Laminated solar cell, photovoltaic module, power generation device and power utilization device

Abstract

The invention provides a laminated solar cell, a photovoltaic module and an electric device. The laminated solar cell comprises a first electrode, at least two cell units and a second electrode which are sequentially arranged in a laminated mode in the first direction, the at least two cell units comprise the first cell unit and the second cell unit, the first cell unit comprises a first light absorption layer and a first electron transport layer which are sequentially arranged in the first direction, and the second cell unit comprises a second light absorption layer and a second electron transport layer which are sequentially arranged in the second direction. The second cell unit comprises a second hole transport layer and a second light absorption layer which are sequentially arranged along the first direction; wherein the first electron transport layer and the second hole transport layer are adjacent to each other and are arranged in a mutual contact manner, at least one of the first electron transport layer and the second hole transport layer is arranged as an array formed by columnar nano particles, nano particles are distributed on the surfaces of the columnar nano particles, and the laminated solar cell has high open-circuit voltage and photoelectric conversion efficiency.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a stacked solar cell, a photovoltaic module, a power generation device, and an electricity-consuming device. Background Art

[0002] Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric effect or photochemical effect. As an ideal renewable energy source, solar cells are receiving increasing attention.

[0003] With the development of solar cell technology, people have higher and higher requirements on the performance of solar cells. Tandem solar cells have good application prospects due to their high photoelectric conversion efficiency.

[0004] Tandem solar cells consist of at least two cells stacked in the direction of incident light. Adjacent cells are connected by a composite layer of a membrane structure. This composite layer hinders the recombination of electrons and holes, limiting the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell. Summary of the Invention

[0005] This application is based on the above-mentioned problems and aims to provide a tandem solar cell, photovoltaic module, power generation device, and power consumption device. The tandem solar cell utilizes nanoparticles distributed on the surface of each columnar nanoparticle to provide recombination sites for electrons and holes transferred to the columnar nanoparticles, thereby facilitating electron-hole recombination and achieving high open-circuit voltage and photoelectric conversion efficiency.

[0006] In order to achieve the above-mentioned purpose, the present application provides a stacked solar cell, which includes a first electrode, at least two battery cells, and a second electrode stacked in sequence along a first direction, the at least two battery cells include a first battery cell and a second battery cell, the first battery cell includes a first light absorption layer and a first electron transport layer arranged in sequence along the first direction, and the second battery cell includes a second hole transport layer and a second light absorption layer arranged in sequence along the first direction; wherein the first electron transport layer and the second hole transport layer are arranged adjacent to and in contact with each other, and at least one of the two layers is arranged as an array of columnar nanoparticles, and nanoparticles are distributed on the surface of the columnar nanoparticles. The transport layer structure in the form of a columnar nanoparticle array is beneficial to the longitudinal transport of carriers, and the nanoparticles distributed on the surface of each columnar nanoparticle provide recombination sites for electrons and holes transmitted to the columnar nanoparticles, which is beneficial to the recombination of electrons and holes. The stacked solar cell has a high open circuit voltage and photoelectric conversion efficiency.

[0007] In some embodiments, the material of the nanoparticles includes at least one of gold, indium tin oxide, indium zinc oxide, iron, cobalt, nickel, zinc, manganese, cadmium, silver, and copper. These materials have high electrical conductivity, and the use of nanoparticles containing these materials facilitates the recombination of electrons and holes.

[0008] In some embodiments, the ratio (γ) of the total surface area of ​​the nanoparticles to the total surface area of ​​the columnar nanoparticles is 50% to 90%. Controlling γ within this range can help increase the number of recombination sites while reducing or preventing the material of the functional layer above the columnar nanoparticles from penetrating into the gaps between the columnar nanoparticles.

[0009] In some embodiments, the average particle size of the nanoparticles is 1 nm to 20 nm. By controlling the average particle size of the nanoparticles within the above range, the aggregation of the nanoparticles can be reduced, which is conducive to increasing the number of recombination sites.

[0010] In some embodiments, the average particle size of the nanoparticles is 2 nm to 10 nm. By controlling the average particle size of the nanoparticles within the above range, the number of recombination sites can be further increased.

[0011] In some embodiments, the ratio (ω) of the particle size of the nanoparticles to the cross-sectional diameter of the columnar nanoparticles is 0.1 to 1. By controlling ω within the above range, the nanoparticles can achieve a better coverage effect on the surface of the columnar nanoparticles.

[0012] In some embodiments, the ratio of the particle size of the nanoparticles to the cross-sectional diameter of the columnar nanoparticles (ω) is 0.1 to 0.5. By controlling ω within the above range, the coverage of the nanoparticles on the surface of the columnar nanoparticles is further improved.

[0013] In some embodiments, the ratio (σ) of the distance between two adjacent columnar nanoparticles to the particle size of the nanoparticles is 1.5 to 3.5. By controlling σ within the above range, sufficient space can be provided for accommodating the nanoparticles while reducing the infiltration of the material of the functional layer above the columnar nanoparticles into the gaps between the columnar nanoparticles.

[0014] In some embodiments, the first electron transport layer is arranged as an array of the columnar nanoparticles, and the material used for the first electron transport layer includes at least one of fullerene compounds, TiO2, ZnO, SnO2, and carbon nanotubes. Selecting these materials facilitates the first electron transport layer's electron transport advantages while also facilitating the formation of the columnar nanoparticles.

[0015] In some embodiments, the second hole transport layer is arranged as an array composed of the columnar nanoparticles, and the material used for the second hole transport layer includes SnO x , NiO x , at least one of CuSCN, Cu2O, and CuI, where 1 < x < 2. By selecting from the above materials, while facilitating the second hole transport layer to exert the hole transport advantage, it is beneficial to the formation of the columnar nanoparticles.

[0016] In some embodiments, the cross-sectional diameter of the columnar nanoparticles is 10 nm to 50 nm, and the height of the columnar nanoparticles in the first direction is 10 nm to 30 nm. By controlling the cross-sectional diameter of the columnar nanoparticles within the above range, on the one hand, it is beneficial to form an appropriate number of columnar nanoparticles and improve the composite sites; on the other hand, it is easy to prepare and beneficial to improve the stability of the battery. By controlling the height of the columnar nanoparticles within the above range, on the one hand, it is beneficial to increase the number of nanoparticles arranged on the surface of the columnar nanoparticles, thus being beneficial to appropriate composite sites; on the other hand, it will not cause an increase in resistance.

[0017] In some embodiments, the first direction is the same as the incident direction of light.

[0018] In some embodiments, the first light absorption layer and the second light absorption layer respectively include perovskite materials. Perovskite materials have high photoelectric conversion efficiency. Compared with other tandem solar cells, the photoelectric conversion efficiency of the tandem solar cell in this embodiment is further improved.

[0019] In some embodiments, the first direction is opposite to the incident direction of light.

[0020] In some embodiments, the second light absorption layer includes perovskite materials, and the first light absorption layer includes crystalline silicon materials.

[0021] The second aspect of the present application provides a photovoltaic module, and the photovoltaic module includes the tandem solar cell provided by the first aspect.

[0022] Since the photovoltaic module of the present application includes the tandem solar cell provided by the present application, it thus has at least the same advantages as the solar cell.

[0023] The third aspect of the present application provides a power generation device, and the power generation device includes the tandem solar cell provided by the first aspect.

[0024] Since the power generation device of the present application includes the tandem solar cell provided by the present application, it thus has at least the same advantages as the solar cell.

[0025] A fourth aspect of the present application provides an electrical device, comprising the stacked solar cell provided in the first aspect.

[0026] Since the electric device of the present application includes the stacked solar cell provided by the present application, it has at least the same advantages as the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of a solar cell according to one embodiment of the present application.

[0028] Figure 2 Schematic diagram of the structure of a solar cell according to one embodiment of the present application.

[0029] Figure 3 Schematic diagram of the structure of cylindrical nanoparticle array.

[0030] Figure 4 Schematic diagram of the cross section of the nanoparticle.

[0031] Figure 5 Schematic diagram of a columnar nanoparticle array with nanoparticles distributed on the surface (front view).

[0032] Figure 6 Schematic diagram of a columnar nanoparticle array with nanoparticles distributed on the surface (top view).

[0033] Figure 7 Schematic diagram of the structure of an inverted solar cell according to one embodiment of the present application.

[0034] Figure 8 Schematic diagram of the structure of an inverted solar cell according to one embodiment of the present application.

[0035] Description of reference numerals:

[0036] 100, 300, 400 inverted solar cells; 200 formal solar cell; 11 first electrode; 12 second electrode; 13 first battery cell; 131 first hole transport layer; 132 first light absorption layer; 133 first electron transport layer; 14 second battery cell; 141 second hole transport layer; 142 second light absorption layer; 143 second electron transport layer; 144 hole blocking layer; 15 columnar nanoparticles; 16 nanoparticles. DETAILED DESCRIPTION

[0037] Below, with appropriate reference to the accompanying drawings, a detailed description of an embodiment of a stacked solar cell, photovoltaic module, and photovoltaic device of the present application is specifically disclosed. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be 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 to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0038] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this 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.

[0039] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0040] 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.

[0041] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating 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), indicating 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.

[0042] Unless otherwise specified, the terms used in this application have the common meanings generally understood by those skilled in the art.

[0043] Unless otherwise specified, the values ​​of the parameters mentioned in this application can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods given in this application.

[0044] As used herein, the term "layer" refers to any substantially layered structure. A layer may have a thickness that varies over the range over which the layer extends. Typically, a layer has an approximately constant thickness. As used herein, the term "thickness" of a layer refers to the average thickness of the layer. The thickness of a layer can be readily measured using conventional methods.

[0045] Unless otherwise specified, references in this application to a layer being on / located on another layer include the case where the first layer is directly located on the second layer, i.e., the two layers are in direct contact, as well as the case where there are other layers (such as a third layer) interposed between the first layer and the second layer.

[0046] The term "perovskite" used in this application refers to a material having a three-dimensional crystal structure related to the three-dimensional crystal structure of CaTiO3, or a layer material having a structure related to the structure of CaTiO3. Materials having a three-dimensional crystal structure related to CaTiO3 are well known and can be referred to as perovskites having a "3D perovskite structure", or as "3D perovskites". Materials containing layers of perovskite materials are well known and are referred to as "2D layered perovskites" in the art. When receiving sunlight, the electrons in the perovskite are excited, and the electrons jump from the valence band to the conduction band, generating electron-hole pairs. Unless otherwise specified, "perovskite" mentioned in this application refers to 3D perovskite materials. The general chemical formula of the perovskite can be expressed as ABX3, where A is generally a cation with a larger radius. For example, A includes CH(NH2)2 + 、CH3NH3 + , K + , Rb + 、Cs +At least one of. B is a cation with a smaller radius, including but not limited to Pb 2+ Mg 2+ , Ca 2+ 、Sn 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Co 2+ At least one of X is an anion, for example, X includes 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 may be distributed in an orderly or disordered manner on the A site. When the perovskite includes more than one B cation, the different B cations may be distributed in an orderly or disordered manner on the B site. When the perovskite includes more than one X anion, the different X anions may be distributed in an orderly or disordered manner on the X site.

[0047] Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric effect or photochemical effect. As an ideal renewable energy source, solar cells are gaining increasing attention.

[0048] With the advancement of solar cell technology, people are demanding increasingly higher performance from solar cells. Tandem solar cells consist of at least two stacked cells. By combining the band gaps of the cells, they absorb sunlight in the long-wavelength range, improving its utilization rate. Consequently, tandem solar cells achieve high photoelectric conversion efficiency.

[0049] Each cell in the stacked solar cell is equipped with a light absorption layer and a carrier transport layer (e.g., electron transport layer, hole transport layer). The light absorption layer uses a light-absorbing material (e.g., perovskite material) that can absorb photons to generate electron-hole pairs. Under the action of the electric field, the electron-hole pairs are dissociated into carriers (electrons, holes). The directional movement of the dissociated carriers forms an electric current. The presence of the carrier transport layer can enhance the dissociation effect of electrons and holes, thereby effectively improving the photoelectric conversion efficiency of the battery.

[0050] For tandem solar cells, especially all-perovskite tandem solar cells, the bottom cell typically receives incident light first, while the top cell receives incident light that passes through the bottom cell. A film-like composite layer is typically arranged between adjacent bottom and top cells to provide a recombination site for electrons generated by the light-absorbing layer of the bottom cell and holes generated by the light-absorbing layer of the top cell. However, in the composite layer of the film structure, carriers undergo lateral transport, which is not conducive to the efficient transport of carriers to the recombination site for electron and hole recombination. This reduces the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0051] In view of this, the present application provides a tandem solar cell. A photovoltaic module, a power generation device, and a power consumption device comprising the tandem solar cell are provided. The tandem solar cell utilizes a transport layer structure in the form of a columnar nanoparticle array, which facilitates the longitudinal transport of charge carriers. Nanoparticles distributed on the surface of each columnar nanoparticle provide recombination sites for electrons and holes transported to the columnar nanoparticles, facilitating electron-hole recombination. The tandem solar cell exhibits high open-circuit voltage and photoelectric conversion efficiency.

[0052] Tandem solar cells

[0053] The stacked solar cell includes a first electrode, at least two battery cells and a second electrode stacked in sequence along a first direction, the at least two battery cells include a first battery cell and a second battery cell, the first battery cell includes a first light absorption layer and a first electron transport layer arranged in sequence along the first direction, and the second battery cell includes a second hole transport layer and a second light absorption layer arranged in sequence along the first direction; wherein the first electron transport layer and the second hole transport layer are arranged adjacent to and in contact with each other, and at least one of the layers is arranged as an array of columnar nanoparticles, and nanoparticles are distributed on the surface of the columnar nanoparticles.

[0054] In the present application, no composite layer is provided between the first battery cell and the second battery cell, and the first electron transport layer and the second hole transport layer are arranged adjacent to and in contact with each other. Moreover, unlike conventional stacked batteries, at least one of the first electron transport layer and the second hole transport layer is not arranged in a film structure, but is formed into an array composed of columnar nanoparticles. The transport layer structure in the form of a columnar nanoparticle array is beneficial to the longitudinal transport of carriers, thereby greatly reducing the lateral transport of carriers. Furthermore, by providing recombination sites for electrons and holes transmitted to the columnar nanoparticles through the nanoparticles distributed on the surface of each columnar nanoparticle, it is further beneficial to the recombination of electrons and holes. Therefore, compared with the conventional stacked solar cell with a layered structure, the stacked solar cell with the above structure has improved open circuit voltage and photoelectric conversion efficiency.

[0055] The first battery unit in the present application is further provided with a first hole transport layer on a side of the first light absorption layer away from the first electron transport layer, which is conducive to the transport of holes generated by photon excitation in the light absorption layer to the first electrode.

[0056] The second battery unit in the present application is further provided with a second electron transport layer on the side of the second light absorption layer away from the second hole transport layer, which is conducive to the transmission of electrons generated by the light absorption layer excited by photons to the second electrode.

[0057] It should be noted that the tandem solar cell of the present application includes an inverted solar cell and a regular solar cell. The following further illustrates various aspects of the tandem solar cell of the present application with reference to the accompanying drawings.

[0058] Figure 1 A schematic structural diagram of a tandem solar cell (inverted solar cell 100 ) according to one embodiment is shown. Figure 2 FIG. 2 shows a schematic structural diagram of a stacked solar cell (formally a solar cell 200) according to another embodiment. Figure 1 and Figure 2 As shown, the stacked solar cell includes a first electrode 11, at least two battery cells and a second electrode 12 stacked in sequence along a first direction, the at least two battery cells include a first battery cell 13 and a second battery cell 14, the first battery cell 13 includes a first hole transport layer 131, a first light absorption layer 132 and a first electron transport layer 133 arranged in sequence along the first direction, the second battery cell 14 includes a second hole transport layer 141, a second light absorption layer 142 and a second electron transport layer 143 arranged in sequence along the first direction; wherein the first electron transport layer 133 and the second hole transport layer 141 are arranged adjacent to and in contact with each other, and at least one of the layers is arranged as an array of columnar nanoparticles, and nanoparticles are distributed on the surface of at least one of the columnar nanoparticles.

[0059] The term "tandem solar cell" in this application refers to a solar cell having a structure of at least two battery cells stacked and arranged along the direction of incident light. The stacking of at least two battery cells can increase the utilization rate of incident sunlight.

[0060] The present application does not particularly limit the number of battery cells included in the stacked solar cell. For example, the number of battery cells included in the stacked solar cell can be 2, 3, 4, etc.

[0061] In the following description, a stacked solar cell including two battery cells (a first battery cell 13 and a second battery cell 14) is taken as an example.

[0062] The "columnar" mentioned in this article can be a columnar shape (such as a nanorod) with a circular or near-circular cross-section (such as an elliptical shape, or an irregular shape that is roughly circular), or a tubular shape (such as a nanotube) with a circular or near-circular cross-section (such as an elliptical ring, or an irregular ring that is roughly circular).

[0063] Further reading Figure 3 , which schematically shows an array of columnar nanoparticles (cylindrical nanoparticles). It should be understood that Figure 3 The columnar nanoparticles 15 shown have the same size, which is merely an illustration. In practice, the size of each columnar nanoparticle in the array may not be exactly the same.

[0064] Mentioning columnar nanoparticles in the present application refers to particles with a size (cross-sectional diameter a, height h) of nanometer scale. In the array, each columnar nanoparticle 15 is arranged longitudinally, i.e., the longitudinal direction of the columnar nanoparticles is substantially parallel to the first direction, and the upper and lower surfaces of the columnar nanoparticles contact the upper and lower layers adjacent to each other. Like this, the upper and lower surfaces of each nanoparticle and the layers adjacent to each other up and down have a larger contact area, thereby helping carriers to transmit along the columnar nanoparticles.

[0065] In the present application, the height h of columnar nanoparticles refers to the size of columnar nanoparticles in the first direction. The cross-sectional diameter a of columnar nanoparticles refers to the diameter of any cross section of the columnar nanoparticles. If the cross section of the columnar nanoparticles is not a regular circle, then the cross-sectional diameter a refers to the length of the longest line segment that the straight line through the geometric center point of the cross section intersects with the cross-sectional edge. If the area of ​​the cross section of the columnar nanoparticles within the scope of its height h changes, then the cross-sectional diameter a refers to the diameter of the cross section with the largest area.

[0066] In some embodiments, the cross-sectional diameter a of the columnar nanoparticles is 10 nm to 50 nm. In a further embodiment, a is 20 nm to 30 nm. Exemplarily, a is 10 nm, 20 nm, 30 nm, 40 nm, 50 nm or a value between any two values within the range, but not limited thereto. By controlling the cross-sectional diameter a of the columnar nanoparticles within the above range, on the one hand, it is beneficial to form an appropriate number of columnar nanoparticles and improve the composite sites; on the other hand, it is easy to prepare and beneficial to improve the stability of the battery. In some embodiments, the height h of the columnar nanoparticles is 10 nm to 30 nm. In a further embodiment, h is 15 nm to 20 nm. Exemplarily, h is 10 nm, 15 nm, 20 nm, 25 nm, 30 nm or a value between any two values within the range, but not limited thereto. By controlling the height h of the columnar nanoparticles within the above range, on the one hand, it is beneficial to increase the number of nanoparticles arranged on the surface of the columnar nanoparticles, thus facilitating appropriate composite sites; on the other hand, it will not cause an increase in resistance.

[0067] In a specific embodiment, the first electron transport layer 133 is arranged as a columnar nanoparticle array. In this embodiment, the material of the first electron transport layer 133 includes at least one of fullerene compounds, TiO2, ZnO, SnO2, and carbon nanotubes. The above materials are beneficial for the first electron transport layer 133 to exert its electron transport advantage while being beneficial for the formation of columnar nanoparticles.

[0068] This application does not particularly limit the electron transport material used when the first electron transport layer 133 is arranged as a layered structure. Exemplarily, the electron transport material includes fullerene compounds (e.g., PCBM, C 60 ), metal oxides (where the metal includes tin, magnesium, cadmium, zinc, etc.), etc.

[0069] In another specific embodiment, the second hole transport layer 141 is arranged as a columnar nanoparticle array. In this embodiment, the material of the second hole transport layer includes at least one of SnO x , NiO x , CuSCN, Cu2O, and CuI, where 1 < x < 2. The above materials are beneficial for the second hole transport layer 141 to exert its hole transport advantage while being beneficial for the formation of columnar nanoparticles.

[0070] This application does not particularly limit the hole transport material used when the second hole transport layer 141 is arranged as a layered structure. For example, the hole transport material includes at least one of inorganic hole transport materials and organic hole transport materials. Exemplarily, the inorganic hole transport material includes at least one of metal oxides and cuprous thiocyanate. Exemplarily, the metal oxides include SnOx , NiO x , Cu2O, where 1 < x < 2. Exemplary organic hole transport materials include: [2-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid, poly(3,4-ethylenedioxythiophene) (PEDOT), poly(styrenesulfonic acid) (PSS), poly(3-hexylthiophene), triphenylamine with a triptycene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-anilino)carbazole-spirobifluorene, polythiophene, etc.

[0071] In other embodiments, in addition to the first electron transport layer 133 and the second hole transport layer 141, Figure 1 and Figure 2 other functional layers may be interposed between the layers shown in the embodiments, such as a passivation layer, a hole blocking layer, an electron blocking layer, etc.

[0072] In the present application, the columnar nanoparticle array can be formed by disposing a mask plate with a specific pattern (e.g., through holes distributed in an array) on the functional layer where the columnar nanoparticle array is to be formed ( Figure 1 and Figure 2 in the embodiments shown, on the first light absorption layer 132 or the second light absorption layer 142). By depositing a corresponding material (electron transport material or hole transport material) in the specific pattern to form a columnar nanoparticle array, and then removing the mask plate to expose the surface of the columnar nanoparticles (sidewalls and the end face away from the functional layer) for subsequent arrangement of nanoparticles on the surface of the columnar nanoparticles. Among them, the deposition method may include: vacuum evaporation method, atomic layer deposition method, chemical vapor deposition method, physical vapor deposition method, etc., and the present application has no special limitation on this. The thickness of the mask plate in the first direction is generally greater than or equal to the height of the columnar nanoparticles. In some embodiments, the mask plate can be a nitrocellulose resin mask plate so that the mask plate can be removed simply by tearing after the columnar nanoparticle array is formed. In some implementation manners, by adjusting the mask plate pattern, a columnar nanoparticle array with a predetermined array arrangement and a predetermined size can be obtained.

[0073] Specifically, taking the arrangement of the first electron transport layer as a columnar nanoparticle array as an example. First, after forming the first light absorption layer, a mask plate with through holes arranged in an array is disposed on the first light absorption layer. Fix the mask plate to keep a certain relative position with the first light absorption layer. Then, by depositing an electron transport material (e.g., SnO2) in the through holes of the mask plate, a columnar nanoparticle array is formed on the first light absorption layer. Then, the mask plate is removed to expose the surface of the columnar nanoparticles.

[0074] Generally speaking, the size of the columnar nanoparticles can be controlled by preparing the mask of the columnar nanoparticle array and the deposition process. In addition, the a and h of the columnar nanoparticles can be tested by disassembling the solar cell using a scanning electron microscope (SEM) method.

[0075] The method for testing the height h of the columnar nanoparticles can include, for example, disassembling a battery packaging component (e.g., photovoltaic glass) to obtain a laminated solar cell. The laminated solar cell is then sectioned along a first direction, and an image of the section is observed and captured using a SEM to determine the height of the columnar nanoparticles. In some implementations, h can be obtained by measuring the heights of multiple columnar nanoparticles and averaging them.

[0076] The method for testing the cross-sectional diameter a of the columnar nanoparticles can include, for example, disassembling a battery packaging component to obtain a laminated solar cell. Removing a functional layer covering the columnar nanoparticle array to expose the top of the columnar nanoparticle array, observing and photographing the exposed top of the columnar nanoparticle array using a SEM, and thereby obtaining the cross-sectional diameter a of the columnar nanoparticles. In some implementations, a can be obtained by measuring the cross-sectional diameters of multiple columnar nanoparticles and averaging them.

[0077] See further Figure 3 , and see Figure 5 ,in Figure 5 Schematic diagram of a columnar nanoparticle array with nanoparticles distributed on the surface.

[0078] In the present application, the spacing (d) between two adjacent columnar nanoparticles refers to the shortest distance between the outer surfaces of two adjacent columnar nanoparticles 15. In some embodiments, the spacing d between two adjacent columnar nanoparticles 15 is less than or equal to 40nm. Optionally, d is 6nm to 20nm. For example, d is 2nm, 6nm, 8nm, 10nm, 12nm, 14nm, 16nm, 18nm, 10nm, 30nm, 40nm or a value between the ranges consisting of any two numerical values, but is not limited thereto. By controlling the spacing d between two adjacent columnar nanoparticles 15 to be within the above-mentioned range, sufficient space can be provided for accommodating nanoparticles 16, while facilitating the arrangement of functional layers (second hole transport layer, second light absorption layer) thereon.

[0079] See also Figure 4 , which is a schematic diagram of a nanoparticle cross-section. The term "nanoparticle" in this application refers to particles with a size (particle diameter) of the nanometer scale. Nanoparticle 16 can be at least one of spherical, approximately spherical, and polyhedral. Exemplarily, nanoparticle 16 is at least one of spherical, oblate, prolate, nanoflower, and nanosheet.

[0080] See also Figure 5 and Figure 6 Nanoparticles 16 are distributed on the surface of each columnar nanoparticle 15, providing recombination sites for the recombination of electrons generated by the first light absorbing layer 132 and holes generated by the second light absorbing layer 142. Compared to traditional tandem solar cells, the tandem solar cell of the present application does not have a layered recombination layer. Instead, the nanoparticles 16 distributed on the surface of the columnar nanoparticles 15 provide recombination sites for electrons and holes. This structure further improves the recombination efficiency, thereby helping to increase the open circuit voltage and thereby increase the photoelectric conversion efficiency.

[0081] In some implementations, adjacent nanoparticles 16 are spaced apart (ie, spaces are left between adjacent nanoparticles 16 ) to further increase the number of recombination sites.

[0082] In some embodiments, the average particle size r of the nanoparticles is 1 nm to 20 nm. Alternatively, r is 2 nm to 10 nm. Exemplarily, the average particle size r of the nanoparticles is 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm or a value between the ranges consisting of any two values, but is not limited thereto. By controlling the average particle size of the nanoparticles within the above range, the aggregation of the nanoparticles can be reduced, which is conducive to increasing the number of recombination sites.

[0083] In some embodiments, the materials used for the nanoparticles 16 include gold, platinum, iron, cobalt, nickel, zinc, manganese, cadmium, silver, copper, indium tin oxide, indium zinc oxide, etc. In some embodiments, the materials used for the nanoparticles 16 include gold, platinum, indium tin oxide, indium zinc oxide, etc. These materials have high electrical conductivity, and the use of nanoparticles 16 containing these materials facilitates the recombination of electrons and holes.

[0084] In some embodiments, the ratio (σ) of the spacing d between two adjacent columnar nanoparticles to the particle size of the nanoparticles is 1.5-3.5, optionally 2.0-3.0. Exemplary, σ is 1.5, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.5 or a value between the ranges formed by any two numerical values, but is not limited thereto. By controlling σ within the above-mentioned range, sufficient space can be provided for accommodating nanoparticles so that the nanoparticles on different columnar nanoparticles do not contact each other, so as to avoid lateral movement of carriers. Simultaneously, the above-mentioned ratio σ also makes the columnar nanoparticle gap appropriate, which is conducive to reducing or avoiding the gap between the material of the functional layer above the columnar nanoparticles 15 from penetrating into the columnar nanoparticles 15.

[0085] In some embodiments, the ratio (ω) of the particle size of the nanoparticles 16 to the cross-sectional diameter of the columnar nanoparticles 15 is 0.1 to 1, and optionally, ω is 0.1 to 0.5. Exemplarily, ω is 0.1, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, 1, or a range consisting of any two values, but is not limited thereto. By controlling ω within the above range, the nanoparticles 16 can achieve a better coverage effect on the surface of the columnar nanoparticles.

[0086] In the present application, nanoparticles can be formed by a chemical reduction reaction method. For example: first, a compound containing nanoparticle elements at a certain mass concentration is prepared as a precursor solution (for example: a 0.01% mass concentration of gold chloride tetrahydrate (HAuCl4·4H2O) aqueous solution). Then, a reducing agent (for example: a 1% mass concentration of trisodium citrate (Na3C6H5O7·3H2O) aqueous solution) is added to the precursor solution, and after reacting for a certain time (for example: 10 minutes) at a certain reaction temperature (for example: 100°C), a solution containing nanoparticles is obtained. By controlling the mass concentration of the compound containing nanoparticle elements in the precursor solution, the reaction temperature and the reaction time, the average particle size of the nanoparticles can be controlled. In the present application, the mass concentration of the solution is the mass ratio of the solute to the solution.

[0087] A solution containing nanoparticles is spin-coated on the surface of the columnar nanoparticles. After annealing (for example, annealing at 100° C. for 5 minutes), the nanoparticles are distributed on the surface of the columnar nanoparticles.

[0088] In some embodiments, the ratio of the total surface area of ​​the nanoparticles to the total surface area of ​​the columnar nanoparticles can be controlled by spin coating nanoparticle solutions of varying mass concentrations. The particle size of the nanoparticles can be determined by preparing a solution containing the nanoparticles, dropping the solution containing the nanoparticles onto a copper mesh, and observing and measuring the average particle size r of the nanoparticles using a transmission electron microscope (TEM).

[0089] Alternatively, the average diameter of the nanoparticles can be determined by disassembling the solar cell and observing it with a TEM. For example, the functional layer covering the columnar nanoparticles can be removed to expose the nanoparticles on the surface of the columnar nanoparticles. The particle sizes of multiple nanoparticles can be measured and the average value calculated can be used as the average particle size of the nanoparticles.

[0090] In some embodiments, the ratio (γ) of the total surface area of ​​the nanoparticles (S1) to the total surface area of ​​the columnar nanoparticles (S2) is 50% to 90%. Exemplarily, γ is 50%, 60%, 70%, 80%, 90%, or a range between any two values, but is not limited thereto. This configuration helps increase the number of recombination sites while reducing or preventing the material of the functional layer above the columnar nanoparticles from penetrating into the gaps between the columnar nanoparticles 15.

[0091] The total number of spin-coated nanoparticles N1 can be obtained by the content of nanoparticles in the solution to which the nanoparticles are attached, the particle size r and the specific gravity of the material, and based on S1=πr 2 *N1, calculate the total surface area S1 of the nanoparticles. And obtain a, h and the total number N2 of columnar nanoparticles through the mask and deposition process used in the method for preparing columnar nanoparticle arrays, based on S2=(π*a*h*+(π(a / 2) 2 )*N2, calculate the total surface area S2 of the columnar nanoparticles, which is the sum of the area of ​​the side and top surfaces of the cylinder. The bottom surface is free of nanoparticles. Finally, obtain the ratio γ between the two.

[0092] The ratio of the total surface area of ​​the nanoparticles to the total surface area of ​​the pillared nanoparticles (γ) can also be measured by the following method:

[0093] First, SEM was used to measure the a and h of the columnar nanoparticles. Based on S2=(π*a*h*+(π(a / 2) 2 )*N2 to calculate the total surface area S2 of the columnar nanoparticles. N2 can be estimated using SEM. For example, count the number of columnar nanoparticles in an SEM image and estimate N2 based on the statistical results and the area ratio of the SEM acquisition area to the area surrounding the array top.

[0094] Then, the average particle size r of the nanoparticles was measured using the TEM method. Based on S1=πr 2 *N1, calculate the total surface area of ​​the nanoparticles, S1. N1 can be estimated using TEM methods. For example, count the number of nanoparticles deposited on the surface of columnar nanoparticles in a TEM image. Then, calculate N1 based on the statistical results and the ratio of the area of ​​the TEM acquisition region to S2.

[0095] Finally, the ratio γ of S1 to S2 is calculated.

[0096] It should be understood that the tandem solar cell of this embodiment may also include other functional layers, such as a hole-blocking layer and an electron-blocking layer. The methods for forming these other functional layers are not particularly limited in this embodiment and may be formed using any conventional method, such as spin coating or vapor deposition. These methods are well known to those skilled in the art and will not be described in detail here. This will be further illustrated by the following examples.

[0097] In one embodiment, see Figure 1 , the stacked solar cell includes an inverted solar cell 100. In this embodiment, the first direction is the same as the incident direction of light, that is, the first electrode 11 first receives the incident light. The material used for the first electrode 11 includes a transparent conductive material. The present application has no special restrictions on the transparent conductive material included in the first electrode 11. Exemplarily, the transparent conductive material is indium tin oxide (ITO), fluorine-doped tin oxide (TCO), antimony-doped tin oxide, indium-doped tungsten oxide, indium-doped zinc oxide, aluminum-doped zinc oxide, boron-doped zinc oxide, etc. The material used for the second electrode 12 includes a conductive material, a conductive material. The present application has no special restrictions on the conductive material included in the second electrode 12. For example, the conductive material can be the above-mentioned transparent conductive material, or it can be an opaque conductive material, such as metals and their alloys, and carbon single-element materials. Exemplarily, metals and their alloys are such as: gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, and tungsten. Exemplarily, carbon single-element materials are such as graphite, graphene, and carbon nanotubes.

[0098] The present application has no particular limitation on the thickness of the first electrode 11 and the second electrode 12 , and the electrode thickness commonly used in the art may be used.

[0099] The first hole transport layer 131 is disposed on the first electrode 11 and includes a hole transport material. The present application does not particularly limit the hole transport material included in the first hole transport layer 131. Specific examples of the hole transport material included in the first hole transport layer 131 are the same as those described above and are not further described here.

[0100] The present application has no particular limitation on the thickness of the first hole transport layer 131 , and the thickness of the hole transport layer conventionally used in the art may be adopted.

[0101] The first light absorbing layer 132 includes a perovskite material. To improve the photoelectric conversion efficiency, the first light absorbing layer 132 includes a perovskite material designed to have a wide band gap. For example, the band gap of the perovskite material included in the first light absorbing layer 132 is 1.6eV-2.3eV. The first light absorbing layer 132 includes a perovskite material, which is well known to those skilled in the art. Exemplary perovskite materials used in the first light absorbing layer 132 include: FA 0.8 Cs 0.2 Pb(I 0.6Br 0.4 )3. FA 0.15 Cs 0.85 Pb(I 0.73 Br 0.27 )3. Cs 0.12 MA 0.05 FA 0.83 Pb(I 0.6 Br 0.4 )3, etc.

[0102] The present application has no particular limitation on the thickness of the first light absorbing layer 132 , and the thickness of the light absorbing layer commonly used in the art can be adopted.

[0103] The first electron transport layer 133 is disposed on the first light absorbing layer 132 and is adjacent to and in contact with the second hole transport layer 141. The first electron transport layer 133 and the second hole transport layer 141 are the same as described above and are not described again.

[0104] The second light absorbing layer 142 is disposed on the second hole transporting layer 141 and includes a light absorbing material.

[0105] In this embodiment, the second light absorbing layer 142 includes a perovskite material. The inverted solar cell in which both the first light absorbing layer 132 and the second light absorbing layer 142 include perovskite materials can be referred to as a full perovskite tandem cell. Perovskite materials have high photoelectric conversion efficiency. Compared with other tandem solar cells, the photoelectric conversion efficiency of the full perovskite tandem cell is further improved. In the full perovskite tandem cell, the band gap of the perovskite material in the first light absorbing layer 132 is wider than the band gap of the perovskite material in the second light absorbing layer 142. For example, the band gap of the perovskite material included in the first light absorbing layer 132 is 1.6eV-2.3eV, the band gap of the perovskite material included in the second light absorbing layer 142 is 1.1eV-1.4eV, and the perovskite material included in the second light absorbing layer 142 is, for example, MA 0.3 FA 0.7 Pb 0.5 Sn 0.5 I3、MAPb 0.85 Sn 0.15 I3、FAPb 0.5 Sn 0.5 I3、FA 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3.

[0106] The present application has no particular limitation on the thickness of the second light absorbing layer 142 , and the thickness of the light absorbing layer conventionally used in the art may be adopted.

[0107] The second electron transport layer 143 includes an electron transport material. The present application does not particularly limit the electron transport material included in the second electron transport layer 143. Specific examples of the electron transport material included in the second electron transport layer 143 are the same as those in the above embodiment and are not repeated here.

[0108] The present application has no particular limitation on the thickness of the second electron transport layer 143 , and the thickness of the electron transport layer conventionally used in the art may be adopted.

[0109] In another embodiment, see Figure 2 The stacked solar cell includes a formal solar cell 200. In this embodiment, the first direction is opposite to the incident direction of light, that is, the second electrode 12 first receives the incident light. The second electrode 12 can be made of the above-mentioned transparent conductive material, and the first electrode 11 can be made of the above-mentioned conductive material.

[0110] and Figure 1 Different from the method shown in the figure, in this embodiment, the second electron transport layer 143 receives the incident light preferentially compared to the second hole transport layer 141, and the first light absorbing layer 132 may include crystalline silicon material, perovskite material, etc. Among them, crystalline silicon material includes: single crystal silicon, heterojunction, etc. The perovskite material used in the first light absorbing layer 132 includes: MA 0.3 FA 0.7 Pb 0.5 Sn 0.5 I3、MAPb 0.85 Sn 0.15 I3、FAPb 0.5 Sn 0.5 I3、FA 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3, etc. The second light absorbing layer 142 includes a perovskite material. For example, the perovskite material used in the second light absorbing layer 142 includes: FA 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3. FA 0.15 Cs 0.85 Pb(I 0.73 Br 0.27 )3. Cs 0.12 MA 0.05 FA 0.83 Pb(I 0.6 Br 0.4 ) 3, etc. A formal solar cell in which the first light absorbing layer 132 includes crystalline silicon material can be called a perovskite-silicon tandem cell.

[0111] According to one embodiment, see Figure 7The structure of the inverted solar cell 300 of this embodiment is shown as an example. In this embodiment, the first battery unit 13 is arranged on the first electrode 11 and includes a first hole transport layer 131, a first light absorption layer 132, and a first electron transport layer 133 arranged in sequence along a first direction (the direction of light incidence). The first electron transport layer 133 is arranged as an array of columnar nanoparticles; the second battery unit 14 is arranged on the first battery unit 13 and includes a second hole transport layer 141, a second light absorption layer 142, and a second electron transport layer 143 arranged in sequence along the first direction, a hole blocking layer 144, and the second electrode 12 is arranged on the hole blocking layer 144.

[0112] The other functional layers are the same as those in the previous embodiment and are not described in detail here. In this embodiment, a hole blocking layer 144 is disposed between the second electron transport layer 143 and the second electrode 12. The hole blocking layer 144 blocks holes to reduce the recombination of electrons and holes.

[0113] The present application has no particular limitation on the hole blocking material included in the hole blocking layer 144. For example, the hole blocking material may be at least one of bathocuproine (BCP), a fullerene compound, and SnOz (1.5≤z≤2).

[0114] The present application has no particular limitation on the thickness of the hole blocking layer 144 , and the thickness of the hole blocking layer conventionally used in the art may be adopted.

[0115] According to one embodiment, see Figure 8 The structure of the inverted solar cell 400 of this embodiment is shown as an example. In this embodiment, the first cell 13 is arranged on the first electrode 11 and includes a first hole transport layer 131, a first light absorption layer 132, and a first electron transport layer 133 arranged in sequence along a first direction (the direction of light incidence). The second cell 14 is arranged on the first cell 13 and includes a second hole transport layer 141, a second light absorption layer 142, a second electron transport layer 143 arranged in sequence along the first direction, a hole blocking layer 144, and the second electrode 12 is arranged on the hole blocking layer 144. The second hole transport layer 141 is arranged as an array of columnar nanoparticles.

[0116] In this embodiment, the other functional layers are the same as those in the above embodiment and are not described again here.

[0117] The present application also provides a photovoltaic module. Typically, the photovoltaic module includes the aforementioned stacked solar cells, a welding ribbon connecting the multiple stacked solar cells, a junction box for current transmission, and a battery packaging component.

[0118] In some embodiments, the battery packaging component includes photovoltaic glass, which covers the laminated solar cells and protects them. Photovoltaic glass also has excellent light transmittance and high hardness, making it adaptable to large temperature swings between day and night and adverse weather conditions.

[0119] In some embodiments, the battery packaging component includes an ethylene-vinyl acetate copolymer (EVA) film layer, which is arranged between the photovoltaic glass and the laminated solar cell to bond the photovoltaic glass and the solar cell.

[0120] In some embodiments, the cell packaging component includes a photovoltaic backsheet, which also serves to protect the laminated solar cells.

[0121] Optionally, the material of the photovoltaic backsheet can be a polyvinyl fluoride composite film or a thermoplastic elastic material. The material of the photovoltaic backsheet has the properties of insulation, waterproofness, and aging resistance.

[0122] In some embodiments, the battery packaging component includes a solar aluminum frame, which is made of aluminum alloy and has the characteristics of high strength and good corrosion resistance, and can support and protect the solar cell.

[0123] An embodiment of the present application also provides a power generation device, including the stacked solar cell provided in the above embodiment.

[0124] An embodiment of the present application further provides an electrical device, comprising the stacked solar cell provided in the above embodiment.

[0125] In some embodiments, the electrical device may also be a lighting device, an energy storage device, etc., and the embodiments of the present application include but are not limited to the above. For example, the electrical device may be a solar water heater, a solar street light, a solar photovoltaic generator, etc.

[0126] Example

[0127] The following examples are provided for illustrative purposes only and are intended to illustrate the present invention and are not to be construed as limiting the present invention. Unless otherwise specified, all reagents used were commercially available and all equipment used was conventional.

[0128] Example 1

[0129] Preparation of tandem solar cells (all perovskite tandem cells or inverted solar cells):

[0130] (1) Providing a first electrode: Take a TCO conductive glass (FTO) with a specification of 2.0*2.0 cm, remove 0.35 cm of FTO at each end by laser etching, and expose the glass substrate; ultrasonically clean the etched FTO with a cleaning solution, deionized water, and ethanol in sequence; blow the solvent out of the FTO under a nitrogen gun and place it in a UV ozone machine for further cleaning.

[0131] (2) Providing a first hole transport layer: On the FTO treated with UV ozone, a 15 mg / mL aqueous solution of nickel oxide nanoparticles was spin-coated at a rate of 2000 rpm / s in a glove box, and then thermally annealed at 100°C for 10 min to form a first hole transport layer with a thickness of 30 nm.

[0132] (3) Providing a first light absorption layer: Weigh 1659 mg of lead iodide, 880 mg of lead bromide, 240 mg of bromoformamidine, 495 mg of iodoformamidine, 187 mg of cesium iodide, and 102 mg of cesium bromide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 4:1). Stir for 1 hour, filter with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution, take 100 μL of the perovskite precursor solution, spin-coat the perovskite precursor solution on the first hole transport layer at 5000 rpm, then place it in a vacuum flash evaporation device for 30 seconds, transfer it to a 100°C hot plate for annealing for 10 minutes, and form a first light absorption layer (FA) with a thickness of 500 nm. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3).

[0133] (4) Providing a first electron transport layer: A nitrocellulose resin mask with an array of through-holes (20 nm in diameter) is used to cover the surface of the first light absorbing layer. Atomic layer deposition is performed within the through-holes of the mask to form an array of SnO2 nanorods (columnar nanoparticles) on the first light absorbing layer, serving as the first electron transport layer. The mask is then removed, exposing the surface of the SnO2 nanorods (the end faces and side faces facing away from the first light absorbing layer).

[0134] The cross-sectional diameter (a) of the obtained SnO2 nanorods is 20 nm, the height (h) is 20 nm, and the distance (d) between two adjacent SnO2 nanorods is 8 nm.

[0135] (5) Providing a composite layer: First, prepare a 0.01% mass concentration of gold chloride tetrahydrate (HAuCl4·4H2O) aqueous solution and a 1% mass concentration of trisodium citrate (Na3C6H5O7·3H2O) aqueous solution.

[0136] Then, 0.5 mL of trisodium citrate solution was added to 50 mL of HAuCl4 solution at 100°C, and the reaction was continued by stirring for 10 minutes. The mixture was naturally cooled to room temperature to obtain an Au nanoparticle solution.

[0137] The average particle size (r) of the obtained Au nanoparticles was 4 nm. The mass concentration of the Au nanoparticles in the Au nanoparticle solution was about 0.005%.

[0138] The Au nanoparticle solution was spin-coated on the surface of the SnO2 nanorods at a spin-coating speed of 2000 rpm, an acceleration of 1000 rpm / s, and a spin-coating time of 20 s, and then annealed at 100°C for 10 min.

[0139] Among them, the ratio of the average particle size (r) of Au nanoparticles to the cross-sectional diameter (a) of SnO2 nanorods (ω=r / a) is 0.2; the ratio of the distance (d) between two adjacent SnO2 nanorods to the average particle size (r) of Au nanoparticles (σ=d / r) is 2.

[0140] (6) Providing a second hole transport layer: A mixed solution of poly (3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfone (PSS) (purchased from Heraeus, Germany) was spin-coated on the above composite layer at a spin coating speed of 3000 rpm for 20 s, and then transferred to a hot plate for annealing at 100 ° C for 15 min to form a second hole transport layer with a thickness of 15 nm.

[0141] The distance between the top of the SnO2 nanorod (the end away from the first electrode) and the top of the second hole transport layer can be approximately considered as the thickness of the second hole transport layer.

[0142] (7) Providing a second light absorbing layer: adding 2 mg of iodomethane, 85 mg of iodomethylamine, 4 mg of lead iodide, and 335 mg of stannous iodide to 1 mL of a mixed solvent of DMF and DMSO (the volume ratio of DMF to DMSO is 2:1), stirring at a speed of 600 rpm on a magnetic stirrer for 2 h, filtering to obtain a perovskite precursor solution; spin-coating 100 μL of the above perovskite precursor solution onto the above second hole transport layer, first at a spin-coating speed of 1 000 rpm, acceleration 200 rpm / s spin coating for 10s, then spin coating at a spin coating speed of 3000 rpm, acceleration 1000 rpm / s for 20s, then add 500 μL of ethyl acetate to the spin-coated perovskite precursor solution, then spin-coat the above perovskite precursor solution again, the spin coating speed is 4000 rpm, the spin coating time is 20s, and then transfer to a hot stage for annealing at 100 ° C for 10 minutes to form a second light absorption layer (FA) with a thickness of 1 μm 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3).

[0143] (8) Providing a second electron transport layer: spin-coating a 15 mg / mL fullerene compound (PCBM) chlorobenzene solution on the second light absorbing layer to form a second electron transport layer with a thickness of 10 nm.

[0144] (9) Providing a hole blocking layer: Bathocuproin (BCP) with a thickness of 10 nm was evaporated on the second electron transport layer as a hole blocking layer.

[0145] (10) Providing a second electrode: On the hole blocking layer, metal copper is evaporated to a thickness of 100 nm as the second electrode.

[0146] Test of the ratio of the total surface area of ​​Au nanoparticles to the total surface area of ​​SnO2 nanorods (γ):

[0147] Based on S2=(π*a*h*+(π(a / 2) 2 )*N2, calculate the total surface area S2 of SnO2 nanorods, where N2 is the number of columnar nanoparticles and N2 is equal to the number of through holes contained in the mask.

[0148] Then, the Au nanoparticle solution obtained in step (5) was dropped onto a copper mesh, and the average particle size r of the Au nanoparticles was measured using a TEM method.

[0149] Then, the structure obtained in step (5) is directed away from the first electrode at one end toward the TEM and toward the electron beam, and the TEM is started to acquire an image. The number of Au nanoparticles deposited on the surface of the SnO2 nanorods in the image is counted, and then N1 is calculated based on the statistical results and the ratio of the area of ​​the TEM acquisition area to S2.

[0150] Then, based on S1=πr 2 *N1, calculate the total surface area S1 of the nanoparticles.

[0151] Finally, the ratio of S1 to S2 is calculated to be γ=75%.

[0152] Tests of open circuit voltage (Voc) and photoelectric conversion efficiency (PCE) of stacked solar cells:

[0153] Under atmospheric conditions, an AM1.5G standard light source was used as a sunlight simulating light source, and a four-channel digital source meter (Keithley 2440) was used to measure the volt-ampere characteristic curve of the battery under illumination. Based on the volt-ampere characteristic curve, the open-circuit voltage, short-circuit current density (Jsc), and passivation factor (FF) of the stacked solar cell were obtained.

[0154] The photoelectric conversion efficiency (PCE) of the tandem solar cell is calculated using the following formula;

[0155] PCE=Pout / Popt

[0156] =Voc*Jsc*(Vmpp*Jmpp) / (Voc*Jsc)

[0157] =Voc*Jsc*FF.

[0158] Pout, Popt, Vmpp, and Jmpp represent the battery operating output power, incident light power, battery maximum power point voltage, and maximum power point current, respectively.

[0159] Example 2

[0160] The full perovskite stacked cell was prepared according to the method of Example 1, except that:

[0161] The step of providing the first electron transport layer includes: using an atomic deposition method to prepare a SnO2 film with a thickness of 20 nm as the first electron transport layer on the above-mentioned first light absorption layer.

[0162] The step of providing the second hole transport layer includes: using a mask having an array of through holes to cover the surface of the first electron transport layer, performing atomic layer deposition in the through holes of the mask to form SnO on the first electron transport layer. 1.5 The nanorod (columnar nanoparticle) array serves as the second hole transport layer, and the mask is then removed.

[0163] The obtained SnO 1.5 The cross-sectional diameter (a) of the nanorod is 20 nm, the height (h) is 20 nm, and the two adjacent SnO 1.5 The spacing (d) between the nanorods is 8 nm.

[0164] Au metal nanoparticles deposited on SnO 1.5 The surface of the nanorods.

[0165] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 1-2.

[0166] Comparative Example 1

[0167] The full perovskite stacked cell was prepared according to the method of Example 1, except that:

[0168] The step of providing the composite layer includes: evaporating an Au film layer with a thickness of 4 nm on the first electron transport layer as the composite layer.

[0169] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 1-2.

[0170] Comparative Example 2

[0171] The full perovskite stacked cell was prepared according to the method of Example 1, except that:

[0172] The step of providing the first electron transport layer includes: evaporating a SnO2 film with a thickness of 20 nm on the first light absorbing layer as the first electron transport layer.

[0173] The step of providing the composite layer includes: evaporating an Au film layer with a thickness of 4 nm on the first electron transport layer as the composite layer.

[0174] The step of providing the second hole transport layer comprises: preparing SnO on the first electron transport layer by atomic deposition method; 1.5 The film layer serves as the second hole transport layer. Performance tests were conducted in the same manner as in Example 1. The test results are shown in Table 1-2.

[0175] Table 1-1

[0176]

[0177] Table 1-2

[0178] Serial number Voc(V) PCE (%) Example 1 2.053 27.02 Example 2 1.998 26.56 Comparative Example 1 1.902 25.46 Comparative Example 2 1.832 25.32

[0179] It can be seen from Table 1-1 and Table 1-2 that compared with the all-perovskite tandem cells prepared in Comparative Example 1 or 2, the open circuit voltage and photoelectric conversion efficiency of the all-perovskite tandem cells prepared in Example 1 or 2 are improved.

[0180] Example 3

[0181] Preparation of tandem solar cells (perovskite-crystalline silicon tandem cells or formal solar cells):

[0182] (1) Providing crystalline silicon cells: A textured n-type single crystal silicon wafer (c-Si) is cleaned with hydrogen peroxide solution, hydrofluoric acid, and hydrochloric acid in sequence as the first light absorption layer. On one side, intrinsic amorphous silicon (ia-Si:H) is deposited by plasma enhanced chemical vapor deposition (PECVD) to passivate the c-Si surface. A p-doped a-Si:H layer (as the first hole transport layer) is then deposited by PECVD on the ia-Si:H surface with a thickness of approximately 10 nm. Then, a 1.5 nm thick SiO2 layer is grown on the other side by wet chemical methods (oxidation reaction in 68% mass concentration concentrated nitric acid for 30 minutes at 90°C) as a hole blocking layer. On its surface, an n-doped a-Si:H layer (the first electron transport layer) is deposited by PECVD with a thickness of approximately 5 nm. On one side of the p-type layer, 80 nm of ITO is deposited by magnetron sputtering as a transparent electrode (the first electrode). Then, an Ag gate is screen-printed on the p-type side as a back electrode.

[0183] (2) Providing a second hole transport layer: Using a mask of nitrocellulose resin with array through holes (aperture size of 20 nm) to cover the n-type side, and then performing atomic layer deposition to prepare SnO 1.5The array of nanorods serves as the second hole transport layer.

[0184] Among them, SnO 1.5 The cross-sectional diameter (a) of the nanorod is 20 nm, the height (h) is 20 nm, and the two adjacent SnO 1.5 The spacing (d) between the nanorods is 10 nm.

[0185] (3) Providing composite layer: In SnO 1.5 The surface of the nanorods was spin-coated with ITO nanoparticle solution at a spin coating speed of 1000 rpm / s, an acceleration of 2000 rpm and a spin coating time of 20 s. The solution was annealed at 100 °C for 10 min. The ITO nanoparticles were distributed on the SnO 1.5 Nanorod surface. The total surface area of ​​ITO nanoparticles is similar to that of SnO 1.5 The ratio (γ) of the total surface area of ​​the nanorods was 75%.

[0186] The ITO nanoparticle solution (manufacturer: Sigma-ALDRICH) has an average particle size of about 5 nm and a mass concentration of about 20%.

[0187] (4) Providing a second light absorption layer: Weigh 1659 mg of lead iodide, 880 mg of lead bromide, 240 mg of bromoformamidine, 495 mg of iodoformamidine, 187 mg of cesium iodide, and 102 mg of cesium bromide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 4:1). Stir for 1 hour, filter with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution, take 100 μL of the perovskite precursor solution, and spin-coat the perovskite precursor solution on the second hole transport layer at a rotation speed of 5000 rpm. Then, place the obtained solution in a vacuum flash evaporation device for 30 seconds, transfer it to a hot plate at 100°C for annealing for 10 minutes, and form a second light absorption layer (FA) with a thickness of 500 nm. 0.8 Cs 0.2 Pb(I0.6Br 0.4 )3).

[0188] (5) Provide a second electron transport layer: On the second light absorbing layer, evaporate C with a thickness of 20 nm. 60 as the second electron transport layer.

[0189] (6) Providing a hole blocking layer: Using atomic layer deposition, SnO2 with a thickness of 20 nm is deposited on the second electron transport layer as a hole blocking layer.

[0190] (7) Providing a second electrode: Depositing a 100 nm thick metal ITO as the second electrode on the hole blocking layer by physical vapor deposition (PVD).

[0191] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 2.

[0192] Comparative Example 3

[0193] A perovskite-crystalline silicon tandem cell was prepared according to the method of Example 3, except that:

[0194] The step of providing the composite layer includes: evaporating an ITO film layer with a thickness of 5 nm on the second hole transport layer as the composite layer.

[0195] The performance test was carried out in the same manner as in Example 3. The test results are shown in Table 2.

[0196] Table 2

[0197]

[0198] It can be seen from the data in Table 2 that compared with the perovskite-crystalline silicon tandem cell prepared in Comparative Example 3, the composite layer in the perovskite-crystalline silicon tandem cell prepared in Example 3 is distributed on the surface of the columnar nanoparticles in the form of nanoparticles, and the open circuit voltage and photoelectric conversion efficiency of the perovskite-crystalline silicon tandem cell are improved.

[0199] Examples 4-7

[0200] The full perovskite stacked cells of Examples 4-7 were prepared according to the method of Example 1, except that the material of the nanoparticles was adjusted as shown in Table 3.

[0201] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 3.

[0202] Table 3

[0203] Serial number Nanoparticle materials Voc(V) PCE (%) Example 1 Gold (Au) 2.053 27.02 Example 4 platinum 2.023 26.68 Example 5 Indium Tin Oxide 2.015 25.92 Example 6 Indium zinc oxide 2.020 26.72 Example 7 Gold-platinum alloy 2.049 26.89

[0204] The data in Table 3 show that the open circuit voltage and photoelectric conversion efficiency of the all-perovskite tandem cells prepared in Examples 4-7 are improved compared to the all-perovskite tandem cells prepared in Comparative Examples 1 and 2. In particular, when the nanoparticle material is selected from Au or a gold-platinum alloy, the open circuit voltage and photoelectric conversion efficiency of the all-perovskite tandem cells can be further improved.

[0205] Examples 8-10

[0206] The full perovskite stacked cells of Examples 8-10 were prepared according to the method of Example 1, except that:

[0207] As shown in Table 4, the concentration of HAuCl4 was adjusted to control the mass concentration of Au nanoparticles, thereby adjusting the ratio (γ) of the total surface area of ​​Au nanoparticles to the total surface area of ​​SnO2 nanorods.

[0208] The γ of Examples 8-10 was tested in the same manner as Example 1. The test results are shown in Table 4.

[0209] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 4.

[0210] Table 4

[0211]

[0212] The data in Table 4 show that the open circuit voltage and photoelectric conversion efficiency of the all-perovskite tandem cells prepared in Examples 8-10 are improved compared to the all-perovskite tandem cells prepared in Comparative Examples 1 and 2. In particular, a γ of 50%-90% can further improve the open circuit voltage and photoelectric conversion efficiency of the all-perovskite tandem cells.

[0213] Examples 11-14

[0214] The full perovskite stack cells of Examples 11-14 were prepared according to the method of Example 1, except that: as shown in Table 5, the reaction time and reaction temperature for forming Au nanoparticles were adjusted so that the average particle size r of the Au nanoparticles was as shown in Table 5.

[0215] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 5.

[0216] Table 5

[0217]

[0218] It can be seen from the data in Table 5 that the average particle size of Au nanoparticles in the range of 1nm-20nm can improve the open circuit voltage and photoelectric conversion efficiency of all-perovskite stacked cells.

[0219] Examples 15-21

[0220] The full perovskite stack cells of Examples 15-21 were prepared according to the method of Example 1, except that: as shown in Table 6, the aperture of the mask and the time of atomic deposition were adjusted so that a and h of the SnO2 nanorods were as shown in Table 6.

[0221] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 6.

[0222] Table 6

[0223]

[0224]

[0225] The data in the table show that controlling ω between 0.1 and 0.4 can further improve the open-circuit voltage and photoelectric conversion efficiency of all-perovskite tandem cells. Controlling h between 10 nm and 30 nm can further improve the open-circuit voltage and photoelectric conversion efficiency of all-perovskite tandem cells. Controlling a between 10 nm and 35 nm can further improve the open-circuit voltage and photoelectric conversion efficiency of all-perovskite tandem cells.

[0226] Examples 24 and 25

[0227] The full perovskite stack cells of Examples 24 and 25 were prepared according to the method of Example 1, with the difference that: as shown in Table 7, the spacing between two adjacent through holes in the mask was adjusted so that the spacing (d) between two adjacent SnO2 nanorods was as shown in Table 7.

[0228] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 7.

[0229] Table 7

[0230] Serial number d(nm) σ Voc(V) PCE (%) Example 1 8 2 2.053 27.02 Example 24 6 1.5 2.001 25.98 Example 25 14 3.5 2.021 26.36

[0231] It can be seen from the data in Table 7 that compared with the all-perovskite tandem cells prepared in Comparative Examples 1 and 2, the open circuit voltage and photoelectric conversion efficiency of the all-perovskite tandem cells prepared with σ in the range of 1.5-3.5 are improved.

[0232] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A stacked solar cell, characterized in that: The stacked solar cell comprises a first electrode, at least two battery cells, and a second electrode sequentially stacked along a first direction, wherein the at least two battery cells comprise a first battery cell and a second battery cell, wherein the first battery cell comprises a first light absorption layer and a first electron transport layer sequentially arranged along the first direction, and the second battery cell comprises a second hole transport layer and a second light absorption layer sequentially arranged along the first direction; The first electron transport layer and the second hole transport layer are arranged adjacent to and in contact with each other, and at least one of the layers is arranged as an array of columnar nanoparticles, with nanoparticles distributed on the surface of the columnar nanoparticles.

2. The tandem solar cell according to claim 1, wherein The material of the nanoparticles includes at least one of gold, platinum, indium tin oxide, indium zinc oxide, iron, cobalt, nickel, zinc, manganese, cadmium, silver, and copper.

3. The tandem solar cell according to claim 1 or 2, characterized in that: The ratio of the total surface area of ​​the nanoparticles to the total surface area of ​​the pillared nanoparticles is 50% to 90%.

4. The tandem solar cell according to any one of claims 1 to 3, characterized in that The average particle size of the nanoparticles is 1 nm to 20 nm.

5. The tandem solar cell according to claim 4, characterized in that: The average particle size of the nanoparticles is 2 nm to 10 nm.

6. The tandem solar cell according to any one of claims 1 to 5, characterized in that: The ratio of the particle size of the nanoparticles to the cross-sectional diameter of the columnar nanoparticles is 0.1 to 1.

7. The tandem solar cell according to claim 6, characterized in that: The ratio of the particle size of the nanoparticles to the cross-sectional diameter of the columnar nanoparticles is 0.1 to 0.

5.

8. The tandem solar cell according to any one of claims 1 to 7, characterized in that: The ratio of the distance between two adjacent columnar nanoparticles to the particle size of the nanoparticles is 1.5 to 3.

5.

9. The tandem solar cell according to any one of claims 1 to 8, characterized in that: The first electron transport layer is arranged as an array composed of the columnar nanoparticles, and the material used in the first electron transport layer includes at least one of fullerene compounds, TiO2, ZnO, SnO2, and carbon nanotubes.

10. The tandem solar cell according to any one of claims 1 to 8, characterized in that: The second hole transport layer is arranged as an array of columnar nanoparticles, and the material used in the second hole transport layer includes SnO x 、NiO x , CuSCN, Cu2O, CuI, wherein 1 <x<2。 11. The tandem solar cell according to any one of claims 1 to 10, characterized in that: The cross-sectional diameter of the columnar nanoparticles is 10 nm to 50 nm, and the height of the columnar nanoparticles in the first direction is 10 nm to 30 nm.

12. The tandem solar cell according to any one of claims 1 to 11, characterized in that: The first direction is the same as the incident direction of light.

13. The tandem solar cell according to claim 12, characterized in that: The first light absorbing layer and the second light absorbing layer each include a perovskite material.

14. The tandem solar cell according to any one of claims 1 to 11, characterized in that: The first direction is opposite to the incident direction of light.

15. The tandem solar cell according to any one of claims 1 to 11, characterized in that: The second light absorbing layer includes a perovskite material, and the first light absorbing layer includes a crystalline silicon material.

16. A photovoltaic module, characterized in that: The photovoltaic module comprises the tandem solar cell according to any one of claims 1 to 15.

17. A power generation device, characterized in that: The power generation device comprises the tandem solar cell according to any one of claims 1 to 15.

18. An electrical device, characterized in that: The electric device comprises the tandem solar cell according to any one of claims 1 to 15.

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