Perovskite solar cell and preparation method therefor, photovoltaic module, power generation device, and electric device

Abstract

The present disclosure provides a perovskite solar cell and a preparation method therefor, a photovoltaic module, a power generation device, and an electric device. The perovskite solar cell comprises a first electrode and a second electrode. A perovskite layer and an electron transport layer are sequentially arranged between the first electrode and the second electrode in a first direction, wherein the electron transport layer partially covers the perovskite layer, and the first direction is a light incident direction.

Description

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

[0001] Cross-reference to Related Applications

[0002] The present disclosure is based on and claims priority to Chinese Patent Application No. 202410643082.5, filed on May 22, 2024, entitled “Perovskite solar cell, preparation method thereof, photovoltaic module, power generation device and power utilization device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of batteries, and in particular to a perovskite solar cell, a preparation method thereof, a photovoltaic module, a power generation device and a power utilization device. BACKGROUND

[0004] With the development of modern industry, global energy shortage and environmental pollution problems are becoming increasingly prominent, and solar cells, as an ideal renewable energy source, are receiving more and more attention. Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through photoelectric or photochemical effects.

[0005] Perovskite solar cells are a type of new solar cells that are currently widely studied. They have gradually become a hot topic in the research of new generation solar cells due to their high photoelectric conversion efficiency, simple manufacturing process, low production cost and material cost, and other advantages. However, the current perovskite solar cells still need to be further improved in terms of photoelectric conversion efficiency. SUMMARY

[0006] The present disclosure is made in view of the above-mentioned problems, and aims to provide a perovskite solar cell, a photovoltaic module, a power generation device and a power utilization device with good photoelectric conversion efficiency.

[0007] To achieve the above-mentioned purpose, the present disclosure provides, in a first aspect, a perovskite solar cell, comprising: a first electrode and a second electrode, between which a perovskite layer and an electron transport layer are arranged in sequence along a first direction, wherein the electron transport layer partially covers the perovskite layer; the first direction is the light incidence direction. Through the present disclosure, the electron transport layer partially covers the perovskite layer, on the one hand, the interface between the perovskite layer and the electron transport layer can realize point contact, reducing the contact area between the interface of the perovskite layer and the electron transport layer, and reducing the occurrence of non-radiative recombination caused by interface contact, on the other hand, the thickness of the electron transport layer can be reduced, which helps to improve the transmission efficiency of the electron transport layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell, and saving costs.

[0008] In some embodiments, the coverage of the electron transport layer on the perovskite layer is 30%-90%. In some embodiments, the coverage of the electron transport layer on the perovskite layer is 42%-62%. In this way, the coverage of the electron transport layer on the perovskite layer is within the above range, which is conducive to fully realizing the point contact between the perovskite layer and the interface of the electron transport layer, and more conducive to improving the electron transport efficiency of the electron transport layer, and further improving the photoelectric conversion efficiency of the perovskite solar cell.

[0009] In some embodiments, the root mean square roughness of the perovskite layer is 8 nm-40 nm. In this way, it is conducive to forming a partially covered electron transport layer on the perovskite layer, thereby improving the electron transport efficiency.

[0010] In some embodiments, the electron transport layer comprises an electron transport material, and the electron transport material comprises at least one of a fullerene and a derivative thereof, a metal oxide, and a metal fluoride.

[0011] In some embodiments, the fullerene and the derivative thereof comprise one or more of fullerene C 60 , fullerene C 70 , [6,6]-phenyl C61 butyric acid methyl ester, [6,6]-phenyl C71 butyric acid methyl ester, and indene-C60 bisadduct; or, the metal oxide comprises one or both of tin dioxide and zinc oxide; or, the metal fluoride comprises one or both of lithium fluoride and calcium fluoride.

[0012] The second aspect of the present disclosure provides a method for preparing a perovskite solar cell, comprising the following steps: forming a perovskite layer on a first electrode; forming an electron transport layer on the perovskite layer, the electron transport layer partially covering the perovskite layer; and forming a second electrode on the electron transport layer.

[0013] The present disclosure forms an electron transport layer partially covering the perovskite layer on the perovskite layer, thereby facilitating the point contact between the electron transport layer and the perovskite, reducing the occurrence of non-radiative recombination due to interface contact, improving the electron transport efficiency, and saving costs.

[0014] In some embodiments, the coverage of the electron transport layer on the perovskite layer is 30%-90%. In this way, it is conducive to fully realizing the contact between the perovskite layer and the interface of the electron transport layer, and more conducive to improving the electron transport efficiency.

[0015] In some embodiments, forming the electron transport layer on the perovskite layer comprises: while forming a wet film of the electron transport layer ink on the perovskite layer by slot coating, performing air knife treatment. By using slot coating and air knife treatment in combination, the electron transport layer can be uniformly distributed on the perovskite layer and partially cover the perovskite layer.

[0016] In some embodiments, the thickness of the wet film is 6 μm or less. By setting the thickness of the wet film to be 6 μm or less, in combination with the use of slit coating and air knife processing, the coverage of the electron transport layer on the perovskite layer is controlled, which is conducive to improving the electron transport layer rate.

[0017] In some embodiments, the air knife processing air output is 60-200 ul / s. By controlling the air output of the air knife processing, the coverage of the electron transport layer on the perovskite is controlled, which is conducive to improving the photoelectric conversion efficiency of the perovskite solar cell.

[0018] In some embodiments, the concentration of the electron transport layer ink is 5-30 mg / ml, the injection speed of the slit coating is 70-300 ul / s, and the moving speed of the slit coating is 10-100 mm / s.

[0019] By controlling the above conditions, the electron transport layer is more evenly distributed on the perovskite layer and the coverage of the electron transport layer on the perovskite layer is controlled.

[0020] The third aspect of the present disclosure provides a photovoltaic module, which comprises the perovskite solar cell provided in the first aspect or prepared according to the preparation method provided in the second aspect.

[0021] Since the photovoltaic module of the present disclosure comprises the above-mentioned perovskite solar cell of the present disclosure, it at least has the same advantages as the perovskite solar cell.

[0022] The fourth aspect of the present disclosure provides a power generation device, which comprises the perovskite solar cell provided in the first aspect or prepared according to the preparation method provided in the second aspect.

[0023] Since the power generation device of the present disclosure comprises the above-mentioned perovskite solar cell of the present disclosure, it at least has the same advantages as the perovskite solar cell.

[0024] The fifth aspect of the present disclosure provides a power consumption device, which comprises the perovskite solar cell provided in the first aspect or prepared according to the preparation method provided in the second aspect.

[0025] Since the power consumption device of the present disclosure comprises the above-mentioned perovskite solar cell of the present disclosure, it at least has the same advantages as the perovskite solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0026] FIG. 1 is a structural schematic diagram of a perovskite solar cell according to an embodiment of the present disclosure.

[0027] FIG. 2 is an SEM color block analysis diagram of the perovskite solar cell of Example 1 of the present disclosure after forming an electron transport layer.

[0028] FIG. 3 is a surface potential map obtained in KPFM characterization of the perovskite solar cell of Example 1 of the present disclosure.

[0029] FIG. 4 is an SEM color patch analysis map of the perovskite solar cell of Comparative Example 1 of the present disclosure after forming the electron transport layer.

[0030] Reference numerals: 10 perovskite solar cell; 11 first electrode; 12 second electrode; 13 perovskite layer; 14 electron transport layer. DETAILED DESCRIPTION

[0031] Hereinafter, specific embodiments of the perovskite solar cell and the method for manufacturing the same, the photovoltaic module, the power generation device, and the power consumption device of the present disclosure are specifically disclosed with appropriate reference to the accompanying drawings. However, there will be cases where unnecessary detailed description is omitted. For example, there will be cases where detailed description of matters known well and repeated description of substantially 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 accompanying drawings and the following description are provided so that those skilled in the art can fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0032] The "range" disclosed in the present disclosure is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting one lower limit and one upper limit, and the selected lower limit and upper limit define the boundaries of a specific range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if the ranges 60-120 and 80-110 are listed for a particular parameter, it is understood that the ranges 60-110 and 80-120 are also contemplated. 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 are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present disclosure, unless otherwise stated, the numerical range "a-b" represents a shorthand notation for any real combination of integers 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" have been listed herein, and "0-5" is just a shorthand notation for these numerical combinations. In addition, when it is stated that a certain parameter is an integer ≥ 2, it is equivalent to disclose that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0033] Unless otherwise specified, all embodiments of the present disclosure and optional embodiments can be combined with each other to form new technical solutions.

[0034] If not specifically mentioned, all technical features and optional technical features of the present disclosure can be combined with each other to form new technical solutions.

[0035] If not specifically mentioned, all steps of the present disclosure can be performed in sequence or randomly, and preferably in sequence. For example, a method comprising steps (a) and (b) means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, it is mentioned that the method can further comprise step (c), which means that step (c) can be added to the method in any order. For example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0036] If not specifically mentioned, the terms used in the present disclosure have the commonly understood meanings understood by those skilled in the art.

[0037] If not specifically mentioned, the values of the parameters mentioned in the present disclosure can be measured by various test methods commonly used in the art, for example, can be measured according to the test methods given in the present disclosure.

[0038] The term "layer" used in the present disclosure refers to any substantially layer-like structure. The layer can have a thickness that varies over the extent of the layer. Typically, the layer has a thickness that is approximately constant. The "thickness" of a layer used in the present disclosure refers to the average thickness of the layer. The thickness of the layer can be easily measured using conventional methods.

[0039] If not specifically mentioned, the present disclosure refers to a layer on / over another layer includes the case where the first layer is directly on the second layer, i.e., the two layers are in direct contact, and the case where there is an intervening layer (such as a third layer) between the first layer and the second layer.

[0040] The term "perovskite" used in the present disclosure refers to a material having a three-dimensional crystal structure related to that of CaTiO3, or a layer material including a structure related to that of CaTiO3. Materials having a three-dimensional crystal structure related to that of CaTiO3 are well known, and can be referred to as perovskites having a "3D perovskite structure", or "3D perovskites". When receiving sunlight, electrons in the perovskite are excited, and the electrons transition from the valence band to the conduction band to form electron-hole pairs. If not specifically mentioned, the present disclosure refers to "perovskite" as a 3D perovskite material. The perovskite can be represented by the general chemical formula ABX3, where A is typically a large radius cation. For example, A includes: CH(NH2)2 + , CH3NH3 + , K + , Rb +at least one of Cs + B is a smaller radius cation, B includes, but is not limited to, Pb 2+ , Sn 2+ , Mg 2+ , Ca 2+ , Ba 2+ , Zn 2+ , Ge 2+ , Co 2+ X is an anion, for example, X includes at least one of Cl - , Br - , I - , SCN - , CNO - , OCN - , OSCN - , SH - , OH - , CP - , CN - , SeCN - When the perovskite includes more than one A cation, the different A cations can be ordered or disordered on the A sites. When the perovskite includes more than one B cation, the different B cations can be ordered or disordered on the B sites. When the perovskite includes more than one X anion, the different X anions can be ordered or disordered on the X sites.

[0041] A solar cell, also known as a photovoltaic cell, is a device that converts light energy directly into electricity by the photoelectric effect or photochemical effect. Among them, the perovskite solar cell has good optical absorption coefficient, luminescence quantum efficiency, low-cost manufacturing process and many other advantages, and has strong application potential. However, the photoelectric conversion efficiency of the perovskite solar cell still needs to be improved.

[0042] In view of this, the present disclosure provides a perovskite solar cell and a preparation method thereof, as well as a photovoltaic module, a power generation device and a power utilization device comprising the perovskite solar cell.

[0043] The perovskite solar cell

[0044] The perovskite solar cell provided by the present disclosure comprises a first electrode and a second electrode, and a perovskite layer and an electron transport layer are arranged in sequence between the first electrode and the second electrode along a first direction, wherein the electron transport layer partially covers the perovskite layer; the first direction is a light incidence direction.

[0045] It is generally believed in the industry that the electron transport layer needs to completely cover the perovskite layer to improve the electron transport efficiency. However, it is found through research that the complete coverage of the electron transport layer on the perovskite layer means that a very thick electron transport layer needs to be formed, and the too thick film layer is not conducive to electron transport, thereby affecting the photoelectric conversion efficiency of the perovskite solar cell.

[0046] It is found through further research that, in the working of the perovskite solar cell, the perovskite layer generates electron-hole pairs under light irradiation, and the transport of electrons is mainly realized at the grain boundaries of the perovite layer. Based on this, in the present disclosure, the electron transport layer effectively covers the perovskite grain boundaries of the perovskite layer, although complete coverage is not achieved at the peak of the perovskite crystal, but the interface between the perovskite layer and the electron transport layer can realize point contact, and still can provide sufficient transport channels for the electrons generated in the perovskite layer. Moreover, since the electron transport layer only needs to partially cover the perovskite layer, the finally formed electron transport layer is relatively thin, so it not only helps to improve the transport efficiency of the electron transport layer, thereby improving the photoelectric conversion efficiency of the cell, but also can save costs.

[0047] FIG. 1 is a schematic structural diagram of a perovskite solar cell according to an embodiment of the present disclosure. As shown in FIG. 1, the perovskite solar cell 10 includes a first electrode 11 and a second electrode 12, and a perovskite layer 13 and an electron transport layer 14 are arranged in sequence between the first electrode 11 and the second electrode 12 along the light incident direction (i.e., the first direction), wherein the electron transport layer 14 partially covers the perovskite layer 13.

[0048] In some embodiments, the coverage rate of the electron transport layer on the perovskite layer is 30%-90%. When the coverage rate of the electron transport layer on the perovskite layer is within the above range, the electron transport layer can sufficiently cover the grain boundaries of the perovskite layer, which is conducive to providing sufficient electron transport channels and improving the electron transport efficiency of the electron transport layer. For example, the coverage rate of the electron transport layer on the perovskite layer can be 30%, 40%, 42%, 46%, 50%, 54%, 55%, 60%, 62%, 65%, 70%, 72%, 75%, 80%, 90%, or a value within a range between any two of the above values. Alternatively, the coverage rate of the electron transport layer on the perovskite layer is 42%-62%.

[0049] In the present disclosure, the coverage rate of the electron transport layer is measured by using a scanning electron microscope (SEM) image chroma analysis method. The electron transport layer of the perovskite solar cell is analyzed by using a scanning electron microscope, and a scanning SEM image is obtained. The SEM image is analyzed by using an image analysis software, such as colorpix software, to identify the RBG value of each pixel, to distinguish the covered area and the uncovered area, to take multiple samples to obtain the average value, and to calculate the coverage rate.

[0050] Exemplarily, FIG. 2 is an SEM image taken after forming an electron transport layer on the perovskite layer according to an embodiment of the present disclosure, black represents the grain boundary, dark gray represents the well-covered part, and light gray represents the poorly-covered part. According to the RGB three-color identification method, the present disclosure defines black and dark gray as the first color (covered area) and light gray as the second color (uncovered area). By comparing the RGB colors, it is found that the chroma values of the R, G, and B three-color channels of the SEM image under black and white display are relatively close, and therefore the chroma average value of the RGB three colors is used to represent the color, i.e. RGB average value = (R channel chroma value + B channel chroma value + G channel chroma value) / 3. When the maximum value of the RGB average value of the first color and the minimum value of the RGB average value of the second color differ by 20, the first color and the second color can be distinguished. After processing by the image analysis software, the RGB average value of 80-120 is defined as the first color, and the RGB average value of 140-180 is defined as the second color. In the present disclosure, the coverage of the electron transport layer on the perovskite layer is the proportion of the area of the color block of the first color to the total color block area.

[0051] There is a potential difference of 100 mV-200 mV between the surface of the electron transport layer and the surface of the perovskite layer not covered by the electron transport layer. The surface potential of the region covered by the electron transport layer on the perovskite layer is 100 mV-200 mV higher than that of the region not covered by the electron transport layer. Exemplarily, the surface potential of the surface of the electron transport layer is 100 mV, 120 mV, 140 mV, 160 mV, 180 mV, 200 mV or a value between any two of them higher than that of the surface not covered by the electron transport layer.

[0052] In the present disclosure, the surface potential refers to the potential difference at the interface of two phases due to the difference in ion or electron mobility. The surface potential can be measured by Kelvin probe force microscopy (KPFM) technology. The presence of a potential difference indicates that the electron transport layer does not completely cover the perovskite layer.

[0053] In some embodiments, the electron transport layer described above comprises an electron transport material. There is no particular limitation on the electron transport material, for example, at least one of fullerene and derivatives thereof, metal oxide, and metal fluoride. Further, the fullerene and derivatives thereof include fullerene C 60 , fullerene C 70, one or several of [6,6]-phenyl C61 butyric acid methyl ester (PC61BM), [6,6]-phenyl C71 butyric acid methyl ester (PC71BM), indene-C60 bisadduct (ICBA), or other fullerene derivatives; one or several of metal oxides including tin dioxide (SnO2), zinc oxide (ZnO), and the like; one or several of metal fluorides including lithium fluoride (LiF), calcium fluoride (CaF2), and the like.

[0054] In some embodiments, the perovskite layer as the light-absorbing layer includes a perovskite material. The present disclosure does not have a particular limitation on the perovskite material included in the perovskite layer, which can be selected according to actual needs. The perovskite material can have a molecular formula of ABX3or A2CDX6, where A represents an inorganic cation, an organic cation, or an organic-inorganic hybrid cation, exemplarily one or more of (NR1R2R3R4) + , (R1R2N=CR3R4) + , (R1R2N-C(R5)=NR3R4) + , and (R1R2N-C(NR5R6)=NR3R4) + , where R1, R2, R3, R4, R5, and R6are each independently selected from H, a substituted or unsubstituted C1-C20 alkyl, or a substituted or unsubstituted aryl. Optionally, the perovskite material includes, but is not limited to, the following materials: methylamino (CH3NH3 + ), formamidinium (HC(NH2)2 + ), dimethylammonium cation, ethylammonium cation, propylammonium cation, butylammonium cation, pentylammonium cation, hexylammonium cation, imidazolium cation, cesium ion (Cs + ), lithium ion (Li + ), sodium ion (Na + ), potassium ion (K + ), silver ion (Ag + ), and rubidium (Rb + ), and the like; B represents a divalent metal cation, including, but not limited to, the following materials: lead ion (Pb 2+ ), divalent tin ion (Sn 2+ ), beryllium ion (Be 2+ ), magnesium ion (Mg 2+ ), calcium ion (Ca 2+ ), strontium ion (Sr 2+ ), barium ion (Ba 2+ ), zinc ion (Zn 2+ ), germanium ion (Ge 2+ ), ferrous ion (Fe 2+ ), divalent manganese ion (Mn 2+ ), divalent cobalt ion (Co 2+divalent copper ions (Cu 2+ ) and divalent nickel ions (Ni 2+ ), etc.; more optionally, the B ions include one or both of lead ions (Pb 2+ ), divalent tin ions (Sn 2+ ); C represents monovalent metal cations, such as one or both of sodium ions (Na + ), potassium ions (K + ), silver ions (Ag + ) and rubidium ions (Rb + ), etc.; D represents trivalent metal cations, including but not limited to: trivalent bismuth ions (Bi 3+ ), trivalent antimony ions (Sb 3+ ), trivalent chromium ions (Cr 3+ ), trivalent iron ions (Fe 3+ ), trivalent cobalt ions (Co 3+ ), trivalent gallium ions (Ga 3+ ), trivalent arsenic ions (As 3+ ), trivalent ruthenium ions (Ru 3+ ), trivalent rhodium ions (Rh 3+ ), etc.; X represents monovalent anions, such as halogen ions or halogen-like ions, including but not limited to: chloride ions (Cl - ), bromide ions (Br - ), iodide ions (I - ), SCN - , BF4 - , HCO2 - , SeCN - , CN - , etc. Exemplarily, the perovskite material includes at least one of inorganic halide materials, organic halide materials, organic-inorganic halide perovskite materials. In some embodiments, the perovskite material includes at least one of CH3NH3PbI3 (abbreviated as MAPbI3), CH(NH2)2PbI3 (abbreviated as FAPbI3), Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3 (abbreviated as CsFAMA), CsPbI3, CsPbI2Br, CsPbIBr2.

[0055] In some embodiments, the perovskite layer described above can be prepared by the following steps: dissolving perovskite material precursor raw materials in a solvent to prepare a perovskite precursor solution, and then coating the perovskite precursor solution onto a sample to be coated by a coating method, and drying and annealing to prepare the perovskite layer.

[0056] Optionally, the perovskite material precursor raw material includes AX, BX2, wherein A, B, X are defined as described above, such as AX compounds (FA represents CH(NH2)2 + , MA represents CH3NH3 + ) such as CsI, FAI, MAI, MACl, etc.

[0057] Optionally, the solvent for preparing the perovskite precursor solution can include one or more of N, N-dimethylformamide (abbreviation: DMF), dimethyl sulfoxide (abbreviation: DMSO), chlorobenzene.

[0058] In some embodiments, the temperature of the annealing treatment is 90-150°C. For example, the temperature of the annealing treatment can be 90°C, 92°C, 95°C, 98°C, 100°C, 102°C, 105°C, 108°C, 110°C, 120°C, 128°C, 130°C, 140°C, and any value within the range defined by any two of the above values.

[0059] In some embodiments, the time of the annealing treatment is 5-30 min. Optionally, the time of the annealing treatment can be 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 20 min, 25 min, 30 min, and any value within the range defined by any two of the above values.

[0060] The coating method includes slit coating, doctor blade coating, etc., which are not limited here.

[0061] In some embodiments, the drying can be achieved by vacuum drying.

[0062] In another embodiment, the perovskite layer can be prepared by a gas phase method or a gas-liquid method, which are not limited here.

[0063] The roughness of the perovskite layer is not particularly limited in the present disclosure, and the roughness commonly used in the art can be used. The roughness of the perovskite layer can be represented by, for example, the root mean square roughness. The root mean square roughness (RMS) is a kind of physical quantity representing the degree of unevenness of the surface, and generally represents the root mean square value of the surface height, which can be calculated using the formula RMS = (1 / N)∑(|hi|), wherein RMS represents the root mean square roughness, N represents the number of measurement points, and hi represents the height of each measurement point. The surface height can be measured by, for example, a laser interferometer, an atomic force microscope, etc.

[0064] In some embodiments, the root mean square roughness of the perovskite layer is between 8 nm and 40 nm. The root mean square roughness of the perovskite layer in the above range is beneficial for forming a partially covering electron transport layer on the perovskite layer, and enables the electron transport layer to sufficiently cover the grain boundaries of the perovskite layer, providing sufficient electron transport channels, thereby improving the electron transport efficiency. Illustratively, the root mean square roughness of the perovskite layer can be 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, or a value between a range defined by any two of the values. In some embodiments, the root mean square roughness of the perovskite layer can be adjusted by changing the solvent of the perovskite precursor solution, adjusting the time of vacuum drying, annealing temperature and time, and the like. Illustratively, increasing the boiling point of the solvent of the perovskite precursor solution can reduce the root mean square roughness of the perovskite layer.

[0065] The thickness of the perovskite layer is not particularly limited in the present disclosure, and a thickness conventionally used in the art can be employed. Illustratively, the thickness of the perovskite layer can be between 400 nm and 1500 nm, such as 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1200 nm, 1500 nm, or a value between a range defined by any two of the values.

[0066] In some embodiments, other functional layers, such as a passivation layer, can be further provided between the perovskite layer and the electron transport layer. It can be understood that the other functional layer does not completely cover the perovskite layer. In embodiments in which other functional layers are further provided between the perovskite layer and the electron transport layer, the coverage of the electron transport layer on the perovskite layer can be understood as the coverage of the electron transport layer on the surface formed by the perovskite layer and the other functional layers provided thereon. Illustratively, the material of the passivation layer can include at least one of piperazine, N-methyl-1,3-propanediammonium diiodide, 3-aminopyridine, ferrocene, and homologues or derivatives thereof; the thickness of the passivation layer is generally between 0.5 nm and 2.5 nm.

[0067] In some embodiments, the first electrode described above can also be referred to as a bottom electrode, which is the electrode that first receives incident light, for collecting electrons / holes. The material of the first electrode includes a transparent conductive material. The present disclosure does not particularly limit the transparent conductive material included in the first electrode. Illustratively, the transparent conductive material includes at least one of tin oxide, 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.

[0068] In some embodiments, the second electrode described above can also be referred to as a top electrode, which is the electrode that receives incident light and collects electrons / holes. The second electrode can employ a conductive material. The present disclosure does not particularly limit the conductive material included in the second electrode. For example, the conductive material includes at least one of an organic conductive material, an inorganic conductive material, wherein the inorganic conductive material includes at least one of the transparent conductive material described above, a metal and an alloy thereof, a carbon elemental material. Exemplarily, the metal and the alloy thereof include at least one of gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, tungsten. Exemplarily, the carbon elemental material includes at least one of graphite, graphene, carbon nanotube. Exemplarily, the organic conductive material includes at least one of poly(3,4-ethylenedioxythiophene), polythiophene, polyacetylene.

[0069] In some embodiments, the perovskite solar cell described above can further include a hole transport layer including a hole transport material. The present disclosure does not particularly limit the hole transport material. Exemplarily, the hole transport material includes, but is not limited to, nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS), 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, poly-3-hexylthiophene, triptycene-core triphenylamine, 3,4-ethylenedioxythiophene-methoxy triphenylamine, N-(4-aniline)carbazole-spirofluorene, polythiophene, phosphonic monomer and its polymer, carbazolyl monomer and its polymer, sulfonic monomer and its polymer, triphenylamine monomer and its polymer, aromatic monomer and its polymer, cuprous iodide, and cuprous thiocyanate. The present disclosure does not particularly limit the thickness of the hole transport layer, and a thickness of the hole transport layer commonly used in the art can be employed.

[0070] In some embodiments, the perovskite solar cell described above can further include a lower passivation layer. The lower passivation layer is disposed on a lower surface of the perovskite layer described above. The present disclosure does not particularly limit the material of the lower passivation layer, and a material commonly used in the art can be employed. Exemplarily, the lower passivation layer can include a π-π conjugated self-assembled molecule, and a molecule that can be anchored to the perovskite layer at one end, such as 3-triethoxysilylpropionitrile, 2-aminothiazole-4-acetic acid, 1-hydroxy-4-carbonylbenzene, but is not limited thereto.

[0071] In some embodiments, the perovskite solar cell described above can further include an upper passivation layer. The upper passivation layer is disposed on the upper surface of the perovskite layer. The present disclosure does not have a particular limitation on the material of the upper passivation layer, and a material commonly used in the art can be used. Illustratively, the material of the upper passivation layer can include piperazine, N-methyl-1,3-propanediammonium diiodide, 3-aminopyridine, ferrocene, etc., but is not limited thereto.

[0072] In some embodiments, the perovskite solar cell described above can further include a blocking layer. The present disclosure does not have a particular limitation on the material of the blocking layer, and a material commonly used in the art can be used. Illustratively, the material of the blocking layer can include indium tungsten oxide (IWO), indium tin oxide (ITO), bathocuproin (BCP), tin oxide, zirconium acetylacetonate, but is not limited thereto.

[0073] Method of manufacturing perovskite solar cell

[0074] The perovskite solar cell of the present disclosure can be manufactured by the following method. The manufacturing method includes: forming a perovskite layer on a first electrode; forming an electron transport layer on the perovskite layer, the electron transport layer partially covering the perovskite layer; and forming a second electrode on the electron transport layer.

[0075] In some embodiments, the coverage of the electron transport layer on the perovskite layer described above is 30-90%. When the coverage of the electron transport layer on the perovskite layer is within the above range, the electron transport layer sufficiently covers the grain boundaries of the perovskite layer, which is advantageous in providing sufficient electron transport channels and improving the electron transport efficiency of the electron transport layer. Illustratively, the coverage of the electron transport layer on the perovskite layer described above can be 30%, 40%, 42%, 46%, 50%, 54%, 55%, 60%, 62%, 65%, 70%, 72%, 75%, 80%, 90%, or a value between any two of them. In some embodiments, the coverage of the electron transport layer on the perovskite layer described above is 42-62%.

[0076] The method of forming the electron transport layer on the perovskite layer is not particularly limited, as long as it can make the electron transport layer partially cover the perovskite layer. In some embodiments, forming the electron transport layer on the perovskite layer described above includes: while forming a wet film by applying the electron transport layer ink on the perovskite layer through slot coating, performing air knife treatment.

[0077] Slot coating is a coating technique that uses an extremely fine nozzle and a high-precision coating system to apply viscous liquid or paste-like materials to specific locations on a product. The present disclosure uses slot coating to more accurately distribute the electron transport layer ink on the perovskite layer. In addition, the use of slot coating can improve the material utilization rate of the electron transport layer ink, and improve the quality and efficiency of the coating.

[0078] The air knife is driven by a high-pressure fan to send out uniform and strong hot air, thereby achieving the purpose of drying. The present disclosure uses an air knife to quickly dry the wet film of the electron transport layer ink coated on the perovskite layer, quickly reaches the saturation critical point, and precipitates the crystal of the electron transport material to form a dry film at the grain boundary of the perovskite layer. Due to the existence of protrusions and depressions on the surface of the perovskite layer, the use of an air knife can prevent the electron transport layer ink from flowing to the depressions, so that the surface of the perovskite layer in the depressions is completely covered by the electron transport layer, and the protrusions on the surface of the perovskite layer are not completely covered by the electron transport layer.

[0079] The present disclosure forms an electron transport layer on the perovskite layer by slot coating combined with air knife treatment, so that the electron transport layer can be uniformly distributed on the perovskite layer, and the electron transport layer partially covers the perovskite layer, so that the electron transport layer covers the grain boundary of the perovskite layer, providing sufficient electron transport channels to achieve effective electron transport efficiency.

[0080] In some embodiments, the wet film formed by the above-mentioned electron transport layer ink on the above-mentioned perovskite layer has a thickness of less than or equal to 6 μm. Exemplarily, the wet film formed by the electron transport layer ink on the above-mentioned perovskite layer can have a thickness of 0.5 μm, 0.67 μm, 0.88 μm, 1 μm, 1.75 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 6 μm, or a value between any two of them. When the wet film formed by the electron transport layer ink on the perovskite layer has a thickness within the above-mentioned range, the wet film can form an ultra-thin and partially covering perovskite layer after air knife treatment.

[0081] In some embodiments, the air knife treatment has an air output of 60 ul / s-200 ul / s. Controlling the air output of the air knife treatment within the above-mentioned range helps to control the appropriate coverage of the electron transport layer on the perovskite layer, thereby improving the transmission efficiency of the electron transport layer and the photoelectric conversion efficiency of the perovskite solar cell. Exemplarily, the air knife treatment can have an air output of 60 ul / s, 80 ul / s, 90 ul / s, 100 ul / s, 120 ul / s, 150 ul / s, 160 ul / s, 200 ul / s, or a value between any two of them.

[0082] In some embodiments, the above-mentioned electron transport layer ink includes an electron transport material and a solvent, wherein the electron transport material is as described above and is not repeated here; as a solvent, it includes one or more of chlorobenzene and o-dichlorobenzene. The combination of the above-mentioned electron transport material and solvent can provide good electrical conductivity, and the formed electron transport layer ink is suitable for slot coating, easy to process, and easy to quickly dry by air knife treatment to form a uniformly distributed electron transport layer dry film.

[0083] In some embodiments, the concentration of the electron transport layer ink described above is 5-30 mg / ml. The concentration of the electron transport layer ink within the range described above allows the electron transport layer ink to have a suitable viscosity, which is beneficial for application to the slot coating method, and improves the precision and efficiency of coating. Illustratively, the concentration of the electron transport layer ink described above can be 5 mg / ml, 10 mg / ml, 15 mg / ml, 20 mg / ml, 25 mg / ml, 30 mg / ml, or a value between any two of these values. In some embodiments, the concentration of the electron transport layer ink described above is 8-20 mg / ml, optionally 10-20 mg / ml.

[0084] In some embodiments, the injection speed of the slot coating method described above is 70-300 ul / s. Illustratively, the injection speed of the slot coating method described above can be 70 ul / s, 100 ul / s, 140 ul / s, 200 ul / s, 240 ul / s, 300 ul / s, or a value between any two of these values. In some embodiments, the moving speed of the coating die of the slot coating method described above is 10-100 mm / s. Illustratively, the moving speed of the slot coating described above can be 10 mm / s, 30 mm / s, 50 mm / s, 80 mm / s, 90 mm / s, 100 mm / s, or a value between any two of these values.

[0085] In the present disclosure, by appropriately adjusting the injection speed and moving speed of the slot coating method described above within the range described above, and the air output of the air knife treatment, the electron transport layer is covered at the grain boundaries of the perovskite layer, and partially covers the perovskite layer, so that the electron transport layer provides an effective electron transport channel, and improves the electron transport efficiency.

[0086] In some embodiments, the injection speed of the slot coating method described above is 100-240 ul / s, optionally 140-240 ul / s; the moving speed is 60-100 mm / s, optionally 80-100 mm / s; and the air output of the air knife treatment described above is 70-200 ul / s, optionally 90-160 ul / s.

[0087] For the amount of the electron transport layer coated by the slot coating and air knife treatment as described above, it is equivalent to coating an electron transport layer with a thickness of 10 nm-20 nm on a substrate that is almost completely flat, for example, the substrate can be a smooth and flat pure glass. By the above-mentioned treatment, an electron transport layer that partially covers the perovskite layer can be formed, and the resulting electron transport layer covers at the grain boundaries of the perovskite layer.

[0088] The present disclosure does not make special restrictions on the preparation of the first electrode, which can be obtained commercially or can be prepared by methods commonly used in the art.

[0089] The preparation method of the hole transport layer is not particularly limited in the present disclosure, and a method conventionally used in the art can be adopted. Illustratively, the preparation of the hole transport layer can adopt a spin coating method, a vapor deposition method (e.g., a magnetron sputtering method), or the like.

[0090] The preparation method of the perovskite layer is not particularly limited in the present disclosure, and a method conventionally used in the art can be adopted. Illustratively, the preparation of the perovskite layer can adopt a liquid phase method such as a spin coating method, a slot coating method, or a doctor blade coating method, or a vapor phase method such as evaporation, or a combination of a gas phase and a liquid phase.

[0091] The preparation method of the second electrode is not particularly limited in the present disclosure, and a method conventionally used in the art can be adopted. Illustratively, the preparation of the second electrode can adopt a magnetron sputtering method, an evaporation method, or the like.

[0092] In addition, the present disclosure also provides a photovoltaic module. Generally, the photovoltaic module includes the perovskite solar cell described above, a solder strip connecting a plurality of perovskite solar cells, a junction box for current transmission, and a cell packaging component.

[0093] In some embodiments, the cell packaging component includes a photovoltaic glass, which covers the perovskite solar cell described above and protects the perovskite solar cell. At the same time, the photovoltaic glass has very good light transmittance and very high hardness, and can adapt to a large diurnal temperature range and harsh weather conditions.

[0094] In some embodiments, the cell packaging component includes an ethylene-vinyl acetate copolymer (EVA) film, which is arranged between the photovoltaic glass and the perovskite solar cell and is used to bond the photovoltaic glass and the solar cell.

[0095] In some embodiments, the cell packaging component includes a photovoltaic backsheet, which also protects the perovskite solar cell.

[0096] Optionally, the material of the photovoltaic backsheet can be a polyvinyl fluoride composite film or a thermoplastic elastomer. The material of the photovoltaic backsheet has the characteristics of insulation, waterproofness, and aging resistance.

[0097] In some embodiments, the cell packaging component includes a solar aluminum frame, which includes an aluminum alloy material and has the characteristics of high strength and good corrosion resistance. The solar aluminum frame can support and protect the solar cell.

[0098] In addition, the present disclosure also provides a power generation device including the perovskite solar cell provided in the above embodiments.

[0099] In addition, the present disclosure also provides an electric device including the perovskite solar cell provided in the above embodiments.

[0100] In some embodiments, the power consuming device can also be a lighting device, an energy storage device, etc., including but not limited to the same. For example, the power consuming device can be a solar water heater, a solar street lamp, a solar photovoltaic generator, etc.

[0101] Embodiments

[0102] Hereinafter, embodiments of the present disclosure will be described. The embodiments described below are exemplary and are for the purpose of explaining the present disclosure only and should not be understood as limiting the present disclosure. Unless otherwise specified, the reagents used are commercially available, and the equipment used is conventional equipment.

[0103] The present disclosure will be further illustrated by the following examples.

[0104] Example 1

[0105] Preparation of perovskite solar cell:

[0106] 1) Preparation of the first electrode: FTO glass with a size of 30*30 cm 2 was cleaned with water, acetone, and isopropanol several times by ultrasonic cleaning, and then dried with nitrogen for standby; then the FTO conductive glass cleaned and dried as above was treated with ultraviolet ozone for standby.

[0107] 2) Preparation of the hole transport layer: a thickness of about 20 nm of NiOx was formed on the above first electrode by magnetron sputtering, and annealed at 300°C for 60 min to obtain the hole transport layer.

[0108] 3) Preparation of the perovskite layer: a one-step method was used to prepare the perovskite light absorbing material. 0.05 mol of CsI, 0.95 mol of FAI, and 1 mol of PbI2 were weighed and placed in 666 ml of DMF, stirred at room temperature for 6 h, filtered with a 0.22 um filter, and loaded into a coating machine. The above prepared perovskite light absorbing material was placed in an oven and annealed at 140°C for 20 min to obtain a perovskite layer FA 0.9 Cs 0.1 PbI3 with a thickness of 500 nm. The root mean square roughness of the obtained perovskite layer was 35 nm, as determined by atomic force microscopy (AFM).

[0109] 4) Preparation of the electron transport layer: 100 mg of PC 61The BM was mixed with 10 ml of chlorobenzene solution and stirred at 500 rpm for 8 hours to prepare an electron transport layer ink (concentration 10 mg / ml). The electron transport layer ink was coated on the perovskite layer using a slot coating method, in which the coating die moving speed was 100 mm / s and the injection speed was 200 ul / s. A wind knife was set behind the coating head and moved with the coating machine to dry the material while coating, in which the wind knife air speed was 120 uL / s to form the electron transport layer.

[0110] 5) Preparation of the second electrode: The above-mentioned sheet with the electron transport layer was placed in an evaporation instrument, and the evaporation vacuum degree was maintained at 5*10 -4 A 80 nm metal back electrode Cu was evaporated at a rate of 0.1 A / s under a pressure of 10 Pa to obtain a perovskite solar cell.

[0111] Colorimetric analysis of perovskite solar cells

[0112] The above-mentioned sheet with the electron transport layer was scanned using a scanning electron microscope of a Zeiss Gemini SEM to obtain SEM images. The obtained SEM images were analyzed using colorpix software to identify the colorimetric values of R, G, and B channels of each pixel, and the RGB average value of each pixel was calculated by the formula RGB average value = (R channel colorimetric value + B channel colorimetric value + G channel colorimetric value) / 3. According to the RGB average value, the area covered by the electron transport layer (i.e. the first color) and the area not covered by the electron transport layer (the second color) were distinguished, and then the coverage rate of the electron transport layer was calculated using the formula: electron transport layer coverage rate = first color patch area / (first color patch area + second color patch area) * 100%. See Figure 2 for details.

[0113] Surface potential test of perovskite solar cells

[0114] The above-mentioned sheet with the electron transport layer was subjected to surface potential test using a BRUKER Kelvin probe force microscope (KPFM) to obtain a KPFM map. See Figure 3 for details.

[0115] As shown in Figure 3, there is a potential difference between the surface of the area covered by the above-mentioned electron transport layer and the surface of the area not covered by the above-mentioned electron transport layer on the perovskite layer. The existence of the potential difference indicates that the electron transport layer does not completely cover the perovskite layer.

[0116] Device test of perovskite solar cells

[0117] Keithley 2400 SMU was used to test the device. AM1.5G solar irradiation was used at 1000 W / m 2The prepared perovskite solar cells were tested under the light source. The Keithley 2400 SMU anode was connected to the perovskite solar cell anode (i.e. the hole end), and the cathode was connected to the perovskite solar cell cathode (i.e. the electron end). The starting voltage was set to -0.1 V, the ending voltage was set to 1.2 V, and the scanning mode was set to reverse scan. The measured cell output power (P out ), incident light power (P opt ) were recorded respectively. The energy conversion efficiency of the perovskite cell was calculated using the following formula: PCE = P out / P opt

[0118] Example 2-13

[0119] The perovskite solar cells were prepared according to the method of Example 1, except that different coverages were obtained by adjusting the process parameters in step 4), and the specific values are shown in Table 1.

[0120] The performance test was carried out according to the same method as Example 1, and the test results are shown in Table 1.

[0121] Example 14

[0122] The perovskite solar cells were prepared according to the method of Example 1, except that the solvent DMF in step 3) was replaced by a mixed solvent of DMSO / DMF with a volume ratio of 1:9, and the root mean square roughness of the obtained perovskite layer was 8 nm.

[0123] Example 15

[0124] The perovskite solar cells were prepared according to the method of Example 1, except that the annealing temperature in step 3) was replaced by 120°C, and the root mean square roughness of the obtained perovskite layer was 40 nm.

[0125] Example 16

[0126] The perovskite solar cells were prepared according to the method of Example 1, except that a step of preparing a passivation layer was added between step 3) and step 4), and the specific,

[0127] A piperazine iodine isopropyl alcohol solution (concentration 0.5 mg / mL) was coated on the above perovskite layer using a slot coating method, the coating die moving speed was 50 mm / s, the liquid injection speed was 300 ul / s, and the air knife drying was used to obtain the upper passivation layer with a thickness of about 2 nm. Then an electron transport layer ink was coated on the above upper passivation layer using a slot coating method, and the rest was the same as Example 1.

[0128] Comparative Example 1

[0129] A perovskite solar cell was prepared according to the method of Example 1, except that in step 5) the electron transport layer completely covered the perovskite layer, with a coverage of 100%. The SEM color block analysis diagram of the electron transport layer thereof is shown in FIG. 4.

[0130] Performance tests were performed in the same manner as in Example 1, and the test results are shown in Table 1.

[0131] Table 1

[0132] As can be seen from the data in Table 1, compared with the perovskite solar cell of Comparative Example 1 in which the electron transport layer completely covers the perovskite layer, the perovskite solar cell of the present disclosure has improved photoelectric conversion efficiency by allowing the electron transport layer to partially cover the perovskite layer.

[0133] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having substantially the same configuration and playing the same role and effect as the technical idea within the scope of the technical solutions of the present disclosure are all included in the technical scope of the present disclosure. Furthermore, within the scope of the main idea of the present disclosure, various modifications that can be thought of by those skilled in the art are applied to the embodiments, and other modes constructed by combining part of the constituent elements of the embodiments are also included in the scope of the present disclosure.

Claims

1. A perovskite solar cell, comprising a first electrode and a second electrode, between which a perovskite layer and an electron transport layer are arranged in sequence along a first direction, wherein, The electron transport layer partially covers the perovskite layer; the first direction is the light incident direction.

2. The perovskite solar cell of claim 1, wherein, The coverage of the electron transport layer on the perovskite layer is 30%-90%.

3. The perovskite solar cell according to claim 1 or 2, wherein The coverage of the electron transport layer on the perovskite layer is 42%-62%.

4. The perovskite solar cell according to any one of claims 1 to 3, wherein The root mean square roughness of the perovskite layer is 8nm-40nm.

5. The perovskite solar cell according to any one of claims 1 to 4, wherein The surface of the electron transport layer and the surface of the perovskite layer not covered by the electron transport layer have a potential difference of 100mV-200mV.

6. The perovskite solar cell according to any one of claims 1 to 5, wherein The electron transport layer comprises an electron transport material, the electron transport material comprising at least one of fullerene and derivatives thereof, metal oxide, metal fluoride.

7. The perovskite solar cell of claim 6, wherein, The fullerenes and derivatives thereof include one or more of fullerenes C 60 , fullerenes C 70 , [6,6]-phenyl C61 butyric acid methyl ester, [6,6]-phenyl C71 butyric acid methyl ester, indene-C60 bisadduct.

8. The perovskite solar cell of claim 6, wherein, The metal oxide comprises one or both of tin dioxide and zinc oxide.

9. The perovskite solar cell of claim 6, wherein, The metal fluoride comprises one or both of lithium fluoride and calcium fluoride.

10. A method for preparing a perovskite solar cell, comprising the following steps: forming a perovskite layer on a first electrode; forming an electron transport layer on the perovskite layer, the electron transport layer partially covering the perovskite layer; and forming a second electrode on the electron transport layer.

11. The production method according to claim 10, wherein The coverage of the electron transport layer on the perovskite layer is 30%-90%.

12. The production method according to claim 11, wherein The coverage of the electron transport layer on the perovskite layer is 42%-62%.

13. The production method according to any one of claims 10 to 12, wherein, Forming an electron transport layer on the perovskite layer comprises: while forming a wet film on the perovskite layer by slot coating of an electron transport layer ink, performing air knife treatment.

14. The production method according to claim 13, wherein The thickness of the wet film is 6μm or less.

15. The method of manufacturing according to claim 14, wherein, The air knife treatment has an air output of 60-200ul / s.

16. The method of manufacturing according to claim 15, wherein, The concentration of the electron transport layer ink is 5-30mg / ml, the injection speed of the slot coating is 70-300ul / s, and the moving speed of the slot coating is 10-100mm / s.

17. The production method according to claim 15 or 16, wherein The air knife treatment has an air output of 70-200ul / s; the injection speed of the slot coating is 100-240ul / s; and the moving speed is 60-100mm / s.

18. A photovoltaic module comprising the perovskite solar cell of any one of claims 1 to 9 or prepared by the method of any one of claims 10 to 17.

19. A power generation device comprising the perovskite solar cell of any one of claims 1 to 9 or prepared by the method of any one of claims 10 to 17.

20. An electric device comprising the perovskite solar cell of any one of claims 1 to 9 or prepared by the method of any one of claims 10 to 17.

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