Perovskite solar cell and electric device

Abstract

The invention provides a perovskite solar cell and an electric device. The perovskite solar cell comprises a perovskite layer, a buffer layer and a charge extraction layer which are stacked in sequence. The buffer layer contains an N-type semiconductor material or a P-type semiconductor material or a passivation material. The corresponding buffer layer is arranged between the perovskite layer and the charge extraction layer, so that the surface defects of the perovskite layer can be reduced, and the perovskite solar cell can maintain relatively high photoelectric conversion efficiency. And meanwhile, the buffer layer can play a certain role in protecting the surface of the perovskite layer and reduce the influence of the external environment on the perovskite layer, so that the stability of the photoelectric conversion efficiency of the perovskite solar cell can be improved.

Description

Technical Field

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

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Perovskite solar cells have good application prospects, but the stability of the photoelectric conversion efficiency of traditional perovskite solar cells needs to be further improved. Summary of the invention

[0004] In order to achieve the above-mentioned purpose, the present application provides a perovskite solar cell, comprising a perovskite layer, a buffer layer and a charge extraction layer stacked in sequence; the buffer layer contains an N-type semiconductor material or a P-type semiconductor material; and / or the buffer layer contains a passivation material.

[0005] The above-mentioned perovskite solar cell can reduce the surface defects of the perovskite layer by setting a corresponding buffer layer between the perovskite layer and the charge extraction layer, so that the perovskite solar cell maintains a high photoelectric conversion efficiency. At the same time, the buffer layer can play a certain protective role on the surface of the perovskite layer, reduce the impact of the external environment on the perovskite layer, and thus improve the stability of the photoelectric conversion efficiency of the perovskite solar cell.

[0006] In some embodiments, the buffer layer contains a passivation material, and the thickness of the buffer layer is 0.5 nm to 30 nm. When the thickness of the buffer layer is within this range, it can effectively promote the transmission of carriers while maintaining a good passivation effect, and further improve the stability of the photoelectric conversion efficiency of the perovskite solar cell.

[0007] In some embodiments, the passivation material includes at least one of silicon oxide and aluminum oxide. Silicon oxide and aluminum oxide can have a good field effect passivation effect on the perovskite layer, and can also reduce the damage to the perovskite layer during the subsequent preparation of the functional layer.

[0008] In some embodiments, the passivation material includes a quantum dot passivation material. The quantum dot passivation material has a relatively small particle size, which facilitates the preparation of the buffer layer in a variety of ways.

[0009] In some embodiments, the particle size of the passivation material is 3 nm to 8 nm. When the particle size of the passivation material is within this range, it is more convenient to prepare the corresponding buffer layer by solution method.

[0010] In some embodiments, the charge extraction layer includes an electron transport layer, and the buffer layer contains an N-type semiconductor material. By providing a buffer layer containing an N-type semiconductor material between the electron transport layer and the perovskite layer, the transmission of carriers between the perovskite layer and the electron transport layer can be promoted, which is conducive to further improving the stability of the photoelectric conversion efficiency of the perovskite solar cell.

[0011] In some embodiments, the N-type semiconductor material includes at least one of cadmium sulfide, cadmium selenide, cadmium telluride, zinc sulfide, zinc selenide and zinc telluride. These N-type semiconductor materials can further have a good passivation and energy level regulation effect on the surface of the perovskite layer, and improve the stability of the photoelectric conversion efficiency of the perovskite solar cell. At the same time, these N-type semiconductor materials are widely available and easy to obtain.

[0012] In some embodiments, the N-type semiconductor material includes a quantum dot N-type semiconductor material. The quantum dot N-type semiconductor material has a relatively small particle size, and is convenient for preparing the buffer layer in a variety of ways.

[0013] In some embodiments, the particle size of the N-type semiconductor material is 3 nm to 8 nm. When the particle size of the N-type semiconductor material is within this range, it is more convenient to prepare the corresponding buffer layer by a solution method.

[0014] In some embodiments, the surface of the N-type semiconductor material has a first modifying group, and the first modifying group includes a thiol group and / or an amino group. The first modifying group can cooperate with the N-type semiconductor material to passivate the surface defects of the perovskite layer, further improving the performance of the perovskite solar cell.

[0015] In some embodiments, the molar ratio of the first modifying group to the N-type semiconductor material is 1:(10-1000). The molar ratio of the first modifying group to the N-type semiconductor material within this range can better synergistically passivate the surface defects of the perovskite layer, which is beneficial to improving the performance of the perovskite solar cell.

[0016] In some embodiments, the thickness of the buffer layer is 5 nm to 20 nm. When the thickness of the buffer layer is within this range, the perovskite solar cell can maintain a relatively stable photoelectric conversion rate, and at the same time, the perovskite solar cell can maintain a relatively suitable thickness, which is conducive to promoting the use and promotion of perovskite solar cells.

[0017] In some embodiments, the electron transport layer contains a first metal oxide. The metal oxide has a low cost for preparing the electron transport layer, which is beneficial to reducing the manufacturing cost of the perovskite solar cell.

[0018] In some embodiments, the first metal oxide includes at least one of tin oxide, zinc oxide, titanium oxide and germanium oxide. Tin oxide, zinc oxide, titanium oxide and germanium oxide have good electron transport properties and are widely available and easy to obtain.

[0019] In some embodiments, the charge extraction layer includes a hole transport layer, and the buffer layer contains a P-type semiconductor material. By providing a buffer layer containing a P-type semiconductor material between the hole transport layer and the perovskite layer, the transmission of carriers between the perovskite layer and the hole transport layer can be promoted, which is conducive to further improving the stability of the photoelectric conversion rate of the perovskite solar cell.

[0020] In some embodiments, the P-type semiconductor material includes at least one of lead sulfide and lead selenide. These P-type semiconductor materials can further have a good passivation and energy level regulation effect on the surface of the perovskite layer, and improve the photoelectric conversion efficiency stability of the perovskite solar cell. At the same time, these N-type semiconductor materials are widely available and easy to obtain.

[0021] In some embodiments, the P-type semiconductor material includes a quantum dot P-type semiconductor material. The quantum dot P-type semiconductor material has a relatively small particle size, and is convenient for preparing the buffer layer in a variety of ways.

[0022] In some embodiments, the particle size of the P-type semiconductor material is 3 nm to 8 nm. When the particle size of the P-type semiconductor material is within this range, it is more convenient to prepare the corresponding buffer layer by a solution method.

[0023] In some embodiments, the surface of the P-type semiconductor material has a second modifying group, and the second modifying group includes a thiol group and / or an amino group. The second modifying group can cooperate with the P-type semiconductor material to passivate the surface defects of the perovskite layer, further improving the performance of the perovskite solar cell.

[0024] In some embodiments, the molar ratio of the second modifying group to the P-type semiconductor material is 1:(10-1000). The molar ratio of the second modifying group to the P-type semiconductor material within this range can better synergistically passivate the surface defects of the perovskite layer, which is beneficial to improving the performance of the perovskite solar cell.

[0025] In some embodiments, the hole transport layer contains a second metal oxide. The metal oxide has a low cost for preparing the hole transport layer, which is beneficial to reducing the manufacturing cost of the perovskite solar cell.

[0026] In some embodiments, the second metal oxide includes at least one of nickel oxide and molybdenum oxide. Nickel oxide and molybdenum oxide have good hole transport properties and are widely available and easy to obtain.

[0027] In some embodiments, the thickness of the buffer layer is 0.5 nm to 30 nm. When the thickness of the buffer layer is within this range, the perovskite solar cell can maintain a relatively stable photoelectric conversion rate, and at the same time, the perovskite solar cell can maintain a relatively suitable thickness, which is conducive to promoting the use and promotion of perovskite solar cells.

[0028] In some embodiments, the perovskite solar cell further comprises a transparent electrode layer and a metal electrode layer, wherein the transparent electrode layer is located on a side of the perovskite layer away from the buffer layer, and the metal electrode layer is located on a side of the charge extraction layer away from the buffer layer. By providing the transparent electrode layer and the metal electrode layer, a formal perovskite solar cell and an inverted perovskite solar cell can be obtained.

[0029] The present application also provides an electrical device, comprising the perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0031] Figure 1 Schematic diagram of the structure of a perovskite solar cell in one embodiment of the present application.

[0032] Figure 2 This is a schematic diagram of the structure of a perovskite solar cell in another embodiment of the present application.

[0033] Figure 3 It is a schematic diagram of an electrical device in one embodiment of the present application.

[0034] 100. Perovskite solar cell; 101. Base layer; 102. Transparent electrode layer; 103. Hole transport layer; 104. Perovskite layer; 105. Buffer layer; 106. Electron transport layer; 107. Metal electrode layer; 200. Perovskite solar cell; 201. Base layer; 202. Transparent electrode layer; 203. Hole transport layer; 204. Perovskite layer; 205. Buffer layer; 206. Electron transport layer; 207. Metal electrode layer; 300. Electrical device.

[0035] In order to better describe and illustrate the embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more drawings. The additional details or examples used to describe the drawings should not be considered to limit the scope of the disclosed inventions, the embodiments and / or examples currently described, and any of the best modes of these inventions currently understood. DETAILED DESCRIPTION

[0036] Some embodiments of the present application are disclosed in detail below with appropriate reference to the drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0037] The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0039] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0040] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0041] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0042] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which 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 may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0043] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0044] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true or exists, and B is false or does not exist; A is false or does not exist, and B is true or exists; or both A and B are true, or both A and B exist.

[0045] If not otherwise specified, in the present application, the term "room temperature" generally refers to 4°C to 30°C, preferably 25±5°C.

[0046] Unless otherwise stated, the terms used in this application have the well-known meanings commonly understood by those skilled in the art. Unless otherwise stated, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art. For example, the test can be performed according to the method provided in the examples of this application.

[0047] An embodiment of the present application provides a perovskite solar cell, comprising a perovskite layer, a buffer layer and a charge extraction layer stacked in sequence. The buffer layer contains an N-type semiconductor material or a P-type semiconductor material or a passivation material.

[0048] In this embodiment, in the perovskite solar cell, by providing a corresponding buffer layer between the perovskite layer and the charge extraction layer, the surface defects of the perovskite layer can be reduced, so that the perovskite solar cell maintains a high photoelectric conversion efficiency. At the same time, the buffer layer can play a certain protective role on the surface of the perovskite layer, reduce the impact of the external environment on the perovskite layer, and thus improve the stability of the photoelectric conversion efficiency of the perovskite solar cell.

[0049] It is understandable that the setting of the buffer layer can play a certain protective role on the surface of the perovskite layer, reduce the adverse effects of water, oxygen and other substances in the external environment on the perovskite layer, and thus improve the stability of the photoelectric conversion efficiency of perovskite solar cells.

[0050] Optionally, the N-type semiconductor material, the P-type semiconductor material, and the passivation material may be measured by a scanning electron microscope (SEM), an electron dispersive spectrometer (EDS), or an ultraviolet photoelectron spectroscopy (UPS).

[0051] When the perovskite solar cell is working, after the perovskite layer is exposed to light, the internal electrons gain energy and break free from the constraints of the light-absorbing layer to form negatively charged electron carriers, and at the same time form positively charged hole carriers, thereby obtaining electron-hole pairs. Free electrons and free holes are transmitted in opposite directions through the corresponding transport layer, so that electrons and holes flow, forming external current, and realizing the conversion of light energy into electrical energy. Further, after the perovskite layer absorbs photons, it is stimulated to generate electron-hole pairs, and the electron-hole pairs further dissociate to form free carriers with opposite charges. The free electrons are transmitted to the positive electrode through the electron transport layer, and the free holes are transmitted to the negative electrode through the hole transport layer. The two free carriers are collected by the corresponding electrodes respectively, and further form photocurrent in the circuit of the perovskite battery.

[0052] It is understandable that the charge extraction layer can be an electron transport layer or a hole transport layer.

[0053] Optionally, the perovskite solar cell comprises a perovskite layer, a buffer layer and a charge extraction layer stacked in sequence. The buffer layer contains an N-type semiconductor material.

[0054] Optionally, the perovskite solar cell comprises a perovskite layer, a buffer layer and a charge extraction layer stacked in sequence. The buffer layer contains a P-type semiconductor material.

[0055] Optionally, the perovskite solar cell comprises a perovskite layer, a buffer layer and a charge extraction layer stacked in sequence, wherein the buffer layer contains a passivation material.

[0056] In some embodiments, the buffer layer contains a passivation material. By introducing the passivation material, on the basis of protecting the surface of the perovskite layer, a better field effect passivation effect can be achieved on the perovskite layer, further reducing the surface defects of the perovskite layer, and further improving the photoelectric conversion effect of the perovskite solar cell. In addition, from the perspective of the preparation process of the perovskite cell, the introduction of a buffer layer containing a passivation material can reduce the damage to the perovskite layer during the preparation of the subsequent functional layer. For example, when preparing a perovskite solar cell, it is necessary to prepare a charge extraction layer on the surface of the perovskite layer. At this time, by introducing a buffer layer containing a passivation material, the damage to the perovskite layer during the preparation of the charge extraction layer can be reduced, and the performance stability of the perovskite layer can be improved, which is conducive to further improving the photoelectric conversion efficiency of the perovskite solar cell.

[0057] Optionally, the thickness of the buffer layer is 0.5 nm to 30 nm. When the thickness of the buffer layer is within this range, it can effectively promote the transmission of carriers while maintaining a good passivation effect, and further improve the stability of the photoelectric conversion efficiency of the perovskite solar cell. . Further optionally, the thickness of the buffer layer is 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm or 30 nm, etc.

[0058] As some optional examples of passivation materials, the passivation material includes at least one of silicon oxide and aluminum oxide. Silicon oxide and aluminum oxide can have a good field effect passivation effect on the perovskite layer, and can also reduce the damage to the perovskite layer when the functional layer is subsequently prepared. Further, silicon oxide includes SiO2. Aluminum oxide includes Al2O3.

[0059] In some embodiments, the passivation material includes a quantum dot passivation material. The quantum dot passivation material has a smaller particle size, which is convenient for preparing the buffer layer in a variety of ways. Optionally, when the passivation material includes a quantum dot passivation material, the buffer layer can be prepared by a solution method. This can further reduce the impact on the perovskite layer during the preparation of the perovskite solar cell, which is conducive to further improving the photoelectric conversion efficiency stability of the perovskite solar cell. Further optionally, the passivation material is a quantum dot passivation material.

[0060] It is understood that the solution method may include spin coating, doctor blade coating, slot coating, and thermal evaporation.

[0061] In some embodiments, the particle size of the passivation material is 3nm to 8nm. When the particle size of the passivation material is within this range, it is more convenient to use a solution method to prepare the corresponding buffer layer. Optionally, the particle size of the passivation material can be 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, etc.

[0062] In some embodiments, the charge extraction layer includes an electron transport layer, and the buffer layer includes an N-type semiconductor material.

[0063] In traditional perovskite solar cells, the electron transport layer may be prepared using fullerenes and their derivatives, and metal oxides. Although fullerenes and their derivatives and metal oxides have good performance, fullerenes and their derivatives are difficult to effectively block ion migration, and the cost of fullerenes and their derivatives is relatively high. Compared with fullerenes and their derivatives, metal oxides have lower costs, but when metal oxides are used, it is often necessary to form an electron transport layer on the surface of the perovskite layer by deposition. The deposition requires the use of higher energy, which may damage the surface of the perovskite layer and restrict the improvement of the photoelectric conversion efficiency of the perovskite solar cell. Therefore, the use of fullerenes and their derivatives and metal oxides has certain limitations, and it is difficult to further improve the stability of the photoelectric conversion efficiency of perovskite solar cells.

[0064] In this embodiment, by providing a buffer layer containing an N-type semiconductor material between the electron transport layer and the perovskite layer, the transmission of carriers between the perovskite layer and the electron transport layer can be promoted, which is conducive to further improving the photoelectric conversion efficiency of the perovskite solar cell. At the same time, providing a buffer layer containing an N-type semiconductor material between the electron transport layer and the perovskite layer can have a good passivation and energy level regulation effect on the surface of the perovskite layer, which can further improve the stability of the photoelectric conversion efficiency of the perovskite solar cell. In addition, providing a buffer layer containing an N-type semiconductor material between the electron transport layer and the perovskite layer can reduce the damage to the surface of the perovskite layer by subsequent processes, which is conducive to further improving the stability of the photoelectric conversion efficiency of the perovskite solar cell.

[0065] Optionally, the N-type semiconductor material includes at least one of cadmium sulfide, cadmium selenide, cadmium telluride, zinc sulfide, zinc selenide and zinc telluride. These N-type semiconductor materials can further have a good passivation and energy level regulation effect on the surface of the perovskite layer, and improve the stability of the photoelectric conversion efficiency of the perovskite solar cell. At the same time, these N-type semiconductor materials are widely available and easy to obtain. It is understandable that cadmium sulfide includes CdS. Cadmium selenide includes CdSe. Cadmium telluride includes CdTe. Zinc sulfide includes ZnS. Zinc selenide includes ZnSe. Zinc telluride includes ZnTe.

[0066] Further optionally, the N-type semiconductor material includes a quantum dot N-type semiconductor material. The quantum dot N-type semiconductor material has a smaller particle size, which is convenient for preparing the buffer layer in a variety of ways. Optionally, when the N-type semiconductor material includes a quantum dot N-type semiconductor material, the buffer layer can be prepared by a solution method. This can further reduce the impact on the perovskite layer during the preparation of the perovskite solar cell, which is conducive to further improving the stability of the photoelectric conversion efficiency of the perovskite solar cell. Further optionally, the N-type semiconductor material is a quantum dot N-type semiconductor material.

[0067] Further optionally, the particle size of the N-type semiconductor material is 3nm to 8nm. When the particle size of the N-type semiconductor material is within this range, it is more convenient to use a solution method to prepare a corresponding buffer layer. Optionally, the particle size of the N-type semiconductor material can be 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, etc.

[0068] In some embodiments, the surface of the N-type semiconductor material has a first modifying group, and the first modifying group includes a thiol group and / or an amino group. In this case, the first modifying group can cooperate with the N-type semiconductor material to passivate the surface defects of the perovskite layer, further improving the performance of the perovskite solar cell. Optionally, the thiol group includes a thiol group with a carbon chain. The amino group includes an amino group with a carbon chain.

[0069] Optionally, the molar ratio of the first modifying group to the N-type semiconductor material is 1:(10-1000). The molar ratio of the first modifying group to the N-type semiconductor material within this range can better synergistically passivate the surface defects of the perovskite layer, which is beneficial to improve the performance of the perovskite solar cell. Further optionally, the molar ratio of the first modifying group to the N-type semiconductor material is 1:10, 1:50, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:600, 1:700, 1:800, 1:900 or 1:1000, etc.

[0070] In some embodiments, the charge extraction layer includes an electron transport layer, and the buffer layer contains an N-type semiconductor material. The thickness of the buffer layer is 5nm to 20nm. The thickness of the buffer layer is within this range, which can enable the perovskite solar cell to maintain a relatively stable photoelectric conversion rate, and at the same time, the perovskite solar cell can maintain a more suitable thickness, which is conducive to promoting the use and promotion of perovskite solar cells. Optionally, the thickness of the buffer layer is 5nm, 8nm, 10nm, 12nm, 15nm, 18nm, 20nm, etc. Further optionally, the charge extraction layer is an electron transport layer. Further optionally, the buffer layer is an N-type semiconductor material layer.

[0071] In some embodiments, the electron transport layer contains a first metal oxide. The metal oxide has a low cost for preparing the electron transport layer, which is conducive to reducing the manufacturing cost of the perovskite solar cell. Optionally, the first metal oxide includes at least one of tin oxide, zinc oxide, titanium oxide and germanium oxide. Tin oxide, zinc oxide, titanium oxide and germanium oxide have good electron transport properties, and their sources are relatively wide and easy to obtain. It is understandable that tin oxide includes SnO2. Zinc oxide includes ZnO. Titanium oxide includes TiO2. Germanium oxide includes GeO.

[0072] In some embodiments, the charge extraction layer includes a hole transport layer, and the buffer layer contains a P-type semiconductor material. By providing a buffer layer containing a P-type semiconductor material between the hole transport layer and the perovskite layer, the transmission of carriers between the perovskite layer and the hole transport layer can be promoted, which is conducive to further improving the stability of the photoelectric conversion efficiency of the perovskite solar cell. Optionally, the P-type semiconductor material includes at least one of lead sulfide and lead selenide. These P-type semiconductor materials can further have a good passivation and energy level regulation effect on the surface of the perovskite layer, and improve the stability of the photoelectric conversion efficiency of the perovskite solar cell. At the same time, these N-type semiconductor materials are widely available and easy to obtain. It is understandable that lead sulfide includes PbS. Lead selenide includes PbSe.

[0073] Further optionally, the P-type semiconductor material includes a quantum dot P-type semiconductor material. The quantum dot P-type semiconductor material has a smaller particle size, which is convenient for preparing the buffer layer in a variety of ways. Optionally, when the P-type semiconductor material includes a quantum dot P-type semiconductor material, the buffer layer can be prepared by a solution method. This can further reduce the impact on the perovskite layer during the preparation of the perovskite solar cell, which is conducive to further improving the stability of the photoelectric conversion efficiency of the perovskite solar cell. Further optionally, the P-type semiconductor material is a quantum dot P-type semiconductor material.

[0074] Further optionally, the particle size of the P-type semiconductor material is 3nm to 8nm. When the particle size of the P-type semiconductor material is within this range, it is more convenient to use a solution method to prepare a corresponding buffer layer. Optionally, the particle size of the P-type semiconductor material can be 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, etc.

[0075] In some embodiments, the surface of the P-type semiconductor material has a second modifying group, and the second modifying group includes a thiol group and / or an amino group. The second modifying group can cooperate with the P-type semiconductor material to passivate the surface defects of the perovskite layer, further improving the performance of the perovskite solar cell.

[0076] Optionally, the molar ratio of the second modifying group to the P-type semiconductor material is 1:(10-1000). The molar ratio of the second modifying group to the P-type semiconductor material within this range can better synergistically passivate the surface defects of the perovskite layer, which is beneficial to improve the performance of the perovskite solar cell. Further optionally, the molar ratio of the second modifying group to the P-type semiconductor material is 1:10, 1:50, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:600, 1:700, 1:800, 1:900 or 1:1000, etc.

[0077] In some embodiments, the hole transport layer contains a second metal oxide. The metal oxide has a low cost for preparing the hole transport layer, which is conducive to reducing the manufacturing cost of the perovskite solar cell. Optionally, the second metal oxide includes at least one of nickel oxide and molybdenum oxide. Nickel oxide and molybdenum oxide have good hole transport properties, and their sources are relatively wide and easy to obtain. It is understandable that nickel oxide includes NiO. Molybdenum oxide includes MO3.

[0078] In some embodiments, the charge extraction layer includes a hole transport layer, and the buffer layer contains a P-type semiconductor material. The thickness of the buffer layer is 0.5nm to 30nm. When the thickness of the buffer layer is within this range, the perovskite solar cell can maintain a relatively stable photoelectric conversion rate, and at the same time, the perovskite solar cell can maintain a relatively suitable thickness, which is conducive to promoting the use and promotion of perovskite solar cells. Further optionally, the charge extraction layer is a hole transport layer. Further optionally, the buffer layer is a P-type semiconductor material layer. Specifically, the thickness of the buffer layer can be 1nm, 5nm, 10nm, 15nm, 20nm, 25nm or 30nm, etc.

[0079] It is understood that when preparing the buffer layer, the buffer layer material can be added to the perovskite precursor solution to form the buffer layer in situ on the surface of the perovskite layer. The buffer layer can also be formed on the surface of the perovskite layer by a solution method.

[0080] It is understood that the perovskite layer includes a material having a chemical formula of ABX3 or A2CDX6, wherein:

[0081] A is an inorganic or organic or organic-inorganic mixed cation, comprising at least one of an organic amine cation, a Cs cation, a K cation, a Rb cation and a Li cation; the organic amine cation is selected from (NR1R2R3R4) + 、(R1R2N=CR3R4) + 、(R1R2N-C(R5)=NR3R4) + or (R1R2N-C(NR5R6)=R3R4) +, wherein R1, R2, R3, R4, R5 and R6 are each independently selected from H, substituted or unsubstituted C1-20 alkyl or substituted or unsubstituted aryl; A is optionally methylamino (CH3NH3 + )(MA + ), carboxamidino (HC(NH2)2 + )(FA + ), cesium ion (Cs + ) and rubidium (Rb + ), further optionally methylamino (CH3NH3 + ) or carboxamidino (HC(NH2)2 + ).

[0082] B is an inorganic or organic or organic-inorganic mixed cation, including at least one of lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum and europium, and optionally a divalent metal ion Pb 2+ and Sn 2+ At least one of .

[0083] C is an inorganic or organic or organic-inorganic mixed cation, optionally a monovalent metal ion Ag. + wait.

[0084] D is an inorganic or organic or organic-inorganic mixed cation, optionally a trivalent metal ion bismuth cation Bi 3+ 、Antimony cation Sb 3+ 、Indium cation In 3+ wait.

[0085] X is an inorganic or organic or organic-inorganic mixed anion, optionally one or more of a halogen anion and a carboxylate anion, and further optionally a bromide ion (Br - ) or iodide ion (I - ).

[0086] In some embodiments, the thickness of the perovskite layer is 100 nm-1000 nm; as an example, the thickness of the perovskite layer can be but is not limited to 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm or a range between any two of the above values.

[0087] In some embodiments, the band gap of the perovskite layer is 1.2 eV to 2.3 eV. As an example, the band gap of the perovskite layer is 1.2 eV, 1.3 eV, 1.4 eV, 1.5 eV, 1.6 eV, 1.7 eV, 1.8 eV, 1.9 eV, 2 eV, 2.1 eV, 2.2 eV, 2.3 eV, or a range between any two of the above values. When the band gap of the perovskite layer is within the above range, it can have a higher visible light absorption efficiency.

[0088] In some embodiments, the material of the perovskite layer includes Cs (0～0.05) FA (0.8～0.95) MA (0～0.10) PbI (2.7～3) Br (0～0.1) Optionally, the material of the perovskite layer includes Cs 0.05 FA 0.93 MA 0.02 PbI 2.94 Br 0.06 .

[0089] In some embodiments, the material of the electron transport layer may include, but is not limited to, one or more of the following materials and their derivatives: imide compounds, quinone compounds, fullerenes and their derivatives, methoxytriphenylamine-fluoroformamidine (OMeTPA-FA), calcium titanate (CaTiO3), lithium fluoride (LiF), calcium fluoride (CaF2), poly (3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT:PSS), poly 3-hexylthiophene (P3HT), triphenylamine (H101) with triptycene as the core, 3, 4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-phenylamino)carbazole-spirobifluorene (CzPAF-SBF), polythiophene, metal oxides, silicon oxide (SiO2), strontium titanate (SrTiO3), cuprous thiocyanate (CuSCN), etc.; wherein the metal elements may include one or more of Mg, Ni, Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr.

[0090] In some embodiments, the material of the hole transport layer may include, but is not limited to, one or more of the following materials and their derivatives: 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), nickel oxide (NiO x ), poly 3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT:PSS), WO3 and other materials can transport holes and block electrons.

[0091] It can be understood that the perovskite solar cell also includes a transparent electrode layer and a metal electrode layer, the transparent electrode layer is located on the side of the perovskite layer away from the buffer layer, and the metal electrode layer is located on the side of the charge extraction layer away from the buffer layer. By setting the transparent electrode layer and the metal electrode layer, a formal perovskite solar cell and an inverted perovskite solar cell can be obtained.

[0092] Optionally, the transparent electrode layer is selected from at least one of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), indium zinc oxide (IZO) and indium tungsten oxide (IWO). Optionally, the thickness of the transparent electrode layer is 100nm to 1000nm, and further optionally 300nm to 800nm.

[0093] Optionally, the metal electrode layer is selected from at least one of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W and alloys thereof. Optionally, the thickness of the metal electrode layer is 20nm to 200nm, optionally 60nm to 100nm, and further optionally 70nm to 90nm.

[0094] It is understood that the perovskite solar cell also includes a substrate layer. A transparent electrode layer is formed on the substrate layer. The substrate layer includes a glass substrate and a flexible substrate. The material of the flexible substrate layer may be, for example, (but not limited to) an organic polymer material. Further, the material of the flexible substrate layer may be mixed by one or more of the following materials in different proportions: including but not limited to polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), etc.

[0095] It is understood that perovskite solar cells include formal perovskite solar cells and inverted perovskite solar cells. For formal perovskite solar cells, formal perovskite solar cells include a transparent electrode layer and an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode layer stacked in sequence on the transparent electrode layer. For inverted perovskite solar cells, inverted perovskite solar cells include a transparent electrode layer and a hole transport layer, a perovskite layer, an electron transport layer and a metal electrode layer stacked in sequence on the transparent electrode layer.

[0096] It is understandable that other functional layers, such as a basic buffer layer, can be introduced into the perovskite solar cell as required.

[0097] In some embodiments, a perovskite solar cell may be provided with a basic buffer layer with a suitable energy level, which may play one or more of the roles of reducing energy level barriers, promoting energy level matching, improving carrier extraction efficiency, passivating interface defect states, protecting light absorption layers, inhibiting water molecules, oxygen oxidation and decomposition of batteries, improving photoelectric conversion efficiency, and improving the stability of perovskite solar cells. Depending on the location of the basic buffer layer, the types of basic buffer layers may include four types: a basic buffer layer between a hole transport layer and an anode, a basic buffer layer between an electron transport layer and a cathode, a basic buffer layer between a hole transport layer and an absorption layer, and a basic buffer layer between an electron transport layer and an absorption layer. Materials that can be used for the basic buffer layer in a perovskite solar cell may include, but are not limited to, Cu2O, NiO, AZO, TiO2, and the like.

[0098] See also Figure 1 , which shows the structure of a perovskite solar cell 100 in one embodiment of the present application. The perovskite solar cell 100 includes a substrate layer 101, a transparent electrode layer 102, a hole transport layer 103, a perovskite layer 104, a buffer layer 105, an electron transport layer 106 and a metal electrode layer 107 stacked in sequence. The buffer layer 105 contains an N-type semiconductor material or a passivation material.

[0099] See also Figure 2 , which shows the structure of a perovskite solar cell 200 in another embodiment of the present application. The perovskite solar cell 200 includes a substrate layer 201, a transparent electrode layer 202, an electron transport layer 203, a perovskite layer 204, a buffer layer 205, a hole transport layer 206 and a metal electrode layer 207 stacked in sequence. The buffer layer 205 contains a P-type semiconductor material or a passivation material.

[0100] Another embodiment of the present application provides an electrical device, characterized in that it includes the above-mentioned perovskite solar cell.

[0101] In some embodiments, the perovskite solar cell can be used as a power generation device of an electrical device. The type of the power generation device can include but is not limited to integrated power generation. The location of the power generation device can include but is not limited to the roof, back panel, etc. of a car.

[0102] Furthermore, the above-mentioned electrical devices may include mobile devices, such as mobile phones, laptop computers, etc., electric vehicles, electric trains, ships and satellites, power generation systems, etc., but are not limited thereto.

[0103] Figure 3 The power consumption device 300 is an automobile, and may further be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.

[0104] As another example, the electric device may be a mobile phone, a tablet computer, a laptop computer, a calculator, etc.

[0105] As another example, the power-consuming device may be a wearable device, such as a watch.

[0106] Example

[0107] In order to make the technical problems, technical solutions and beneficial effects solved by the present application clearer, the present application will be further described in detail below in conjunction with the embodiments and drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its applications. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0108] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0109] Example 1

[0110] The perovskite solar cell in this embodiment has Figure 1 The structure shown. The preparation method of the perovskite solar cell is: a NiO layer with a thickness of 30nm is prepared on FTO by magnetron sputtering. Then, a perovskite precursor solution is spin-coated on the surface of the NiO layer to form a perovskite layer with a thickness of 600nm. The material of the perovskite layer is Cs 0.05 FA 0.93 MA 0.02 PbI 2.94 Br 0.06 A buffer layer with a thickness of 10 nm is formed on the surface of the perovskite layer by using a solution method with a quantum dot CdS material with a particle size of 5 nm. A SnO2 layer with a thickness of 30 nm is deposited on the surface of the buffer layer. A copper electrode layer with a thickness of 100 nm is then formed on the surface of the SnO2 layer by thermal evaporation.

[0111] Example 2

[0112] Compared with Example 1, the difference of this example is that the quantum dot CdS material is a quantum dot CdS material modified with mercaptopropionic acid. The surface of the quantum dot CdS material has a thiol group, and the molar ratio of the thiol group to CdS is 1:500.

[0113] Example 3

[0114] Compared with Example 1, the difference of this embodiment is that the quantum dot CdS material is replaced by the quantum dot ZnS material.

[0115] Example 4

[0116] Compared with Example 1, the difference of this embodiment is that the quantum dot CdS material is replaced with a quantum dot SiO2 material, and the thickness of the buffer layer is 20 nm.

[0117] Example 5

[0118] The perovskite solar cell in this embodiment has Figure 2 The structure shown. The preparation method of the perovskite solar cell is:

[0119] A SnO2 layer with a thickness of 30 nm was prepared on FTO using magnetron sputtering. Then, a perovskite precursor solution was spin-coated on the surface of the SnO2 layer to form a perovskite layer with a thickness of 600 nm. The material of the perovskite layer was Cs 0.05 FA 0.93 MA 0.02 PbI 2.94 Br 0.06 A 10nm thick buffer layer is formed on the surface of the perovskite layer by using a solution method with a quantum dot PbS material with a particle size of 5nm. A 30nm thick NiO layer is then deposited on the surface of the buffer layer. A 100nm thick copper electrode layer is then formed on the surface of the NiO layer by thermal evaporation.

[0120] Example 6

[0121] Compared with Example 5, the difference of this example is that the quantum dot PbS material is an oleylamine-modified quantum dot PbS material, and the molar ratio of amino group to PbS is 1:1000.

[0122] Example 7

[0123] Compared with Example 5, the difference of this embodiment is that the quantum dot PbS material is replaced with a quantum dot SiO2 material, and the thickness of the buffer layer is 5 nm.

[0124] Comparative Example 1

[0125] Compared with Example 1, the difference of this comparative example is that no buffer layer is prepared, that is, there is no buffer layer between the perovskite layer and the metal oxide layer.

[0126] Comparative Example 2

[0127] Compared with Example 1, the difference of this comparative example is that no buffer layer is prepared, and a PCBM layer is formed on the surface of the perovskite layer.

[0128] Comparative Example 3

[0129] Compared with Example 5, the difference of this comparative example is that no buffer layer is prepared, that is, there is no buffer layer between the perovskite layer and the hole transport layer.

[0130] Test Case

[0131] The initial photoelectric conversion efficiency of the perovskite solar cells obtained in the embodiment and the comparative example and the photoelectric conversion efficiency after 500 hours of light aging were tested respectively. The photoelectric conversion efficiency test method is to test the JV characteristic curve of the perovskite solar cell under AM1.5 standard sunlight; the light aging experiment is carried out by exposing the device to 1 standard sunlight. The test results are shown in Table 1.

[0132] Table 1

[0133] Initial photoelectric conversion efficiency Photoelectric conversion efficiency after 500h light aging Example 1 19.8％ 18.2％ Example 2 20.5％ 20.8％ Example 3 20.0％ 19.5％ Example 4 19.6％ 21.1％ Example 5 16.9％ 17.2％ Example 6 17.5％ 16.3％ Example 7 16.8％ 17.7％ Comparative Example 1 6.5％ 2.8％ Comparative Example 2 21.3％ 13.9％ Comparative Example 3 2.3％ 1.5％

[0134] It can be seen from Table 1 that the perovskite solar cells of Examples 1 to 7 have higher photoelectric conversion efficiency than Comparative Examples 1 and 3. Compared with Comparative Example 2, the perovskite solar cells of Examples 1 to 7 can maintain higher and more stable photoelectric conversion efficiency after 500 hours of light aging. This shows that the photoelectric conversion efficiency of the perovskite solar cell can be effectively improved by setting the corresponding buffer layer in Examples 1 to 7, and the stability of the photoelectric conversion efficiency during light aging can be effectively improved.

[0135] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A perovskite solar cell, characterized in that: It comprises a perovskite layer, a buffer layer and a charge extraction layer which are stacked in sequence; the buffer layer contains an N-type semiconductor material or a P-type semiconductor material or a passivation material.

2. The perovskite solar cell according to claim 1, characterized in that The buffer layer contains a passivation material, and the thickness of the buffer layer is 0.5 nm to 30 nm.

3. The perovskite solar cell according to claim 1 or 2, characterized in that: The passivation material includes at least one of silicon oxide and aluminum oxide; Optionally, the passivation material comprises a quantum dot passivation material; Optionally, the particle size of the passivation material is 3nm to 8nm.

4. The perovskite solar cell according to claim 1, characterized in that: The charge extraction layer includes an electron transport layer, and the buffer layer contains an N-type semiconductor material.

5. The perovskite solar cell according to claim 4, characterized in that: The N-type semiconductor material includes at least one of cadmium sulfide, cadmium selenide, cadmium telluride, zinc sulfide, zinc selenide and zinc telluride.

6. The perovskite solar cell according to claim 4 or 5, characterized in that: The N-type semiconductor material includes quantum dot N-type semiconductor material; Optionally, the particle size of the N-type semiconductor material is 3 nm to 8 nm.

7. The perovskite solar cell according to any one of claims 4 to 6, characterized in that The surface of the N-type semiconductor material has a first modification group, and the first modification group includes a thiol group and / or an amino group; Optionally, the molar ratio of the first modifying group to the N-type semiconductor material is 1:(10-1000).

8. The perovskite solar cell according to any one of claims 4 to 7, characterized in that The thickness of the buffer layer is 5nm-20nm.

9. The perovskite solar cell according to any one of claims 4 to 8, characterized in that The electron transport layer contains a first metal oxide; Optionally, the first metal oxide includes at least one of tin oxide, zinc oxide, titanium oxide and germanium oxide.

10. The perovskite solar cell according to claim 1, characterized in that: The charge extraction layer includes a hole transport layer, and the buffer layer contains a P-type semiconductor material.

11. The perovskite solar cell according to claim 10, characterized in that: The P-type semiconductor material includes at least one of lead sulfide and lead selenide.

12. The perovskite solar cell according to claim 10 or 11, characterized in that: The P-type semiconductor material includes quantum dot P-type semiconductor material; Optionally, the particle size of the P-type semiconductor material is 3nm to 8nm.

13. The perovskite solar cell according to any one of claims 10 to 12, characterized in that: The surface of the P-type semiconductor material has a second modification group, and the second modification group includes a thiol group and / or an amino group; Optionally, the molar ratio of the second modifying group to the P-type semiconductor material is 1:(10-1000).

14. The perovskite solar cell according to any one of claims 10 to 13, characterized in that The hole transport layer contains a second metal oxide; Optionally, the second metal oxide includes at least one of nickel oxide and molybdenum oxide.

15. The perovskite solar cell according to any one of claims 10 to 14, characterized in that The thickness of the buffer layer is 0.5 nm to 30 nm.

16. The perovskite solar cell according to any one of claims 1 to 15, characterized in that The perovskite solar cell further includes a transparent electrode layer and a metal electrode layer. The transparent electrode layer is located on a side of the perovskite layer away from the buffer layer, and the metal electrode layer is located on a side of the charge extraction layer away from the buffer layer.

17. An electrical device, characterized in that: A perovskite solar cell comprising the perovskite solar cell according to any one of claims 1 to 16.

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