBM, and fullerenes and their derivatives.

[0049] In some embodiments, the hole blocking layer 70 includes a BCP.

[0050] In some embodiments, electrode 80 includes metal electrode 80.

[0051] In some embodiments, electrode 80 includes at least one of Ag, Au, Al, and Cu.

[0052] Another embodiment of this application provides a method for fabricating a perovskite solar cell, comprising the following steps:

[0053] Self-assembled monolayer materials and additives are dissolved in an organic solvent to obtain a precursor solution. The additives include ester compounds with phosphate groups and multiple alkenyl groups.

[0054] A precursor solution is applied to the surface of a first hole transport layer 30, the material of which includes nickel oxide, to obtain a first precursor film.

[0055] The first precursor film is annealed to prepare a second hole transport layer 40 on the surface of the first hole transport layer 30.

[0056] A perovskite layer 50 is prepared on the surface of the second hole transport layer 40 that is opposite to the first hole transport layer 30.

[0057] During the annealing process, the self-assembled monolayer material and the additives compete for coordination and anchor to nickel oxide. This allows for more complete coordination passivation of defects on the nickel oxide surface without affecting the film formation of the self-assembled monolayer material, thereby improving the photoelectric conversion efficiency of the perovskite solar cell. Simultaneously, multiple alkenyl groups in the additive molecules can achieve cross-linking, enhancing the overall stability of the second hole transport layer 40, thus achieving better device operational stability.

[0058] In some embodiments, the first precursor film is prepared by spin-coating a precursor solution.

[0059] In some of these embodiments, the organic solvent includes at least one of ethanol and propanol.

[0060] In some embodiments, the concentration of the self-assembled monolayer material in the precursor solution is 0.1 mg / mL to 1 mg / mL; and the concentration of the additive is 0.001 mg / mL to 0.1 mg / mL.

[0061] Within the range of concentrations of the self-assembled monolayer material and the additives in the aforementioned precursor solution, it is convenient to achieve a better film-forming effect of the second hole transport layer 40 and a better passivation effect on defects in nickel oxide.

[0062] Optionally, the concentration of the self-assembled monolayer material in the precursor solution is 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, 0.5 mg / mL, 0.6 mg / mL, 0.7 mg / mL, 0.8 mg / mL, 0.9 mg / mL, or 1 mg / mL. Alternatively, the concentration of the self-assembled monolayer material in the precursor solution may be within any two of the above concentrations.

[0063] Optionally, the concentration of the additive in the precursor solution is 0.001 mg / mL, 0.002 mg / mL, 0.005 mg / mL, 0.01 mg / mL, 0.02 mg / mL, 0.05 mg / mL, 0.08 mg / mL, or 0.1 mg / mL, or the concentration of the additive in the precursor solution may be within any two of the above concentrations.

[0064] In some embodiments, the annealing temperature is 80°C to 120°C; the annealing time is 5 min to 20 min.

[0065] Within the temperature and time range of the above annealing treatment, the second hole transport layer 40 can achieve better cross-linking and film formation effects.

[0066] Optionally, the annealing temperature is 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, or 120°C, or the annealing temperature may be within any two of the above temperatures.

[0067] Optionally, the annealing time can be 5 min, 8 min, 10 min, 12 min, 15 min, 18 min or 20 min, or the annealing time can be within any two of the above times.

[0068] In some embodiments, the method for fabricating a perovskite solar cell includes the following steps:

[0069] A substrate 10 is provided, and a transparent electrode 80 is provided on the surface of the substrate 10;

[0070] A first hole transport layer 30 is fabricated on the transparent electrode 80;

[0071] A second hole transport layer 40 is fabricated on the first hole transport layer 30;

[0072] A perovskite layer 50 is prepared on the second hole transport layer 40;

[0073] An electron transport layer 60, a hole blocking layer 70, and an electrode 80 are sequentially stacked on the perovskite layer 50.

[0074] In some embodiments, the first hole transport layer 30 is prepared by spin-coating a solution of nickel oxide nanoparticles.

[0075] Another embodiment of this application provides an electrical device, including a perovskite solar cell of any one of the above claims or a perovskite solar cell prepared by any one of the above claims; the perovskite solar cell is used to supply power to the electrical device.

[0076] The following are specific examples:

[0077] Example 1

[0078] The perovskite solar cell in Example 1 has the following structure from bottom to top: glass / ITO / NiO x / Ph-4PACz and Triallyl Phosphate / Cs 0.1 FA 0.9 PbI3 / PCBM / BCP / Ag.

[0079] Methods for fabricating perovskite solar cells:

[0080] (1) The indium tin oxide conductive glass was ultrasonically cleaned for 15 minutes with deionized water, acetone and isopropanol respectively, and then placed in a drying oven at 75°C for drying. The dried ITO conductive glass substrate was placed in an ultraviolet ozone machine for 25 minutes to remove organic impurities on its surface and optimize its surface wettability.

[0081] (2) The first hole transport layer 30 was prepared by spin-coating a nickel oxide nanoparticle solution; Ph-4PACz and triallyl phosphate were dissolved in ethanol to prepare a precursor solution, wherein the concentration of Ph-4PACz was 0.5 mg / mL and the concentration of triallyl phosphate was 0.025 mg / mL; 30 μL of the above precursor solution was taken and spin-coated on the nickel oxide layer at 3000 rpm for 30 s, and then heated and annealed at 100 °C for 10 min on a hot stage. At the same time, 365 nm ultraviolet light was irradiated for 90 s at the beginning of the annealing process to complete the crosslinking, and a second hole transport layer 40 with a thickness of 3 nm was obtained.

[0082] (3) Preparation of perovskite precursor solution: Mix three raw material powders, FAI, PbI2 and CsI and 10% of the additive MACl of PbI2, add them to 1 mL of DMF and NMP (volume ratio of 4:1) to dissolve and obtain a 1.5 mol / L perovskite precursor solution.

[0083] Preparation of perovskite layer 50: In a nitrogen glove box, 30 μL of perovskite precursor solution was coated on the surface of the second hole transport layer 40, and then spin-coated at 1000 rpm for 10 s, then at 5000 rpm for 30 s. At the same time, 125 μL of chlorobenzene was rapidly added while spin-coating at 5000 rpm for 25 s. Then, it was placed on a hot stage and annealed at 100℃ for 40 min to obtain a perovskite light-absorbing layer with a thickness of 500 nm.

[0084] (4) Dissolve 20 mg of methyl [6,6]-phenyl-C61-butyrate (PCBM) in 1 mL of chlorobenzene and stir at room temperature to obtain a PCBM solution; take 30 μL of PCBM solution and coat it on the surface of the perovskite layer 50, and then spin coat it at 3000 rpm for 60 s to form an electron transport layer 60 with a thickness of 30 nm.

[0085] (5) Dissolve 0.5 mg of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in 1 mL of isopropanol and stir at room temperature to obtain hole blocking layer 70 solution; take 40 μL of hole blocking layer 70 solution and drop it onto the surface of electron transport layer 60, and then spin coat at 5000 rpm for 35 s to obtain hole blocking layer 70 with a thickness of 6 nm;

[0086] (6) Transfer the ITO conductive glass with hole blocking layer 70, electron transport layer 60, perovskite layer 50 and hole transport layer to a vacuum coating instrument, and wait for the vacuum degree to reach 3×10 -4 Silver electrode 80 is deposited by vapor deposition at Pa, forming a silver electrode 80 with a thickness of 100 nm on the hole blocking layer 70, thus obtaining electrode layer 80.

[0087] Example 2

[0088] The structure and preparation method of the perovskite solar cell in Example 2 are basically the same as those in Example 1, except that the triallyl phosphate in step (2) is replaced with diallyl phosphate.

[0089] Example 3

[0090] The structure and preparation method of the perovskite solar cell in Example 3 are basically the same as those in Example 1. The only difference is that the concentration of triallyl phosphate in step (2) is replaced with 0.05 mg / mL, that is, the additive accounts for 10% of the mass percentage of the self-assembled monolayer material.

[0091] Example 4

[0092] The structure and preparation method of the perovskite solar cell in Example 4 are basically the same as those in Example 1. The only difference is that the concentration of triallyl phosphate in step (2) is replaced with 0.005 mg / mL, that is, the additive accounts for 1% of the mass percentage of the self-assembled monolayer material.

[0093] Example 5

[0094] The structure and preparation method of the perovskite solar cell in Example 5 are basically the same as those in Example 1. The only difference is that the concentration of triallyl phosphate in step (2) is replaced with 0.1 mg / mL, that is, the additive accounts for 20% of the mass percentage of the self-assembled monolayer material.

[0095] Example 6

[0096] The structure and preparation method of the perovskite solar cell in Example 6 are basically the same as those in Example 1. The only difference is that the concentration of triallyl phosphate in step (2) is replaced with 0.001 mg / mL, that is, the additive accounts for 0.2% of the mass percentage of the self-assembled monolayer material.

[0097] Example 7

[0098] The structure and preparation method of the perovskite solar cell in Example 7 are basically the same as those in Example 1. The only difference is that the spin coating parameters are changed in step (2) so that the thickness of the second hole transport layer 40 is 1 nm.

[0099] Example 8

[0100] The structure and preparation method of the perovskite solar cell in Example 8 are basically the same as those in Example 1. The only difference is that the spin coating parameters are changed in step (2) so that the thickness of the second hole transport layer 40 is 5 nm.

[0101] Comparative Example 1

[0102] The structure and preparation method of the perovskite solar cell in Comparative Example 1 are basically the same as those in Example 1. The only difference is that in step (2), propyl phosphate is not added, that is, the material of the second hole transport layer 40 is only Ph-4PACz.

[0103] The perovskite solar cells prepared in Examples 1-8 and Comparative Example 1 were subjected to photoelectric performance and stability tests. The stability test was conducted by photothermal aging in a nitrogen atmosphere under the following conditions: AM1.5G standard solar spectrum and irradiance of 100 mW / cm². 2 The test was conducted at 85℃ for 24 hours. The results are shown in Table 1 below, where the ratios in the material composition are by mass.

[0104] Table 1

[0105]

[0106] Comparing the test results of Examples 1-8 and Comparative Example 1, in Comparative Example 1, the material of the second hole transport layer 40 is only Ph-4PACz, and the PCE of the perovskite solar cell is 21.76%, with an efficiency degradation rate of 23.6% after stability testing. In Examples 1-8, additives containing ester compounds with phosphate groups and multiple alkenyl groups were added, and the PCE of the perovskite solar cell was 21.83%~23.00%, with a degradation rate of 3.4%~16.6%. Compared with Comparative Example 1, both examples show a significantly improved PCE and a significantly reduced degradation rate. That is, the perovskite solar cell of this application can solve the problem of insufficient passivation of nickel oxide surface defects by self-assembled monolayer materials, thereby achieving both high photoelectric conversion efficiency and device stability.

[0107] Furthermore, comparing Examples 1 and 3-6, compared to Examples 5 and 6, the percentage of additives in the self-assembled monolayer material in Examples 1, 3 and 4 is in the range of 1% to 10%, which facilitates the perovskite solar cell to have both high photoelectric conversion efficiency and device stability.

[0108] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0109] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A perovskite solar cell, characterized in that, The device includes a first hole transport layer, a second hole transport layer, and a perovskite layer stacked together, wherein the second hole transport layer is located between the first hole transport layer and the perovskite layer; the material of the first hole transport layer includes nickel oxide; the raw materials of the second hole transport layer include self-assembled monolayer materials and additives; the additives include ester compounds having phosphate groups and multiple alkenyl groups.

2. The perovskite solar cell according to claim 1, characterized in that, The additive includes at least one of triallyl phosphate, diallyl phosphate, diallyl methyl phosphate, and diallyl ethyl phosphate.

3. The perovskite solar cell according to claim 1, characterized in that, In the second hole transport layer, the mass ratio of the additive to the self-assembled monolayer material is 1:(10~100).

4. The perovskite solar cell according to claim 1, characterized in that, The self-assembled monolayer material includes at least one of Ph-4PACz, Me-PhpPACz, 4PABCz, 2PABCz, MeO-Ph-4PACz, Br-Ph-4PACz, F-Ph-4PACz, 2PACz, MeO-2PACz, Cl-2PACz, Br-2PACz, I-2PACz, 4PACz, MeO-4PACz, Me-4PACz, BrMeO-4PACz, BrMeOPh-4PACz, 2PADCB, 4PADCB, MeO-4PADCB, Br-4PADCB, DMACPA, 4PAPTZ, Br-4PAPTZ, 4PAPXZ, Br-4PAPXZ, MPA-CPA, DMICPA, PAInCz, DCZ-4P, D4PA, and MeOF-Ph-4PACz.

5. The perovskite solar cell according to claim 1, characterized in that, The thickness of the second hole transport layer is 1nm~5nm.

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that, The perovskite solar cell includes a substrate, a transparent conductive layer, a first hole transport layer, a second hole transport layer, a perovskite layer, an electron transport layer, and electrodes, which are stacked sequentially.

7. A method for preparing a perovskite solar cell, characterized in that, Includes the following steps: A precursor solution is obtained by dissolving a self-assembled monolayer material and an additive in an organic solvent, wherein the additive includes an ester compound having a phosphate group and multiple alkenyl groups. The precursor solution is applied to the surface of a first hole transport layer, wherein the material of the first hole transport layer includes nickel oxide, to obtain a first precursor film. The first precursor film is annealed to prepare a second hole transport layer on the surface of the first hole transport layer. A perovskite layer is prepared on the surface of the second hole transport layer that is opposite to the first hole transport layer.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that, In the precursor solution, the concentration of the self-assembled monolayer material is 0.1 mg / mL to 1 mg / mL; the concentration of the additive is 0.001 mg / mL to 0.1 mg / mL.

9. The method for preparing a perovskite solar cell according to claim 7, characterized in that, The annealing temperature is 80℃~120℃; the annealing time is 5min~20min.

10. An electrical device, characterized in that, The perovskite solar cell includes the perovskite solar cell prepared by any one of claims 1 to 6 or the perovskite solar cell prepared by any one of claims 7 to 9; the perovskite solar cell is used to supply power to the electrical device.

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