Hole transport modification layer, perovskite cell and preparation method and application thereof

Abstract

The invention discloses a hole transport modification layer, a perovskite cell and a preparation method and application thereof, and relates to the technical field of photovoltaics. A self-assembly molecular material and a transport layer passivation layer are formed on a hole transport layer, and the thickness relationship between the hole transport layer and the transport layer passivation layer is optimized, so that the transport layer passivation layer can better modify the interface between the hole transport layer and perovskite; therefore, the short-circuit current density and the fill factor of the perovskite solar cell are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and more specifically, to hole transport modification layers, perovskite solar cells, their preparation methods, and applications. Background Technology

[0002] Nickel oxide, an inorganic p-type semiconductor, is commonly used as the hole transport layer in inverted and tandem perovskite solar cells due to its low fabrication cost, stability, and scalability. However, the nickel oxide surface contains oxygen vacancies and uncoordinated metal ion defects, while the lower surface of the perovskite material exhibits submicron-level defects. The interaction between nickel oxide and the perovskite layer can also lead to interfacial reactions, causing nonradiative recombination at the interface. These phenomena adversely affect device stability and pose obstacles to achieving high-efficiency and highly stable inverted perovskite solar cells.

[0003] To address the interface issues in nickel oxide / perovskite heterojunctions, self-assembled monolayers (SAMs) are commonly used to modify and passivate the buried interface. However, SAMs are not effective at passivating defects at the bottom of the perovskite layer and can even reduce the short-circuit current density and fill factor of perovskite solar cells, leading to a decrease in photoelectric conversion efficiency.

[0004] Therefore, it is urgent to modify the interface between the hole transport layer and the perovskite layer to improve the short-circuit current density and fill factor of perovskite solar cells, thereby improving the photoelectric conversion efficiency of perovskite solar cells.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a hole transport modification layer, a perovskite solar cell, a method for preparing a perovskite solar cell, and a photovoltaic module, with the aim of improving the short-circuit current density and fill factor of perovskite solar cells.

[0007] This invention is implemented as follows:

[0008] In a first aspect, the present invention provides a hole transport modification layer, comprising a hole transport layer and a transport layer passivation layer deposited on the hole transport layer;

[0009] The passivation layer of the transport layer contains self-assembled molecular materials;

[0010] The thickness of the passivation layer in the transport layer ranges from 0.1 nm to 4.0 nm.

[0011] In an optional embodiment, the thickness of the passivation layer of the transport layer is 0.2 nm-1.5 nm; preferably 0.35 nm-0.75 nm.

[0012] Preferably, the thickness of the hole transport layer is 10nm-30nm.

[0013] In an optional embodiment, the passivation layer of the transport layer further contains a hydrophilic functional material, which contains a hydrophilic polar group selected from at least one of hydroxyl, carboxyl, amide, amino, aldehyde and carbonyl groups.

[0014] Preferably, the hydrophilic functional material contains amino groups and halide ions, and its general chemical structure formula is as follows:

[0015]

[0016] In the formula, n is an integer from 1 to 4, and X is selected from any one of fluorine, chlorine, bromine and iodine;

[0017] Preferably, the hydrophilic functional material is phenylethyl iodide.

[0018] In an optional embodiment, the mass ratio of the self-assembled molecular material to the hydrophilic functional material is (0.5-30):1, preferably (5-15):1;

[0019] Preferably, the general chemical structural formula of the self-assembled molecular material is as follows:

[0020]

[0021] In the formula, n is an integer from 1 to 4; R1 and R2 are hydrogen or methoxy groups, and R1 and R2 are the same group;

[0022] More preferably, the self-assembled molecular material is selected from any one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid; more preferably, the self-assembled molecular material is [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid;

[0023] Preferably, the hole transport layer contains any one of the following materials: nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid;

[0024] Preferably, the hole transport layer contains nickel oxide.

[0025] Secondly, the present invention also provides a perovskite solar cell, including a substrate, on which a hole transport modification layer as described in any of the above embodiments is formed. The hole transport modification layer includes a hole transport layer and a transport layer passivation layer deposited on the hole transport layer, wherein the hole transport layer is located between the substrate and the transport layer passivation layer.

[0026] In an optional embodiment, a perovskite layer is disposed on the transport layer passivation layer;

[0027] Preferably, the perovskite layer contains a material with an ABX3 structure;

[0028] Wherein, A represents the first cation, which is selected from Rb. + Na + K + Ca 2+ Ba 2+ Cs + HN=CHNH 3+ and CH3NH 3+ At least one of them;

[0029] B represents the second cation, which is selected from Ti. 4+ 、Nb 5+ Mn 4+ Fe 3+ Ta 5+ ,Th 4+ Zr 4+ Pb 2+ 、Sr 2+ Sn 2+ and Cu 2+ At least one of them;

[0030] X is selected from halogen anions, O 2- and S 2- At least one of the following; halide anions include F - Cl - ,Br - and I - ;

[0031] More preferably, the material having the ABX3 structure is selected from CH3NH3PbI3, HN=CHNH3PbI3, Cs x ((HN=CHNH3) y (CH3NH3) 1-y ) 1-x Pb(I z Br 1-z 3. Cs x((HN=CHNH3)y(CH3NH3) 1-y ) 1-x Pb(I z Cl 1-z At least one of the following three conditions must be met: x, y, and z satisfy: 0 < x ≤ 0.25, 0.5, ... <y≤1、0.75≤z<1;

[0032] More preferably, the thickness of the perovskite layer is 900nm-1500nm.

[0033] In an optional embodiment, a perovskite passivation layer, an electron transport layer, and a metal electrode are sequentially disposed on the perovskite layer.

[0034] Preferably, the perovskite passivation layer contains at least one of hydroxyl, carboxyl, amide, amino, and aldehyde groups; preferably, the thickness of the perovskite passivation layer is 1 nm-20 nm.

[0035] Preferably, the electron transport layer contains at least one of fullerene or its derivative, copper bath, tin oxide, and titanium oxide; preferably, the thickness of the electron transport layer is 1 nm-50 nm.

[0036] Preferably, the metal electrode is selected from at least one of silver electrode, gold electrode, copper electrode, aluminum electrode, carbon electrode, silicon carbide electrode and transparent conductive oxide electrode; preferably, the thickness of the metal electrode is 10nm-350nm.

[0037] Thirdly, the present invention provides a method for preparing a perovskite solar cell according to any of the foregoing embodiments, comprising: sequentially forming a hole transport layer and a transport layer passivation layer on a substrate.

[0038] In an optional embodiment, the preparation process of the passivation layer of the transport layer includes: mixing self-assembled molecular materials, hydrophilic functional materials and solvents to obtain a passivation layer solution, coating the passivation layer solution onto the hole transport layer and annealing it;

[0039] Preferably, the concentration of the passivation layer solution is 0.1 mg / mL to 5.0 mg / mL;

[0040] Preferably, the solvent is selected from at least one of dimethyl sulfoxide, N,N-dimethylformamide, isopropanol, water, and ethanol;

[0041] Preferably, the method further includes sequentially forming a perovskite layer, a perovskite passivation layer, an electron transport layer, and a metal electrode on the transport layer passivation layer.

[0042] Fourthly, the present invention provides a photovoltaic module, including any of the perovskite cells in the foregoing embodiments or perovskite cells prepared by any of the preparation methods in the foregoing embodiments.

[0043] The present invention has the following beneficial effects: By forming a hole transport layer containing self-assembled molecular materials and a transport layer passivation layer on the hole transport layer, and by optimizing the thickness relationship between the hole transport layer and the transport layer passivation layer, the transport layer passivation layer can better modify the interface between the hole transport layer and the perovskite, thereby significantly improving the short-circuit current density and fill factor of the perovskite solar cell. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a structural diagram of a perovskite solar cell provided in an embodiment of the present invention;

[0046] Figure 2 A flowchart illustrating the modification of the nickel oxide / perovskite layer interface using a mixed solution of PEAI (phenylethyl ammonium iodide) and SAM (self-assembled monolayer) materials;

[0047] Figure 3 The results of using a spin coating model to simulate and obtain wet film thickness under different processes are shown in the figure.

[0048] Figure 4 The image shows the IV test results of the product obtained in Example 1.

[0049] Icons: 100 - Substrate; 200 - Hole transport layer; 300 - Transport layer passivation layer; 400 - Perovskite layer; 500 - Perovskite passivation layer; 600 - Electron transport layer; 700 - Metal electrode. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0051] To address the interface issues in nickel oxide / perovskite heterojunctions, existing technologies often employ self-assembled monolayers (SAMs) to modify and passivate the buried interface. However, the inventors have discovered several limitations of SAMs: firstly, the hydrophobic nature of the materials used in SAM layers (such as Me-4PACz) makes it difficult to form a uniform perovskite layer; secondly, the Me-4PACz end groups (carbazole cores) cannot strongly passivate defects at the bottom of the perovskite layer, resulting in a high defect density at the hole transport layer and perovskite interface. This leads to an increased recombination rate on the lower perovskite surface, reducing the short-circuit current density and fill factor of the perovskite solar cell.

[0052] Therefore, this invention optimizes the thickness relationship between the hole transport layer and the passivation layer, enabling the passivation layer to better modify the interface between the hole transport layer and the perovskite, thereby significantly improving the short-circuit current density and fill factor of the perovskite solar cell.

[0053] This invention provides a hole transport modification layer, comprising a hole transport layer and a transport layer passivation layer deposited on the hole transport layer, wherein the transport layer passivation layer contains self-assembled molecular materials; the thickness of the transport layer passivation layer is 0.1 nm-4.0 nm. Controlling the thickness of the transport layer passivation layer within the above range is preferable, as this range can improve the short-circuit current density and fill factor of the perovskite solar cell.

[0054] Specifically, the thickness of the hole transport layer can be 10nm, 13nm, 15nm, 18nm, 20nm, 23nm, 25nm, 28nm, 30nm, etc., and the thickness of the passivation layer of the transport layer can be 0.10nm, 0.2nm, 0.30nm, 0.35nm, 0.40nm, 0.50nm, 0.60nm, 0.70nm, 0.75nm, 1.00nm, 1.50nm, 2.00nm, 2.50nm, 3.00nm, 3.50nm, 4.00nm, etc.

[0055] In a preferred embodiment, the thickness of the passivation layer of the transport layer is 0.2 nm-1.5 nm, preferably 0.35 nm-0.75 nm; the thickness of the hole transport layer is 10 nm-30 nm. Controlling the thickness of the hole transport layer and the passivation layer within the above range can further improve the short-circuit current density and fill factor of the perovskite solar cell.

[0056] In some embodiments, the transport layer passivation layer contains self-assembled molecular materials and hydrophilic functional materials. The hydrophilic functional materials contain hydrophilic polar groups, which are selected from at least one of hydroxyl, carboxyl, amide, amino, aldehyde, and carbonyl groups. By introducing any one or more of the above hydrophilic polar groups, the hydrophobicity of SAM and the problem of insufficient passivation ability at the bottom of the perovskite layer are improved.

[0057] It should be noted that the inventors optimized the material selection for modifying the hole transport layer, introduced hydrophilic functional materials on the basis of self-assembled molecular materials, improved the hydrophobicity of SAM and the insufficient ability to passivate the bottom of the perovskite layer, modified the interface between nickel oxide and perovskite, passivated the defects at the bottom of the perovskite layer, improved the perovskite coverage, and improved battery performance.

[0058] In some embodiments, the hydrophilic functional material contains amino groups and halide ions, and its general chemical structural formula is as follows:

[0059]

[0060] In the formula, n is an integer from 1 to 4, such as 1, 2, 3, 4, etc.; X is selected from any one of fluorine, chlorine, bromine, and iodine, and X can be any one or more of the above. Utilizing the amino and halide ions in hydrophilic functional materials can better improve the hydrophobicity of SAM, enhance the passivation effect on the bottom of the perovskite layer, and better modify the interface between nickel oxide and perovskite.

[0061] In a preferred embodiment, the hydrophilic functional material is phenylethyl iodide (PEAI), with the following structure:

[0062]

[0063] The amino and iodide ions of PEAI can effectively passivate the A-site ion vacancies and halogen vacancies on the perovskite surface, forming a more stable 2D perovskite on the 3D perovskite surface. Furthermore, mixing it with SAM can improve its hydrophobicity, making it easier to form a uniform perovskite layer.

[0064] In some embodiments, the general chemical structure of a self-assembled molecular material (SAM) is as follows:

[0065]

[0066] In the formula, n is an integer from 1 to 4, such as 1, 2, 3, 4, etc.; R1 and R2 are hydrogen or methoxy groups, and R1 and R2 are the same group.

[0067] In a preferred embodiment, the self-assembled molecular material (SAM) is selected from any one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz). The SAM can be any one or more of the above.

[0068] Specifically, the structural formula of 2PACz is as follows:

[0069]

[0070] The structural formula of MeO-2PACz is as follows:

[0071]

[0072] The structural formula of 4PACz is as follows:

[0073]

[0074] More preferably, SAM is [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid (Me-4PACz). Using PEAI and Me-4PACz as the materials for the transport layer passivation layer can further improve the conversion efficiency of the battery.

[0075] Furthermore, the mass ratio of the self-assembled molecular material to the hydrophilic functional material is (0.5-30):1, such as 0.5:1, 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, etc., preferably (5-15):1. By optimizing the mass ratio of the self-assembled molecular material to the hydrophilic functional material, the hole transport layer and the cross-section of the perovskite can be better modified, and the defects at the bottom of the perovskite layer can be passivated.

[0076] Preferably, the self-assembled molecular material is selected from any one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid; more preferably, the self-assembled molecular material is [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid.

[0077] In some embodiments, the hole transport layer contains any one of the following materials: nickel oxide (NIO), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), [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-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz). The hole transport layer material can be any one or more of the above. Preferably, the hole transport layer contains nickel oxide, and NiOx is preferred as the material for the hole transport layer, as it can better complement the passivation layer of the transport layer and modify the interface between nickel oxide and perovskite.

[0078] like Figure 1 As shown, this embodiment of the invention also provides a perovskite solar cell, including a substrate 100, on which a hole transport modification layer provided in this embodiment of the invention is formed. The hole transport modification layer includes a hole transport layer 200 and a transport layer passivation layer 300 deposited on the hole transport layer 200. The hole transport layer 200 is located between the substrate 100 and the transport layer passivation layer 300.

[0079] The substrate 100 can be a general transparent conductive substrate, and the specific material is not limited.

[0080] The materials and thicknesses of the hole transport layer 200 and the hole transport layer passivation layer 300 are described in the specification regarding the hole transport modification layer, and will not be repeated here.

[0081] In some embodiments, a perovskite layer 400 is disposed on the transport layer passivation layer 300. The perovskite layer 400 is the main functional layer of the perovskite solar cell, and its specific material is not limited.

[0082] For example, the perovskite layer 400 contains a material having an ABX3 structure; wherein A represents a first cation, and the first cation is selected from Rb. + Na + K + Ca 2+ Ba 2+ Cs + HN=CHNH 3+ and CH3NH 3+ At least one of the following, the first cation can be any one or more of the above ions; B represents the second cation, which is selected from Ti. 4+ 、Nb 5+ Mn 4+, Fe 3+ , Ta 5 + , Th 4+ , Zr 4+ , Pb 2+ , Sr 2+ , Sn 2+ and Cu 2+ and at least one of the following, the second cation can be any one or several of the above ions; X is selected from halogen anions, O 2- and S 2- and at least one of the following, X can be any one or several of the above anions, and halogen anions include F - , Cl - , Br - , I - etc.

[0083] In some embodiments, the material having the ABX3 structure is selected from CH3NH3PbI3, HN=CHNH3PbI3, Cs x ((HN=CHNH3) y (CH3NH3) 1-y ) 1-x Pb(I z Br 1-z ) 3, Cs x ((HN=CHNH3)y(CH3NH3) 1-y ) 1-x Pb(I z Cl 1-z ) 3, etc. The material in the perovskite layer 400 can be any one or several of the above. Among them, x, y, and z satisfy: 0 < x ≤ 0.25, for example, x can be 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, etc.; 0.5 < y ≤ 1, for example, y can be 0.6, 0.7, 0.8, 0.9, 1.0, etc.; 0.75 ≤ z < 1, for example, it can be 0.75, 0.80, 0.85, 0.90, 0.95, etc.

[0084] Furthermore, the thickness of the perovskite layer is 900 nm - 1500 nm, for example, it can be 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, etc.

[0085] In some embodiments, a perovskite passivation layer 500, an electron transport layer 600, and a metal electrode 700 are sequentially provided on the perovskite layer 400 to form a complete inverted perovskite solar cell structure. The specific materials of the perovskite passivation layer 500, the electron transport layer 600, and the metal electrode 700 are not limited.

[0086] For example, the perovskite passivation layer 500 contains specific groups selected from at least one of hydroxyl (-OH), carboxyl (-COOH), amide, amino (-NH2), and aldehyde (-CHO). The perovskite passivation layer 500 may contain any one or more of these groups, all of which can effectively passivate the perovskite layer 400. The thickness of the perovskite passivation layer is 1 nm-20 nm, such as 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, etc.

[0087] For example, the electron transport layer 600 contains at least one of fullerene or its derivatives, copper bath (BCP), tin oxide (SnO2), and titanium oxide (TiO2). Using any one or more of these materials can achieve good electron transport efficiency. The thickness of the electron transport layer is 1 nm to 50 nm, such as 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, etc.

[0088] For example, the metal electrode 700 is selected from at least one of silver (Ag) electrode, gold (Au) electrode, copper (Cu) electrode, aluminum (Al) electrode, carbon electrode, silicon carbide electrode, and transparent conductive oxide (TCO) electrode. The metal electrode 700 can be any one or more of the above. The thickness of the metal electrode 700 is 10nm-350nm, such as 10nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, etc.

[0089] This invention also provides a method for preparing a perovskite solar cell, comprising: sequentially forming a hole transport layer 200 and a transport layer passivation layer 300 on a substrate 100. The materials of these two layers can be referred to the above description in the specification, and will not be repeated here.

[0090] The hole transport layer 200 is prepared using either a dry or wet process. Dry processes include vacuum deposition and atomic layer deposition, while wet processes include spraying, slot coating, and spin coating. Preferably, NiOx is used as the material for the hole transport layer 200, and spin coating is used as the deposition method to prepare a NiOx thin film as the hole transport layer 200.

[0091] like Figure 2 As shown, the preparation process of the passivation layer 300 of the transport layer includes: mixing a self-assembled molecular material (SAM, specifically Me-4PACz), a hydrophilic functional material (such as PEAI), and a solvent to prepare a passivation layer solution; coating the passivation layer solution onto the hole transport layer 200 and annealing it. The coating method is not limited and can be spin-coating.

[0092] In some embodiments, the concentration of the passivation layer solution is 0.1 mg / mL to 5.0 mg / mL, such as 0.1 mg / mL, 1.0 mg / mL, 2.0 mg / mL, 3.0 mg / mL, 4.0 mg / mL, 5.0 mg / mL, etc. The concentration of the passivation layer solution refers to the total concentration of the self-assembled molecular material and the hydrophilic functional material.

[0093] Furthermore, the type of solvent used to prepare the passivation layer solution is not limited, as long as it can dissolve the two raw materials well. It can be dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), isopropanol (IPA), water, ethanol, etc., specifically any one or more of the above.

[0094] In some embodiments, the preparation method provided in this invention further includes sequentially forming a perovskite layer 400, a perovskite passivation layer 500, an electron transport layer 600, and a metal electrode 700 on the transport layer passivation layer 300. The materials and thicknesses of the above layers can be referred to the description in the specification above, and will not be repeated here.

[0095] The perovskite passivation layer 500 can be produced using either a dry or wet process. Dry processes can include vacuum coating, atomic layer deposition, etc., while wet processes can include spraying, slot coating, spin coating, etc.

[0096] Similarly, the electron transport layer 600 can also be processed using dry or wet processes. Dry processes can include vacuum coating, atomic layer deposition, etc., while wet processes can include spraying, slot coating, spin coating, etc.

[0097] The metal electrode 700 can also be processed using either a dry process or a wet process. Dry processes can include vacuum coating, atomic layer deposition, etc., while wet processes can include screen printing, etc.

[0098] This invention also provides a photovoltaic module, including the perovskite cell provided in this invention, which is beneficial to improving the photoelectric conversion performance of the photovoltaic module.

[0099] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0100] Example 1

[0101] This embodiment provides a method for preparing a perovskite solar cell, including the following steps:

[0102] (1) Clean and treat the ITO conductive glass substrate with an ITO thickness of 100nm with ultraviolet ozone, and set it aside.

[0103] (2) A 20 mg / mL nickel oxide / water solution was spin-coated onto a conductive glass substrate at 4000 rpm. After spin-coating, the substrate was annealed on a hot plate at 100 °C for 10 minutes to form a 20 nm thick nickel oxide hole transport layer.

[0104] (3) Mix Me-4PACz and PEAI and then add ethanol to dissolve them. The solubility of Me-4PACz is 0.455 mg / mL and the concentration of PEAI is 0.045 mg / mL, that is, the mass ratio of Me-4PACz to PEAI is 10:1.

[0105] (4) Spin-coat the solution from step (3) onto nickel oxide at 4000 rpm. After spin-coating, anneal on a hot plate at 100°C for 10 minutes to form a transport layer passivation layer with a thickness of 0.39 nm (i.e., the dry film thickness is 0.39 nm, and the wet film thickness simulated in this embodiment is 1.4 nm).

[0106] (5) Dissolve lead iodide (PbI2) in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) with a DMF:DMSO ratio of 9:1 and a PbI2 concentration of 1.5M.

[0107] (6) Spin-coat the lead iodide solution onto the passivation layer at 1500 rpm, anneal at 70°C for 1 min after spin coating to form a 400 nm lead iodide film, and then cool to room temperature.

[0108] (7) Formamidinium iodide (FAI) was dissolved in isopropanol (IPA) to prepare a solution with a concentration of 90 mg / mL, and methylamine chloride (MACl) was added to make the concentration of methylamine chloride 10 mg / mL.

[0109] (8) Cesium iodide (CsI) was dissolved in isopropanol (IPA) at a concentration of 25 mg / mL and dissolved in a hot table at 100°C.

[0110] (9) Spin-coat the solution from step (7) onto PbI2 at 1500 rpm, add the solution from step (8) dropwise at the 10th second of spin coating, and anneal at 150°C for 20 minutes after spin coating to form a 700 nm perovskite layer.

[0111] (10) Spin-coat a 5 mg / mL PEAI / isopropanol solution onto the perovskite layer at 4000 rpm. After spin-coating, anneal on a hot plate at 100 °C for 10 minutes to form a 2 nm thick perovskite passivation layer.

[0112] (11) A C60 electron transport layer with a thickness of 20 nm was prepared by vapor deposition.

[0113] (12) A copper bath (BCP) electron transport layer with a thickness of 7 nm was prepared by vapor deposition.

[0114] (13) A layer of silver metal electrode with a thickness of 100 nm is deposited on the ITO surface by evaporation through a mask.

[0115] Example 2

[0116] The only difference from Example 1 is that in step (3), the concentration of Me-4PACz is 4.55 mg / mL and the concentration of PEAI is 0.45 mg / mL, that is, the mass ratio of Me-4PACz to PEAI is 10:1. The simulated wet film thickness in this example is 1.5 nm, and the calculated dry film thickness is 3.89 nm.

[0117] Example 3

[0118] The only difference from Example 1 is that in step (3), the concentration of Me-4PACz is 0.0909 mg / mL and the concentration of PEAI is 0.0091 mg / mL, that is, the mass ratio of Me-4PACz to PEAI is 10:1. The simulated wet film thickness in this example is 1.4 nm and the calculated dry film thickness is 0.11 nm.

[0119] Example 4

[0120] The only difference from Example 1 is that in step (3), the concentration of Me-4PACz is 0.91 mg / mL and the concentration of PEAI is 0.09 mg / mL, that is, the mass ratio of Me-4PACz to PEAI is 10:1. The simulated wet film thickness in this example is 1.4 nm and the calculated dry film thickness is 0.71 nm.

[0121] Example 5

[0122] The only difference from Example 1 is that in step (3), the concentration of Me-4PACz is 1.82 mg / mL and the concentration of PEAI is 0.18 mg / mL, that is, the mass ratio of Me-4PACz to PEAI is 10:1. The simulated wet film thickness in this example is 1.5 nm, and the calculated dry film thickness is 1.45 nm.

[0123] Example 6

[0124] The only difference from Example 1 is that in step (8), CsI is replaced with an equal amount of RbBr. Steps (1) to (7) and steps (9) to (12) are the same as in Example 1.

[0125] Example 7

[0126] The only difference from Example 1 is that Me-4PACz is replaced with MeO-2PACz in step (3). Steps (1) to (2) and steps (4) to (12) are the same as in Example 1.

[0127] Example 8

[0128] The only difference from Example 1 is that Me-4PACz is replaced with 2PACz in step (3). Steps (1) to (2) and steps (4) to (12) are the same as in Example 1.

[0129] Example 9

[0130] The only difference from Example 1 is that in step (3), the solubility of Me-4PACz is 0.484 mg / mL and the concentration of PEAI is 0.016 mg / mL, that is, the mass ratio of Me-4PACz to PEAI is 30:1.

[0131] Example 10

[0132] The only difference from Example 1 is that in step (3), the solubility of Me-4PACz is 0.17 mg / mL and the concentration of PEAI is 0.33 mg / mL, that is, the mass ratio of Me-4PACz to PEAI is 0.5:1.

[0133] Comparative Example 1

[0134] Using the same steps (1) to (2) and (5) to (12) as in Example 1, but without adding PEAI in steps (3) to (4), Me-4PACz is dissolved in ethanol at a concentration of 0.5 mg / mL.

[0135] Comparative Example 2

[0136] The same steps (1) to (2) and steps (5) to (12) as in Example 1 were used. In steps (3) to (4), Me-4PACz and PEAI were dissolved in ethanol without mixing. The concentration of Me-4PACz was 0.5 mg / mL and the concentration of PEAI was 1 mg / mL. First, the Me-4PACz solution was spin-coated onto nickel oxide at 4000 rpm / s. After spin-coating, it was annealed on a hot plate at 100°C for 10 minutes. Then, the PEAI solution was spin-coated onto Me-4PACz at 4000 rpm / s. The amount of Me-4PACz and PEAI spin-coated was the same as in Example 1.

[0137] Comparative Example 3

[0138] Using the same steps (1) to (2) and (5) to (12) as in Example 2, but without adding PEAI in steps (3) to (4), Me-4PACz is dissolved in ethanol at a concentration of 0.5 mg / mL.

[0139] Comparative Example 4

[0140] The same steps and methods as in steps (1) to (2) and steps (5) to (12) of Example 2 were adopted. In steps (3) to (4), Me-4PACz and PEAI were dissolved in ethanol without mixing. The solubility of Me-4PACz was 0.5 mg / mL and the concentration of PEAI was 1 mg / mL. First, the Me-4PACz solution was spin-coated onto nickel oxide at 4000 rpm / s. After spin-coating, it was annealed on a hot plate at 100°C for 10 minutes. Then, the PEAI solution was spin-coated onto Me-4PACz at 4000 rpm / s.

[0141] Comparative Example 5

[0142] Using the same steps (1) to (2) and (5) to (12) as in Example 3, but without adding PEAI in steps (3) to (4), MeO-2PACz is dissolved in ethanol, and the concentration of MeO-2PACz is 0.5 mg / mL.

[0143] Comparative Example 6

[0144] Using the same steps (1) to (2) and (5) to (12) as in Example 4, but without adding PEAI in steps (3) to (4), 2PACz is dissolved in ethanol, and the concentration of 2PACz is 0.5 mg / mL.

[0145] Experimental Example 1

[0146] Simulations were performed based on a spin coating model to obtain wet film thicknesses under different processes, such as... Figure 3 The dry film thickness is calculated using the following formula based on the solution concentration and solute density.

[0147]

[0148] h is the dry film thickness, M is the molar mass of the solute, c is the molar concentration, ρ is the solute density, and H is the wet film thickness. The calculated range of dry film thickness for the transport layer passivation layer is given.

[0149] The calculated dry film thickness and performance test results for Examples 1-3 and Comparative Example 1 are shown in Table 1.

[0150] Test method: The fabricated perovskite solar cells were tested using a steady-state light source IV tester to measure the Eff (photoelectric conversion efficiency).

[0151] Table 1. Photoelectric conversion efficiency of perovskite solar cells with different thicknesses of transport layer and passivation layer.

[0152]

[0153]

[0154] As shown in Table 1, Example 1 showed the best performance when the dry film thickness was 0.39 nm, mainly due to the improvement in the short-circuit current density and fill factor of the battery. All examples were superior to Comparative Example 1 without PEAI.

[0155] Experimental Example 2

[0156] The performance of the perovskite solar cells prepared in the test examples and comparative examples was evaluated using the following methods: The perovskite solar cells were tested using a steady-state light source IV meter to measure the Eff (photoelectric conversion efficiency). The test results for Example 1 are shown in the figure below. Figure 4 As shown.

[0157] The perovskite solar cell of Example 1 had an Eff of 19.54%, the perovskite solar cell of Example 6 had an Eff of 14.61%, the perovskite solar cell of Comparative Example 1 had an Eff of 14.08%, the perovskite solar cell of Comparative Example 2 had an Eff of 19.67%, the perovskite solar cell of Comparative Example 3 had an Eff of 12.563%, and the perovskite solar cell of Comparative Example 4 had an Eff of 14.383%. See Tables 2-4 for details.

[0158] Table 2. Photoelectric conversion efficiency of perovskite solar cells made of different materials

[0159]

[0160] Table 3. Photovoltaic conversion efficiency of perovskite solar cells with different ratios of transport layer and passivation layer.

[0161]

[0162] Table 4 Experimental time from hole transport layer to perovskite layer

[0163]

[0164] Table 2 Analysis:

[0165] As can be seen from Example 1 and Comparative Example 1, in the CsI post-treatment system, the battery efficiency is improved by 39% after mixing PEAI and Me-4PACz.

[0166] As can be seen from Example 6 and Comparative Example 3, in the RbBr post-treatment system, the battery efficiency was improved by 16% after mixing PEAI and Me-4PACz.

[0167] Comparisons between Example 1 and Comparative Example 2, and between Example 6 and Comparative Example 4, show that the mixed method of PEAI and Me-4PACz has similar battery efficiency and simpler process than the method of using PEAI and Me-4PACz separately, and the perovskite prepared by the two methods has the same effect.

[0168] As can be seen from the comparison between Example 7 and Comparative Example 5, the efficacy of the mixture of PEAI and SAM is also applicable to MeO-2PACz.

[0169] As can be seen from the comparison between Example 8 and Comparative Example 6, the effect of mixing PEAI and SAM is also applicable to 2PACz.

[0170] The comparison of Examples 1, 7, and 8 shows that the mixture of Me-4PACz and PEAI has the best effect among these three SAMs.

[0171] Table 3 Analysis:

[0172] As can be seen from the comparison of Examples 1, 9 and 10 in Table 3, the mixing ratio of Me-4PACz to PEAI of 10:1 is the most effective.

[0173] Table 4 Analysis:

[0174] As shown in Table 4, the method of using a mixture of SAM and PEAI can significantly reduce the processing time from the hole transport layer to the perovskite layer compared to using SAM and PEAI separately, reducing the time by 7.41% for a single wafer and 13.83% for 10 wafers.

[0175] The embodiments are merely illustrative examples and are not intended to limit the implementation. This preparation method can be applied to perovskite LEDs, including but not limited to single-junction perovskites and multilayer perovskites. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A hole transport modification layer, characterized in that, Includes a hole transport layer and a transport layer passivation layer deposited on the hole transport layer; The passivation layer of the transport layer contains self-assembled molecular materials; The thickness of the passivation layer of the transport layer is 0.1 nm to 4.0 nm.

2. The hole transport modification layer according to claim 1, characterized in that... The thickness of the passivation layer of the transport layer is 0.2nm-1.5nm; preferably 0.35nm-0.75nm. Preferably, the thickness of the hole transport layer is 10nm-30nm.

3. The hole transport modification layer according to claim 1 or 2, characterized in that, The passivation layer of the transport layer also contains a hydrophilic functional material, which contains a hydrophilic polar group selected from at least one of hydroxyl, carboxyl, amide, amino, aldehyde and carbonyl groups. Preferably, the hydrophilic functional material contains amino groups and halide ions, and its general chemical structure formula is as follows: In the formula, n is an integer from 1 to 4, and X is selected from any one of fluorine, chlorine, bromine and iodine; Preferably, the hydrophilic functional material is phenylethyl iodide.

4. The hole transport modification layer according to claim 3, characterized in that... The mass ratio of the self-assembled molecular material to the hydrophilic functional material is (0.5-30):1, preferably (5-15):1; Preferably, the general chemical structural formula of the self-assembled molecular material is as follows: In the formula, n is an integer from 1 to 4; R1 and R2 are hydrogen or methoxy groups, and R1 and R2 are the same group; More preferably, the self-assembled molecular material is selected from any one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid; more preferably, the self-assembled molecular material is [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid; Preferably, the hole transport layer contains any one of the following materials: nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid; more preferably, the hole transport layer contains nickel oxide.

5. A perovskite battery, characterized in that, The device includes a substrate on which a hole transport modification layer according to any one of claims 1-4 is formed, the hole transport modification layer including a hole transport layer and a transport layer passivation layer deposited on the hole transport layer, the hole transport layer being located between the substrate and the transport layer passivation layer.

6. The perovskite solar cell according to claim 5, characterized in that, A perovskite layer is disposed on the passivation layer of the transport layer; Preferably, the perovskite layer contains a material having an ABX3 structure; Wherein, A represents the first cation, which is selected from Rb. + Na + K + Ca 2+ Ba 2+ Cs + HN=CHNH 3+ and CH3NH 3+ At least one of them; B represents the second cation, which is selected from Ti. 4+ 、Nb 5+ Mn 4+ Fe 3+ Ta 5+ ,Th 4+ Zr 4+ Pb 2+ 、Sr 2+ Sn 2+ and Cu 2+ At least one of them; X is selected from halogen anions, O 2- and S 2- At least one of the following; the halide anion includes F - Cl - ,Br - and I - ; More preferably, the material having the ABX3 structure is selected from CH3NH3PbI3, HN=CHNH3PbI3, Cs x ((HN=CHNH3) y (CH3NH3) 1-y ) 1-x Pb(I z Br 1-z 3. Cs x ((HN=CHNH3) y (CH3NH3) 1-y ) 1-x Pb(I z Cl 1-z At least one of the following three conditions must be met: x, y, and z satisfy: 0 < x ≤ 0.25, 0.5, ... <y≤1、0.75≤z<1; More preferably, the thickness of the perovskite layer is 900nm-1500nm.

7. The perovskite solar cell according to claim 6, characterized in that, A perovskite passivation layer, an electron transport layer, and a metal electrode are sequentially disposed on the perovskite layer. Preferably, the perovskite passivation layer contains at least one of hydroxyl, carboxyl, amide, amino, and aldehyde groups; preferably, the thickness of the perovskite passivation layer is 1 nm-20 nm. Preferably, the electron transport layer contains at least one of fullerene or its derivative, copper bath, tin oxide, and titanium oxide; preferably, the thickness of the electron transport layer is 1 nm-50 nm. Preferably, the metal electrode is selected from at least one of silver electrode, gold electrode, copper electrode, aluminum electrode, carbon electrode, silicon carbide electrode and transparent conductive oxide electrode; preferably, the thickness of the metal electrode is 10nm-350nm.

8. A method for preparing a perovskite solar cell according to any one of claims 5-7, characterized in that, include: The hole transport layer and the transport layer passivation layer are sequentially formed on the substrate.

9. The preparation method according to claim 8, characterized in that, The preparation process of the passivation layer of the transport layer includes: mixing the self-assembled molecular material, the hydrophilic functional material and the solvent to obtain a passivation layer solution, coating the passivation layer solution onto the hole transport layer and annealing it; Preferably, the concentration of the passivation layer solution is 0.1 mg / mL to 5.0 mg / mL; Preferably, the solvent is selected from at least one of dimethyl sulfoxide, N,N-dimethylformamide, isopropanol, water, and ethanol; Preferably, the method further includes forming a perovskite layer, a perovskite passivation layer, an electron transport layer, and a metal electrode sequentially on the transport layer passivation layer.

10. A photovoltaic module, characterized in that, This includes the perovskite solar cell according to any one of claims 5-7 or the perovskite solar cell prepared by the preparation method according to any one of claims 8-9.

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