Perovskite solar cell and preparation method thereof, photovoltaic module, power generation device and power utilization device

Abstract

The invention relates to a perovskite solar cell and a preparation method thereof, a photovoltaic module, a power generation device and a power utilization device, the perovskite solar cell comprises a first electrode, a hole injection layer, a hole transport layer, a perovskite light absorption layer and a second electrode which are stacked in sequence, the hole injection layer comprises a compound with a molecular formula of AxBy, a comprises one or more of chromium, molybdenum and tungsten, B comprises one or more of oxygen, sulfur, selenium and tellurium, 1 < = x < = 2, and 2 < = y < = 3. The photoelectric conversion efficiency of the perovskite solar cell can be improved.

Description

Technical Field

[0001] This application relates to the field of solar cells, and more particularly to a perovskite solar cell and its preparation method, photovoltaic module, power generation device and power consumption device. Background Technology

[0002] Perovskite solar cells are solar cells that use organometal halide perovskite materials as light-absorbing layers. They have excellent photoelectric properties and simple fabrication methods, bringing new possibilities and hope to photovoltaic power generation.

[0003] Currently, how to further improve the photoelectric conversion efficiency of perovskite solar cells is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a perovskite solar cell and its preparation method, photovoltaic module, power generation device and power consumption device. The photoelectric conversion efficiency of the perovskite solar cell in this application can be further improved.

[0005] In a first aspect, this application proposes a perovskite solar cell, which includes a first electrode, a hole injection layer, a hole transport layer, a perovskite light-absorbing layer, and a second electrode stacked sequentially. The hole injection layer comprises a material with the molecular formula A... x B y The compound, A includes one or more elements selected from chromium, molybdenum and tungsten, B includes one or more elements selected from oxygen, sulfur, selenium and tellurium, 1≤x≤2, 2≤y≤3.

[0006] Therefore, in the embodiments of this application, the hole injection layer includes a molecular formula of A x B y The compound has a better energy level match between the hole transport layer and the hole injection layer, and a better energy level match between the hole injection layer and the first electrode. It can increase hole injection at the interface between the hole injection layer and the hole transport layer, thereby enhancing hole migration ability and improving the photoelectric conversion efficiency of perovskite solar cells.

[0007] In some embodiments, the work function Φ1 of the hole injection layer toward the surface of the hole transport layer, in eV; and the work function Φ2 of the hole injection layer toward the surface of the first electrode, in eV, wherein...

[0008] From 1% to 10%, optionally, It ranges from 2% to 4%.

[0009] Therefore, when the hole injection layer in the embodiment of this application meets the above conditions, the hole injection layer has good energy level matching with the hole transport layer and the first electrode, which is beneficial to enhancing the hole migration or transport capability and improving the photoelectric conversion efficiency of the perovskite solar cell.

[0010] In some embodiments, the work function of the surface of the hole injection layer facing the hole transport layer is 4.5 eV to 5.15 eV, optionally 4.7 eV to 5.10 eV. The relatively high work function of the surface of the hole injection layer facing the hole transport layer allows for a better energy level match between the hole injection layer and the hole transport layer, which is more conducive to improving hole transport capability.

[0011] In some embodiments, the surface of the hole injection layer facing the hole transport layer includes element A, and the percentage of high-valence A atoms in the total number of A atoms is a first atomic percentage; the surface of the hole injection layer facing the first electrode includes element A, and the percentage of high-valence A atoms in the total number of A atoms is a second atomic percentage, wherein the first atomic percentage is greater than the second atomic percentage, and a high valence state refers to a valence state greater than or equal to +3.

[0012] Therefore, the surface of the hole injection layer facing the hole transport layer has a relatively high proportion of high-valence A elements, and more anion vacancies are filled. Conversely, the surface of the hole injection layer facing the first electrode has a relatively low proportion of high-valence A elements, and more anion vacancies. The reduced vacancy defects on the surface of the hole injection layer facing the hole transport layer and the contact surface of the hole transport layer decrease the likelihood of carriers being captured at the interface. The difference between the surface of the hole injection layer facing the hole transport layer and the surface of the hole injection layer facing the first electrode further enhances the matching ability of the work function. It also makes it easier to guide holes to migrate from the surface of the hole injection layer facing the hole transport layer to the surface of the hole injection layer facing the first electrode, thus improving migration efficiency.

[0013] In some embodiments, element A includes chromium, with a high valence state of +3 or higher. In some embodiments, element A includes molybdenum, with a high valence state of +4 or higher. In some embodiments, element A includes tungsten, with a high valence state of +4 or higher.

[0014] In some embodiments, the thickness of the hole injection layer is between 1 nm and 5 nm. When the thickness of the hole injection layer is within this range, the migration ability of holes can be effectively improved, thereby enhancing the photoelectric conversion performance of the perovskite solar cell.

[0015] In some embodiments, the compound includes one or more of molybdenum telluride, molybdenum oxide, molybdenum sulfide, and molybdenum selenide. These materials are more energy-matched with the hole transport layer and with the energy level of the first electrode, which is beneficial for improving hole migration capability and enhancing the photoelectric conversion efficiency of the perovskite solar cell.

[0016] In some embodiments, the first electrode is a transparent electrode. This configuration allows light to enter, resulting in a trans-perovskite cell.

[0017] In some embodiments, the transparent electrode comprises a transparent conductive oxide. Since the energy level difference between the transparent electrode and the hole transport layer is large, a hole injection layer is provided between the transparent electrode and the hole transport layer to reduce the energy level difference between adjacent layers, enhance hole migration capability, and improve the photoelectric conversion efficiency of perovskite solar cells.

[0018] In some embodiments, the transparent conductive oxide includes one or more of indium tin oxide, fluorine-doped tin oxide, indium-doped zinc oxide, aluminum-doped zinc oxide, boron-doped zinc oxide, antimony-doped tin oxide, and indium-doped tungsten oxide.

[0019] In some embodiments, the hole transport layer comprises an organic compound, including one or more of the following: poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, poly-3-hexylthiophene, methoxytriphenylamine-fluoroformamidinium, triphenylamine with a triphenylene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-4-anilinecarbazole-spirobifluorene, polythiophene, and self-assembled monomolecule materials.

[0020] Therefore, the hole transport layer can effectively transport holes, reduce carrier recombination at the interface between the photoelectric conversion layer and the hole transport layer, and improve the photoelectric conversion efficiency of perovskite solar cells.

[0021] In some embodiments, the hole transport layer comprises an inorganic compound, which includes one or more of a metal oxide, cuprous iodide, and cuprous thiocyanate.

[0022] Therefore, the hole transport layer can effectively transport holes, reduce carrier recombination at the interface between the photoelectric conversion layer and the hole transport layer, and improve the photoelectric conversion efficiency of perovskite solar cells.

[0023] In some embodiments, the metal oxide includes one or more of nickel oxide, molybdenum oxide, and cuprous oxide.

[0024] In some embodiments, the perovskite solar cell further includes an electron transport layer disposed between the perovskite light-absorbing layer and the second electrode. This electron transport layer effectively transports electrons, reduces carrier recombination at the interface between the photoelectric conversion layer and the electron transport layer, and improves the photoelectric conversion efficiency of the perovskite solar cell.

[0025] Secondly, this application proposes a method for fabricating a perovskite solar cell. The method includes: providing a first electrode; providing a hole injection source to the first electrode; and processing the hole injection source to form a hole injection layer, wherein the processing includes annealing, and the hole injection layer comprises materials with the molecular formula A. x B y The compound A includes one or more elements selected from chromium, molybdenum and tungsten, and B includes one or more elements selected from oxygen, sulfur, selenium and tellurium, where 1≤x≤2 and 2≤y≤3; a hole transport layer, a perovskite light-absorbing layer and a second electrode are sequentially disposed on the hole injection layer to form a perovskite solar cell.

[0026] Therefore, in this embodiment, a hole injection source is provided on the first electrode, and the hole injection source is annealed to make the energy levels of the hole injection layer and the hole transport layer formed by the hole injection source more matched, and the energy levels of the hole injection layer and the first electrode more matched, thereby effectively improving the hole migration capability and improving the photoelectric conversion efficiency of the perovskite solar cell.

[0027] In some embodiments, the annealing temperature for the annealing process is between 150°C and 250°C. Annealing under these conditions results in a higher work function of the hole injection layer, enhanced hole migration capability, and the ability to modulate the energy levels of the hole injection layer, leading to better energy level matching between adjacent layers and thus improving the photoelectric conversion efficiency of perovskite solar cells.

[0028] In some embodiments, the annealing time for the annealing process is 10 to 20 minutes. Annealing under the above conditions can result in a higher work function of the hole injection layer, enhanced hole migration ability, and the ability to modulate the energy levels of the hole injection layer, making the energy levels between adjacent layers more matched, which is beneficial to improving the photoelectric conversion efficiency of perovskite solar cells.

[0029] In some embodiments, the processing also includes plasma treatment, a step of treating the hole injection source to form a hole injection layer, including: sequentially annealing the hole injection source and plasma treatment to form a hole injection layer.

[0030] Therefore, in the embodiments of this application, after annealing and plasma treatment, the hole injection source can further enhance the migration ability of holes in the hole injection layer, which is beneficial to improving the photoelectric conversion efficiency of perovskite solar cells.

[0031] In some embodiments, the plasma treatment atmosphere includes one or both of oxygen and ozone. Oxygen or ozone plasma treatment fills oxygen vacancies on the surface of the hole injection layer, resulting in a relatively higher valence state of element A on the surface of the hole injection layer, which is more conducive to hole migration.

[0032] In some embodiments, the atmosphere for plasma treatment also includes an inert gas, including one or more of argon and helium. This allows for effective control of the concentration of oxygen and / or ozone, and thus, effective control of the plasma treatment rate.

[0033] In some embodiments, the plasma treatment time is 3 to 15 minutes. Treatment under the above plasma treatment conditions can further improve the surface properties of the hole injection layer and enhance the migration ability of holes.

[0034] Thirdly, this application proposes a photovoltaic module, which includes one or more perovskite solar cells as described in any embodiment of the first aspect of this application or perovskite solar cells prepared by any method described in any embodiment of the second aspect of this application.

[0035] Fourthly, this application proposes a power generation device, which includes a photovoltaic module according to any embodiment of the third aspect of this application.

[0036] Fifthly, this application proposes an electrical device, which includes a photovoltaic module according to any embodiment of the third aspect of this application. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell provided in some embodiments of this application;

[0039] Figure 2 These are schematic diagrams of the structure of perovskite solar cells provided in other embodiments of this application;

[0040] Figure 3 This is a schematic diagram of the structure of a perovskite solar cell provided in some embodiments of this application;

[0041] Figure 4 These are schematic diagrams of the structure of photovoltaic modules provided in some embodiments of this application;

[0042] Figure 5This is a schematic diagram of the structure of an electrical device provided in some embodiments of this application.

[0043] The accompanying drawings are not necessarily drawn to scale.

[0044] The following are the labeling elements in the figure:

[0045] X, thickness direction;

[0046] 10. Perovskite solar cells;

[0047] 11. First electrode;

[0048] 12. Hole injection layer; 121. First surface; 122. Second surface;

[0049] 13. Hole transport layer;

[0050] 14. Perovskite light-absorbing layer;

[0051] 15. Electron transport layer;

[0052] 16. Second electrode;

[0053] 1. Photovoltaic modules;

[0054] 2. Electrical appliances. Detailed Implementation

[0055] The following detailed description, with appropriate reference to the accompanying drawings, specifically discloses embodiments of the perovskite solar cell, photovoltaic module, power generation device, and power consumption device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0056] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, it is also expected that ranges of 60 to 110 and 80 to 120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise stated, the numerical range "a to b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 and 5" have been listed in this article; "0 to 5" is just a shortened representation of these numerical combinations. In addition, when a parameter is stated as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0057] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0058] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0059] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, if a method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if it is mentioned that the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0060] In this application, "multiple" means two or more (including two).

[0061] Perovskite solar cells convert solar energy into electrical energy. Their operation mainly includes: exciton generation and separation, free carrier transport, carrier collection, and current generation. Specifically, in a perovskite solar cell, sunlight is absorbed by the perovskite light-absorbing layer, which absorbs photons and generates excitons. Due to the low Coulomb force binding of the perovskite layer, the excitons subsequently separate into free electrons and holes. These separated free carriers transport within the perovskite layer, and the electrons and holes are collected by electrodes. When connected to an external load, they form a current.

[0062] To improve the efficiency of carrier extraction and transport, a transport layer can be set between the electrode and the perovskite light-absorbing layer. The transport layer includes a hole transport layer, which can transport holes. However, studies have found that the hole transport layer still has insufficient hole transport capability, resulting in poor photoelectric conversion efficiency of perovskite solar cells.

[0063] In view of this, the embodiments of this application also provide a hole injection layer, which can increase the hole migration capability, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0064] Perovskite solar cells

[0065] In a first aspect, this application proposes a perovskite solar cell.

[0066] like Figure 1 As shown, the perovskite solar cell 10 includes a first electrode 11, a hole injection layer 12, a hole transport layer 13, a perovskite light-absorbing layer 14, and a second electrode 16, which are sequentially stacked. The hole injection layer 12 comprises materials with the molecular formula A... x B y The compound, A includes one or more elements selected from chromium, molybdenum and tungsten, B includes one or more elements selected from oxygen, sulfur, selenium and tellurium, 1≤x≤2, 2≤y≤3.

[0067] Hole injection layer 12 includes molecules with the molecular formula A x B y The compound improves the energy level matching between the hole transport layer 13 and the hole injection layer 12, and also improves the energy level matching between the hole injection layer 12 and the first electrode 11. This increases hole injection at the interface between the hole injection layer 12 and the hole transport layer 13, thereby enhancing hole migration capability and improving the photoelectric conversion efficiency of the perovskite solar cell 10. Here, x can be 1, 1.5, 2, or any two of the above values, and y can be 2, 2.5, 3, or any two of the above values.

[0068] The hole injection layer 12 includes two surfaces that are opposite each other along the thickness direction X of the perovskite solar cell 10. One surface is disposed facing the hole transport layer 13 and is defined as the first surface 121; the other surface is disposed facing the first electrode 11 and is defined as the second surface 122.

[0069] In some embodiments, the work function Φ1 of the surface of the hole injection layer 12 facing the hole transport layer 13, i.e., the first surface 121, is in eV; the work function Φ2 of the surface of the hole injection layer 12 facing the first electrode 11, i.e., the second surface 122, is in eV.

[0070] For example, 1% to 10%, The percentage can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any two of the above values, and can be selected from 2% to 4%.

[0071] When the hole injection layer 12 meets the above conditions, it enables good energy level matching between the hole injection layer 12, the hole transport layer 13, and the first electrode 11, which is beneficial to enhance hole migration or transport capabilities and improve the photoelectric conversion efficiency of the perovskite solar cell 10.

[0072] For example, the work function of the first surface 121 is 4.5 eV to 5.15 eV, such as 4.5 eV, 4.6 eV, 4.7 eV, 4.75 eV, 4.8 eV, 4.85 eV, 4.9 eV, 4.95 eV, 5.0 eV, 5.05 eV, 5.10 eV, 5.15 eV, or any combination of the above values, and can be selected as 4.7 eV to 5.10 eV. Setting the work function of the first surface 121 in this way facilitates its matching with the hole transport layer and further enhances the hole transport capability.

[0073] In this embodiment, the work function of the surface of the hole injection layer 12 has a meaning known in the art. The work function refers to the minimum energy required to release an electron from the surface of a material into a vacuum. It can be detected using equipment and methods known in the art, such as ultraviolet photoelectron spectroscopy (UPS) or X-ray photoelectron spectroscopy (XPS). For example, the measurement steps using ultraviolet photoelectron spectroscopy UPS are as follows:

[0074] A 0.5cm x 0.5cm sample was placed under vacuum and tested using a Shimadzu Axis Supra+ testing system. The testing requirements were: 0.5 nm etching (calculated based on a Ta₂O₅ etching rate of 4 nm / min), a -3.5V bias voltage applied to the sample, and the sample subjected to Ar... + Ion sputtering cleaning, Ar+ The ion energy is 2 keV, and the beam current density is 0.5 μA / mm. 2 ;

[0075] Calculation formula:

[0076] W = 21.22 eV – E cutoff ;

[0077] VBM = –W –E onset ;

[0078] CBM = VBM + E g ;

[0079] Where W represents the sample work function, E cutoff It is the secondary electron cutoff edge, E onset It is the secondary electron initiation edge, VBM is the sample valence band top, CBM is the sample conductivity bottom, E g It is the sample band gap.

[0080] In the embodiments of this application, the molecular formula is A x B y The compound may include one or more of chromium oxide, molybdenum oxide, tungsten oxide, chromium sulfide, molybdenum sulfide, tungsten sulfide, chromium selenide, molybdenum selenide, tungsten selenide, chromium telluride, molybdenum telluride, and tungsten telluride; optionally, the compound may include one or more of molybdenum telluride, molybdenum oxide, molybdenum sulfide, and molybdenum selenide.

[0081] The aforementioned material is more compatible with the energy levels of the hole transport layer 13 and the first electrode 11, which is beneficial for improving hole migration capability and enhancing the photoelectric conversion efficiency of the perovskite solar cell 10.

[0082] The anions and cations of the compound are distributed in the hole injection layer 12, which can be distributed on the surface or inside the hole injection layer 12; the first surface 121 includes element A, which exists in the form of cations. The cations have multiple valence states, and the percentage of the number of atoms of element A in the high valence state is the first atomic percentage; the second surface 122 includes element A, which exists in the form of cations. The cations have multiple valence states, and the percentage of the number of atoms of element A in the high valence state is the second atomic percentage; the first atomic percentage is greater than the second atomic percentage, and the high valence state refers to the valence state greater than or equal to +3.

[0083] For example, element A includes chromium, and the valence states of chromium include +2, +3, +6, etc. The highest valence state of chromium is a valence state greater than or equal to +3.

[0084] For example, element A includes molybdenum, and the valence states of molybdenum include +1, +2, +3, +4, +5, +6, etc. The highest valence state of molybdenum is a valence state greater than or equal to +4.

[0085] For example, element A includes tungsten, and the valence states of tungsten include +1, +2, +3, +4, +5, +6, etc. The highest valence state of tungsten is a valence state greater than or equal to +4.

[0086] The first surface 121 has a relatively high proportion of high-valence A elements, filling more anion vacancies. The second surface 122 has a relatively low proportion of high-valence A elements, resulting in more anion vacancies. The reduced vacancy defects at the interface between the first surface 121 and the hole transport layer 13 decrease the likelihood of hole carriers being captured at the interface, which is more conducive to hole injection and transport. The difference between the first surface 121 and the second surface 122 further enhances the matching ability of the work function and makes it easier to guide holes to migrate from the first surface 121 to the second surface 122, improving migration efficiency.

[0087] The valence state of element A can be tested using X-ray photoelectron spectroscopy (XPS). The valence state of the element is determined by analyzing the chemical shift. The collected data is then processed, and the content of element A corresponding to the valence state is determined based on the peak area.

[0088] In some embodiments, the thickness of the hole injection layer 12 is 1 nm to 5 nm, for example, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm or any combination of two of the above values.

[0089] When the thickness of the hole injection layer 12 is within the above range, it can effectively improve the migration ability of holes and improve the photoelectric conversion performance of the perovskite solar cell 10.

[0090] In some embodiments, one or both of the first electrode 11 and the second electrode 16 are transparent electrodes to allow light to enter.

[0091] In some embodiments, the electrode material in the first electrode 11 includes one or more of transparent conductive oxides, metals, and carbon materials. The transparent conductive oxides include one or more of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), antimony-doped tin oxide, and indium-doped tungsten oxide (IWO). The metals include, but are not limited to, one or more of silver, copper, gold, aluminum, and platinum. The carbon materials include one or more of graphite, graphene, and carbon nanotubes.

[0092] Optionally, the first electrode 11 is a transparent electrode, which is the electrode that first receives incident light. Optionally, the transparent electrode comprises a transparent conductive oxide, in which case the resulting perovskite solar cell is an inverted device. Since the energy level difference between the transparent electrode and the hole transport layer 13 is relatively large, a hole injection layer 12 is provided between the transparent electrode and the hole transport layer 13 to reduce the energy level difference between adjacent layers, enhance hole migration capability, and improve the photoelectric conversion efficiency of the perovskite solar cell 10.

[0093] In some embodiments, the thickness of the first electrode 11 is from 70 nm to 600 nm, for example, 70 nm, 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 280 nm, 300 nm, 320 nm, 350 nm, 380 nm, 400 nm, 420 nm, 450 nm, 480 nm, 500 nm, 520 nm, 550 nm, 580 nm, 600 nm, or any range of two of the above values.

[0094] When the thickness of the first electrode 11 is within the above range, the resistance of the device can be effectively reduced, the migration ability of holes can be improved, and the photoelectric conversion efficiency of the perovskite solar cell 10 can be improved.

[0095] In some embodiments, the electrode material of the second electrode 16 includes one or more of transparent conductive oxides, metals, and carbon materials. The transparent conductive oxides include one or more of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), antimony-doped tin oxide, and indium-doped tungsten oxide (IWO). The metals include, but are not limited to, one or more of silver, copper, gold, aluminum, and platinum. The carbon materials include one or more of graphite, graphene, and carbon nanotubes.

[0096] Hole transport layer 13, as a carrier transport layer, can effectively transport holes, reduce carrier recombination at the interface between the photoelectric conversion layer and hole transport layer 13, and improve the photoelectric conversion efficiency of perovskite solar cell 10.

[0097] Hole transport layer 13 includes hole transport material, which includes one or more of the following materials and their derivatives and materials obtained by doping or passivation: organic compounds and inorganic compounds.

[0098] Organic compounds include one or more of the following: poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, poly-3-hexylthiophene, methoxytriphenylamine-fluoroformamidinium, triphenylamine with a triphenylene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-4-anilinecarbazole-spirobifluorene, polythiophene, and self-assembled monomolecules; and / or

[0099] Hole transport layer 13 includes inorganic compounds, including one or more of metal oxides, cuprous iodide (CuI), and cuprous thiocyanate; wherein the metal oxide contains one or more of Ni, Mo, and Cu, such as nickel oxide (NiO). x One or more of molybdenum oxide (MoO3) and cuprous oxide (CuO).

[0100] In some embodiments, the material that self-assembles a monolayer satisfies the structure shown in the following general formula: QLA, wherein Q is selected from substituted or unsubstituted carbazole or triphenylamine groups, L is selected from substituted or unsubstituted alkylene chains, and A is selected from oxyacid groups.

[0101] In some embodiments, in the self-assembled monolayer material, the substituents of the substituted or unsubstituted carbazole or triphenylamine groups include any one of the following: halogen groups, alkoxy groups, oxyacid groups, substituted or unsubstituted aromatic groups with 6 to 15 cyclic atoms, substituted or unsubstituted heteroaromatic groups with 5 to 15 cyclic atoms, and substituted or unsubstituted alkyl groups with 1 to 5 carbon atoms. In this application, the structure of the substituted or unsubstituted carbazole or triphenylamine groups allows the organic compound to have energy levels more compatible with perovskite materials, further improving the performance of solar cells when used in the fabrication of hole transport layers.

[0102] In some embodiments, the substituted or unsubstituted alkylene chains in the self-assembled monolayer material include any one of the following: alkylene chains with 2 to 11 carbon atoms substituted or unsubstituted by halogen groups, alkoxy groups, oxyacid groups, aromatic groups with 6 to 15 cyclic atoms, or heteroaromatic groups with 5 to 15 cyclic atoms. By controlling the number of carbon atoms and substituents in L, the steric hindrance of the organic compound is reduced while its hydrophobicity is improved, further enhancing the photoelectric conversion efficiency and stability of the solar cell.

[0103] In some embodiments, in the self-assembled monolayer material, the oxyacid group is selected from any one of phosphonic acid groups, hypophosphite groups, sulfonic acid groups, carboxylic acid groups, sulfinic acid groups, boric acid groups, or silicate groups.

[0104] In some embodiments, the halogen group includes any one of F, Cl, Br, and I.

[0105] In some embodiments, the heteroatoms in the heteroaromatic group are selected from at least one of N, O, and S, so that the organic compound has an energy level that is more compatible with commonly used metal oxide hole transport materials and perovskite materials, thereby further improving the performance of solar cells when applied to the preparation of passivation films for solar cells.

[0106] In some embodiments, the alkoxy group is typically represented by RO-, such as methoxy CH3O-, ethoxy C2H5O-, propoxy C3H7O-, etc.

[0107] In some embodiments, the self-assembled monomolecules include [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-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), and [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphonic acid (Br- The self-assembled monomolecule material selected from at least one of the following: 4PACz, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), and [2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid (Br-2PACz). Using the above-mentioned materials for self-assembled monomolecule materials exhibits good hole transport efficiency and good energy level matching with the perovskite layer, which is beneficial for improving the photoelectric conversion efficiency of perovskite solar cells.

[0108] like Figure 2 As shown, in some embodiments, the perovskite solar cell 10 further includes an electron transport layer 15 disposed between the perovskite light-absorbing layer 14 and the second electrode 16.

[0109] As a carrier transport layer, the electron transport layer 15 can effectively transport electrons, reduce carrier recombination at the interface between the photoelectric conversion layer and the electron transport layer 15, and improve the photoelectric conversion efficiency of the perovskite solar cell 10.

[0110] The electron transport layer 15 may include an electron transport material, which may include one or more of doped or undoped tin oxide, doped or undoped titanium oxide, doped or undoped zinc oxide, and doped or undoped organic molecular materials. The doping element may include one or more of Mg, Zn, Ag, Li, Rb, Ta, and Nb, for example, by doping with chlorides of the above elements. Specifically, the electron transport material may include [6,6]-phenylC 61 Methyl butyrate (PC) 61 BM), [6,6]-phenyl C 71 Methyl butyrate PC 71 BM, Fullerene C 60 Fullerene C 70 One or more of the following: tin dioxide (SnO2), zinc oxide (ZnO), etc.

[0111] In some embodiments, the perovskite solar cell 10 may further include a barrier layer disposed between the electron transport layer 15 and the second electrode 16. The barrier layer can block hole transport and improve electron mobility. Exemplarily, the barrier layer may include one or more of BCP (2,9-dimethyl-4,7-diphenyl-1,4-phenanthroline), IWO, and SiO2.

[0112] The perovskite light-absorbing layer 14 includes a perovskite material. After the perovskite material absorbs photons, it generates electron-hole pairs, which are then thermally heated to form excitons. Charge separation then occurs, with photogenerated electrons transitioning to the LUMO level of the perovskite light-absorbing layer 14 and photogenerated holes transitioning to the HOMO level of the perovskite light-absorbing layer 14.

[0113] Perovskite materials refer to compounds with a perovskite structure. Perovskite materials include one or more compounds with the molecular formula ABX3 or M2CDN6, where A, B, M, C, and D are cations, and X and N are anions.

[0114] Taking ABX3 as an example, in an ideal cubic crystal structure, the B cation has 6-fold coordination and is surrounded by an anionic octahedron, while the A cation has 12-fold cubic octahedral coordination. The cubic unit cell of this compound consists of the A cation located at the cubic corner, the B cation located at the body center, and the X anion located at the face center.

[0115] In some implementations, A and M each independently include Li. + Na + K + 、Rb + Cs + One or more of the following: methylamine cation, ethylamine cation, propylamine cation, butylamine cation, pentamine cation, hexamine cation, formamidin cation, or imidazole cation.

[0116] In some implementations, B includes Ca 2+ 、Sr 2+ Cd 2+ Cu 2+ Ni 2+ Mn 2+ Fe 2+ Co 2+ Pd 2+ 、Ge 2+ Sn 2 + Pb 2+ Sn 2+ Yb 2+ and Eu 2+ One or more cations, etc.

[0117] In some implementations, X and N each independently include F. - Cl - ,Br - Or I - One or more of them.

[0118] In some implementations, C includes Cs + Ag + K + Or Ru + One or more of them.

[0119] In some implementations, D includes Bi. 3+ Ni 3+ Fe 3+ Sb 3+ In 3+ or Cu 3+ One or more of them.

[0120] For example, perovskite materials include CH8I3N2Pb (FAPbI3) and Cs. 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 3. One or more of CsPbBr3, CsPbI3, CsFAPbI3, and MAFAPbI3, wherein MA + The methylamine cation CH3NH3 + FA represents formamidinium cation ((NH2)2CH + ).

[0121] In some embodiments, the thickness of the perovskite light-absorbing layer 14 is between 200 nm and 1000 nm, for example, 200 nm, 250 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, or any combination of two of the above values. When the thickness of the perovskite light-absorbing layer 14 is within the above range, the photoelectric conversion function of the perovskite light-absorbing layer 14 can be effectively utilized, thereby improving the photoelectric conversion efficiency of the perovskite solar cell 10.

[0122] The X-site may contain vacancy defects, forming bulk defects; the X anion at the corresponding X-site may not be coordinated and may migrate, potentially leading to defects on the surface or grain boundaries of the perovskite crystal. In this embodiment, a passivation material can be further provided in the perovskite light-absorbing layer 14. The passivation material can effectively passivate defects in the perovskite material, improve the crystallinity and optical performance of the perovskite light-absorbing layer 14, thereby improving the photoelectric conversion efficiency of the perovskite solar cell 10. The passivation material can be any commonly used passivation material in the art.

[0123] The perovskite solar cell 10 can be a nip structure or a pin structure.

[0124] like Figure 2 As shown, the perovskite solar cell 10 includes a first electrode 11, a hole injection layer 12, a hole transport layer 13, a perovskite light-absorbing layer 14, an electron transport layer 15, and a second electrode 16, which are sequentially stacked along its thickness direction X. Optionally, functional layer structures such as a buffer layer and a passivation layer may be further included between the transport layer and the perovskite light-absorbing layer 14. Figure 2 The image shown is an inverted perovskite solar cell 10; Figure 2 The middle arrow indicates the direction of the incident light.

[0125] like Figure 3 As shown, the perovskite solar cell 10 includes a second electrode 16, an electron transport layer 15, a perovskite light-absorbing layer 14, a hole transport layer 13, a hole injection layer 12, and a first electrode 11, which are sequentially stacked along its thickness direction X. Optionally, functional layer structures such as a buffer layer and a passivation layer may be further included between the transport layer and the perovskite light-absorbing layer 14. Figure 3 The image shown is of the formal structure of a perovskite solar cell 10; Figure 3 The middle arrow indicates the direction of the incident light.

[0126] In the embodiments of this application, the thickness of each film layer in the perovskite solar cell 10 can be detected using equipment and methods known in the art, such as using an ellipsometer to detect the film thickness, and the test method can refer to the standard test.

[0127] The method for fabricating the perovskite solar cell 10 according to the embodiments of this application includes:

[0128] Step S100: Provide the first electrode;

[0129] Step S200: Provide the hole injection source to the first electrode 11;

[0130] Step S300: After processing the hole injection source, a hole injection layer 12 is formed. The processing includes annealing. The hole injection layer 12 comprises materials with the molecular formula A. x B y The compound, A includes one or more elements selected from chromium, molybdenum and tungsten, B includes one or more elements selected from oxygen, sulfur, selenium and tellurium, 1≤x≤2, 2≤y≤3;

[0131] In step S400, at least a hole transport layer 13, a perovskite light-absorbing layer 14, and a second electrode 16 are sequentially disposed on the hole injection layer 12 to form a perovskite solar cell 10.

[0132] In this embodiment, a hole injection source is provided on the first electrode 11, and the hole injection source is annealed to make the energy levels of the hole injection layer 12 and the hole transport layer 13 formed by the hole injection source more matched, and the energy levels of the hole injection layer 12 and the first electrode 11 more matched, thereby effectively improving the hole migration capability and improving the photoelectric conversion efficiency of the perovskite solar cell 10.

[0133] In step S200, the hole injection source is provided to the first electrode 11. The hole injection source can be provided to the first electrode 11 by means of evaporation, sputtering, spin coating, immersion or ion plating, etc., and sputtering is an option.

[0134] In some embodiments, in step S300, the annealing process can make the work function of the hole injection layer 12 higher, enhance the migration ability of holes, and regulate the energy level of the hole injection layer 12, so that the energy levels between adjacent layers are more matched, which is beneficial to improving the photoelectric conversion efficiency of the perovskite solar cell 10.

[0135] For example, the annealing temperature for the annealing process is 150°C to 250°C, such as 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, or any range of two of the above values.

[0136] For example, the annealing time for the annealing process is 10 min to 20 min, such as 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, or any range of two of the above values.

[0137] Optionally, the processing in step S200 may further include plasma processing; specifically, step S300 may include: annealing the hole injection source and then performing plasma processing in sequence to form a hole injection layer 12.

[0138] After annealing and plasma treatment, the hole injection source can further enhance the migration ability of holes in the hole injection layer 12, which is beneficial to improving the photoelectric conversion efficiency of the perovskite solar cell 10.

[0139] Exemplarily, the atmosphere for plasma treatment includes at least one of oxygen and ozone. Optionally, the atmosphere for plasma treatment also includes an inert gas; further optionally, the atmosphere for plasma treatment includes oxygen or ozone. Oxygen or ozone plasma treatment fills oxygen vacancies on the surface of the hole injection layer 12, resulting in a relatively higher valence state of element A on the surface of the hole injection layer 12, which is more conducive to hole migration.

[0140] Optionally, the volume percentage of the inert gas in the second gas is 30% to 70%, for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or any range of two of the above values.

[0141] Optionally, the total volume percentage of oxygen and ozone in the second gas is 30% to 70%, such as 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or any range of two of the above values.

[0142] For example, the plasma treatment time is 3 min to 15 min, such as 3 min, 5 min, 6 min, 8 min, 10 min, 12 min, 15 min, or any range of two of the above values.

[0143] photovoltaic modules

[0144] Secondly, this application also provides a photovoltaic module.

[0145] like Figure 4 As shown, the photovoltaic module 1 includes a perovskite solar cell 10 according to any embodiment of the first aspect of this application.

[0146] In some embodiments, the photovoltaic module 1 may include at least one perovskite solar cell 10. For example, the photovoltaic module 1 may include one perovskite solar cell 10, or it may include multiple perovskite solar cells 10. When the photovoltaic module 1 includes multiple perovskite solar cells 10, the multiple perovskite solar cells 10 can be connected in series, parallel, or mixed configurations. A mixed configuration means that the multiple perovskite solar cells 10 are divided into multiple groups of cells, each group is internally connected in series, and then adjacent groups are connected in parallel; or each group is internally connected in parallel, and then adjacent groups are connected in series. Figure 4 As shown, the photovoltaic module 1 includes at least one perovskite solar cell 10.

[0147] In some embodiments, the photovoltaic module 1 includes a single-junction perovskite cell made of the perovskite cell described above, or a tandem cell including the perovskite cell described above.

[0148] The aforementioned tandem solar cell, by connecting a wide-bandgap cell and a narrow-bandgap cell in series, can more rationally utilize photons across the entire spectrum and reduce energy loss. Specifically, the tandem solar cell includes a bottom cell and a top cell. The bottom cell has a relatively narrow bandgap and can be a silicon cell, or it can be a perovskite solar cell 10. The top cell has a relatively wide bandgap and can be a perovskite solar cell 10. Exemplarily, the tandem solar cell can include any one of a crystalline silicon perovskite tandem solar cell or a full perovskite solar cell 10. Exemplarily, the aforementioned crystalline silicon perovskite tandem solar cell can include a crystalline silicon bottom cell and a perovskite top cell arranged in sequence, wherein the aforementioned perovskite solar cell 10 can be used as the perovskite top cell in the crystalline silicon perovskite tandem solar cell. Exemplarily, the aforementioned full perovskite solar cell 10 can include a first perovskite cell and a second perovskite cell arranged in sequence, wherein both the first perovskite cell and the second perovskite cell can be the perovskite solar cell 10 of this application.

[0149] Power generation unit

[0150] Thirdly, the embodiments of this application also provide a power generation device, including a photovoltaic module 1 of any embodiment of the second aspect of this application. By using the photovoltaic module 1, the transparency of the power generation device can be guaranteed, and the power generation device can have a high photoelectric conversion efficiency, which can be applied to application scenarios that require both transparency and conductivity.

[0151] Electrical appliances

[0152] Fourthly, the embodiments of this application also provide an electrical device 2.

[0153] like Figure 5 As shown, the electrical device 2 includes a photovoltaic module 1 according to any embodiment of the second aspect of this application.

[0154] Photovoltaic module 1 can be used as a power source for electrical device 2, or it can be used as an energy storage unit for photovoltaic module 1. Electrical device 2 can be, but is not limited to, mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0155] Figure 5 This is a schematic diagram of an example electrical device 2. The electrical device 2 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. The electrical device 2 includes a photovoltaic module 1. As another example, the electrical device 2 could be a mobile phone, tablet computer, laptop computer, etc.

[0156] Example

[0157] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on weight, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0158] Example 1

[0159] Fabrication of perovskite solar cells

[0160] (1) First electrode

[0161] The 2.0cm×2.0cm FTO layer (FTO layer thickness of 500nm) was ultrasonically cleaned for 30 minutes each with acetone, isoacetone and deionized water, and finally dried with nitrogen gas for later use. It was then placed in an ultraviolet ozone generator for further cleaning and used as the first electrode.

[0162] (2) Preparation of the hole injection layer

[0163] MoTe2 was sputtered onto the surface of the first electrode, annealed, and then subjected to plasma treatment to prepare a hole injection layer with a thickness of 2 nm.

[0164] (3) Nickel oxide (NiO) x Preparation of hole transport layer

[0165] NiO x A 25nm hole transport layer is prepared by sputtering onto the surface of the hole injection layer.

[0166] (4) Preparation of perovskite light-absorbing layer

[0167] A 1.5 mol / L CsFAMA (Cs) solution was spin-coated onto the surface of the hole transport layer at a speed of 4000 rpm. 0.1 FA 0.9 The precursor liquid of PbI3 was prepared by using DMF (N,N-dimethylformamide) and NMP (N-methylpyrrolidone) in a solvent ratio of 9:1. The mixture was then transferred to a constant temperature hot stage and heated at 100°C for 30 min. After cooling to room temperature, a perovskite light-absorbing layer with a thickness of 450 nm was formed.

[0168] (5) Fabrication of electron transport layer

[0169] A 10 mg / mL C60 isopropanol IPA solution was spin-coated onto the perovskite light-absorbing layer at 3000 rpm. The layer was then transferred to a constant temperature hot plate and heated at 100 °C for 10 min. After cooling to room temperature, a 20 nm electron transport layer was obtained.

[0170] (6) Preparation of IWO barrier layer

[0171] An IWO blocking layer was prepared on the surface of an electron transport layer using an electron beam deposition method.

[0172] (7) Preparation of the second electrode

[0173] The aforementioned devices were transferred to a vacuum coating machine to... A 70nm copper electrode was evaporated at a high speed to serve as the second electrode, thus completing the fabrication of the perovskite solar cell.

[0174] Comparative Example 1: Perovskite solar cells were prepared using a method similar to that of Example 1, except that nickel oxide (NiO) was directly prepared on the first electrode. x Hole transport layer, no hole injection layer is set.

[0175] Comparative Example 2: Perovskite solar cells were prepared using a method similar to that of Example 1, except that the compounds were modified.

[0176] Examples 2 to 8: Perovskite solar cells were prepared using a method similar to that of Example 1, except that the compounds were adjusted.

[0177] Examples 9 to 13: Perovskite solar cells were prepared using a method similar to that of Example 1. The difference from Example 1 was that the preparation process of the hole injection layer was adjusted. The specific parameters are shown in Table 1.

[0178] Example 14: Perovskite solar cells were fabricated using a method similar to that of Example 1, except that the thickness of the hole injection layer was adjusted to 5 nm.

[0179] Performance testing

[0180] The perovskite solar cells prepared in the above embodiments and comparative examples were placed in an atmospheric environment. An AM1.5G standard light source was used as the simulated sunlight source. A four-channel digital source meter (Keithley 2440) was used to measure the current-voltage characteristic curves of the perovskite solar cells under illumination. The open-circuit voltage Voc, short-circuit current density Jsc, and fill factor FF were obtained. The photoelectric conversion efficiency Eff was then calculated. The photoelectric conversion efficiency is calculated as follows: Eff = Pout / Pin × 100%, where Pout and Pin are the operating output power and incident light power of the perovskite solar cell, respectively, with the incident light power being 100 mW / cm². 2 .

[0181] Test Results

[0182] Table 1

[0183]

[0184] In Table 1, the plasma treatment time for Comparative Example 2 and each embodiment is 5 min.

[0185] In Example 12, the volume ratio of Ar to O2 was 50%:50%.

[0186] In Comparative Example 1, no compound was used, resulting in poor energy level matching between the hole transport layer and the first electrode, leading to poor photoelectric conversion efficiency of the perovskite solar cell.

[0187] Although Al2O3 was used as a compound in Comparative Example 2, this material could not effectively improve the energy level matching between the hole transport layer and the first electrode, resulting in poor photoelectric conversion efficiency of the perovskite solar cell.

[0188] The embodiments of this application are configured with A. x B y The compound, A, includes one or more elements selected from chromium, molybdenum, and tungsten, and B includes one or more elements selected from oxygen, sulfur, selenium, and tellurium. This material makes the energy levels between the hole transport layer and the hole injection layer more matched, and the energy levels between the hole injection layer and the first electrode more matched. It can increase hole injection at the interface between the hole injection layer and the hole transport layer, thereby enhancing hole migration ability and improving the photoelectric conversion efficiency of perovskite solar cells.

[0189] Examples 1 to 8 tested different compounds to meet the requirements of A. x B y All of the compounds can effectively improve the photoelectric conversion efficiency of perovskite solar cells; MoTe2 has a more outstanding effect on improving the photoelectric conversion efficiency.

[0190] Compared to Example 9, which does not perform plasma treatment, Example 1 performs annealing and plasma treatment, which can more effectively improve the photoelectric conversion efficiency of perovskite solar cells; in other words, the combined treatment of plasma and annealing is beneficial to improving photoelectric conversion efficiency.

[0191] The embodiments of this application demonstrate that by conducting experiments with different annealing temperatures, such as 150°C to 250°C, different annealing times, such as 10 min to 20 min, or different plasma atmospheres, such as oxygen, ozone, and inert gases, the photoelectric conversion efficiency can be improved.

[0192] Although illustrative embodiments have been demonstrated and described, those skilled in the art should understand that the above embodiments should not be construed as limiting the implementation of the present application, and that changes, substitutions and modifications can be made to the embodiments without departing from the spirit, principles and scope of the implementation of the present application.

Claims

1. A perovskite solar cell, characterized by, The perovskite solar cell comprises a first electrode, a hole injection layer, a hole transport layer, a perovskite light-absorbing layer and a second electrode which are sequentially stacked. The hole injection layer includes a compound of formula A x B y A includes one or more elements of chromium, molybdenum, and tungsten, B includes one or more elements of oxygen, sulfur, selenium, and tellurium, 1≤x≤2, 2≤y≤3.

2. The perovskite solar cell according to claim 1, wherein a work function of a surface of the hole injection layer facing the hole transport layer is Φ1, in eV; a work function of a surface of the hole injection layer facing the first electrode is Φ2, in eV, wherein, is from 1% to 10%.

3. The perovskite solar cell according to claim 2, characterized in that, is from 2% to 4%.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, the work function of the surface of the hole injection layer facing the hole transport layer is Φ1, in eV.

5. The perovskite solar cell according to claim 4, characterized in that, the work function of the surface of the hole injection layer facing the hole transport layer is Φ1, in eV.

6. The perovskite solar cell according to any one of claims 1 to 5, wherein a surface of the hole injection layer facing the hole transport layer comprises an A element, and a percentage of a number of atoms of the A element in a high valence state to a total number of atoms of the A element is a first atomic percentage; a surface of the hole injection layer facing the first electrode comprises an A element, and a percentage of a number of atoms of the A element in a high valence state to a total number of atoms of the A element is a second atomic percentage, wherein the first atomic percentage is greater than the second atomic percentage, and the high valence state refers to a valence state of greater than or equal to +3.

7. The perovskite solar cell according to claim 6, wherein the A element comprises a chromium element in a high valence state of greater than or equal to +3; and / or the A element comprises a molybdenum element in a high valence state of greater than or equal to +4; and / or the A element comprises a tungsten element in a high valence state of greater than or equal to +4.

8. The perovskite solar cell according to any one of claims 1 to 7, characterized in that, a thickness of the hole injection layer is 1 nm to 5 nm.

9. The perovskite solar cell according to any one of claims 1 to 8, characterized in that, the compound comprises one or more of molybdenum telluride, molybdenum oxide, molybdenum sulfide and molybdenum selenide.

10. The perovskite solar cell according to any one of claims 1 to 9, characterized in that, the first electrode is a transparent electrode.

11. The perovskite solar cell according to claim 10, characterized in that, the transparent electrode comprises a transparent conductive oxide.

12. The perovskite solar cell according to claim 11, characterized in that, the transparent conductive oxide comprises one or more of indium tin oxide, fluorine-doped tin oxide, indium-doped zinc oxide, aluminum-doped zinc oxide, boron-doped zinc oxide, antimony-doped tin oxide, and indium-doped tungsten oxide.

13. The perovskite solar cell according to any one of claims 1 to 12, characterized in that, the hole transport layer comprises an organic compound, and the organic compound comprises one or more of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, poly-3-hexylthiophene, methoxytriphenylamine-fluoromethylformamidine, triptycene-core triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-4-anilino carbazole-spirofluorene, polythiophene, and self-assembled monomolecular material; and / or the hole transport layer comprises an inorganic compound, and the inorganic compound comprises one or more of a metal oxide, cuprous iodide and cuprous thiocyanate.

14. The perovskite solar cell of claim 13, wherein, the metal oxide comprises one or more of nickel oxide, molybdenum oxide and cuprous oxide.

15. The perovskite solar cell according to any one of claims 1 to 14, characterized in that, the perovskite solar cell further comprises an electron transport layer disposed between the perovskite light-absorbing layer and the second electrode.

16. A method of manufacturing a perovskite solar cell, characterized by, The method comprises: providing a first electrode; providing a hole injection source to the first electrode; After the hole injection source is processed, a hole injection layer is formed, wherein the processing includes annealing treatment, and the hole injection layer includes a compound with a molecular formula of A x B y , A includes one or more elements of chromium, molybdenum and tungsten, B includes one or more elements of oxygen, sulfur, selenium and tellurium, 1≤x≤2, 2≤y≤3. sequentially disposing a hole transport layer, a perovskite light-absorbing layer and a second electrode on the hole injection layer to form a perovskite solar cell.

17. The method of making according to claim 16, wherein, The annealing temperature of the annealing process is 150-250°C; and / or The annealing time of the annealing process is 10-20 minutes.

18. The method of manufacturing according to claim 16 or 17, wherein, The method further comprises a plasma treatment, and the step of treating the hole injection source to form a hole injection layer comprises: treating the hole injection source sequentially by annealing and plasma treatment to form a hole injection layer.

19. The method of making according to claim 18, wherein, The atmosphere of the plasma treatment comprises one or both of oxygen and ozone; and / or The treatment time of the plasma treatment is 3-15 minutes.

20. The method of making according to claim 19, wherein, The atmosphere further comprises an inert gas, and the inert gas comprises one or more of argon and helium.

21. A photovoltaic module comprising one or more perovskite solar cells according to any one of claims 1 to 15 or prepared according to the method of any one of claims 16 to 20.

22. A power generation device comprising the photovoltaic module of claim 21.

23. An electrical utilization device comprising the photovoltaic module of claim 21.

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