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

Abstract

Provided in the present disclosure are a laminated solar cell, a photovoltaic module and an electric device. The laminated solar cell comprises a first electrode and a second electrode, at least two cell units arranged between the first electrode and the second electrode, and a composite layer, wherein the at least two cell units include a first cell unit and a second cell unit, which are sequentially arranged in a first direction, the composite layer is arranged between the first cell unit and the second cell unit, and the first direction is an incident direction of light; the second cell unit comprises a second hole transport layer, a second light absorption layer and a second electron transport layer, which are sequentially arranged in the first direction; and the second cell unit further comprises an electron barrier layer arranged between the second hole transport layer and the second light absorption layer.

Description

Tandem solar cells, photovoltaic modules, power generation devices and power consumption devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on and claims the priority of Chinese patent application with application number 202420343282.4, application date February 23, 2024, and invention name “Stacked solar cells, photovoltaic modules, power generation devices and power-using devices”. The entire content of the Chinese patent application is hereby incorporated into this disclosure as a reference. Technical Field

[0003] The present disclosure 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

[0004] 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.

[0005] 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.

[0006] Tandem solar cells, particularly all-perovskite tandem solar cells, typically have a wide bandgap on the bottom cell and a narrow bandgap on the top cell. Limited by the bandgap of the light-absorbing layer in the top cell, the hole transport layer in the top cell primarily uses organic hole transport materials, resulting in a low thickness. This thickness limitation weakens the hole transport layer's ability to block electrons, leading to non-radiative recombination of holes and electrons in the top cell, limiting the improvement of the tandem solar cell's photoelectric conversion efficiency. Summary of the Invention

[0007] The present disclosure is made in response to the aforementioned challenges and aims to provide a tandem solar cell, photovoltaic module, and photovoltaic device. By disposing an electron blocking layer and a second hole transport layer in the second cell unit, the tandem solar cell achieves multi-layer electron blocking in the second cell unit, enhancing the electron blocking effect and reducing non-radiative recombination of electrons and holes, thereby improving the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0008] In order to achieve the above-mentioned objectives, the present disclosure provides a tandem solar cell, which includes a first electrode and a second electrode; at least two battery cells arranged between the first electrode and the second electrode, and a composite layer; the at least two battery cells include a first battery cell and a second battery cell arranged in sequence along a first direction, and the composite layer is arranged between the first battery cell and the second battery cell, wherein the first direction is the incident direction of light; wherein the second battery cell includes a second hole transport layer, a second light absorption layer, and a second electron transport layer arranged in sequence along the first direction; the second battery cell further includes an electron blocking layer arranged between the second hole transport layer and the second light absorption layer. In the present disclosure, by arranging an electron blocking layer on the basis of the second hole transport layer, multi-layer blocking of electrons in the second battery cell can be achieved, thereby enhancing the electron blocking effect, thereby reducing the non-radiative recombination of electrons and holes, and thus improving the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0009] In some embodiments, the thickness of the electron blocking layer is 1 nm to 25 nm, and optionally 1 nm to 20 nm. By controlling the thickness of the electron blocking layer within the above range, the electron blocking layer can produce less light absorption while exerting its electron blocking effect, and is also conducive to reducing the electron blocking layer's absorption of sunlight.

[0010] In some embodiments, the thickness of the electron blocking layer is 5 nm to 20 nm. By controlling the thickness of the electron blocking layer within the above range, the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell can be further improved.

[0011] In some embodiments, the electron blocking layer is arranged as a film structure or as islands of nanoparticles. Arranging the electron blocking layer as a film structure can further block the transmission of electrons; arranging the electron blocking layer as islands of nanoparticles can reduce the lateral transmission of holes, thereby improving the utilization rate of holes.

[0012] In some embodiments, the average particle size of the nanoparticles is 1 nm to 30 nm. By controlling the average particle size of the nanoparticles within this range, the aggregation of the nanoparticles can be reduced, which helps further reduce the lateral transport of holes. Furthermore, the average particle size of the nanoparticles is 1 nm to 20 nm, and further optionally 5 nm to 20 nm. This can further reduce the aggregation of the nanoparticles and help reduce the lateral transport of holes.

[0013] In some embodiments, the thickness of the second hole transport layer is 5 nm to 10 nm. By arranging the electron blocking layer and the second hole transport layer, a multi-layered electron barrier can be achieved in the second battery cell. Even if the thickness of the second hole transport layer is within the above range, a strong electron barrier can still be generated in the second battery cell.

[0014] In some embodiments, the first cell is disposed on the first electrode and includes a first hole transport layer, a first light absorbing layer, a first hole blocking layer, a first electron transport layer, and a second hole blocking layer sequentially arranged along a first direction. The arrangement of the first and second hole blocking layers enables multi-layer hole blocking in the first cell, enhancing the hole blocking effect and further reducing non-radiative recombination of holes and electrons, thereby improving the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0015] In some embodiments, the second battery cell further includes a third hole blocking layer disposed between the second light absorbing layer and the second electron transporting layer. The third hole blocking layer blocks holes, thereby further reducing non-radiative recombination of electrons and holes.

[0016] In some embodiments, the second cell further includes a fourth hole blocking layer disposed between the second electron transport layer and the second electrode. By arranging the first, second, third, and / or fourth hole blocking layers, multi-layer hole blocking can be achieved, enhancing the hole blocking effect and further improving the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0017] In some embodiments, the resistivity of the electron blocking layer is greater than or equal to 10 12 Ω·m, can be selected to be greater than or equal to 10 12 Ω·m and less than or equal to 10 18 The electron blocking layer has a strong electron blocking effect.

[0018] In some embodiments, the material of the electron blocking layer includes at least one of an inorganic electron blocking material and an organic electron blocking material.

[0019] In some embodiments, the material of the electron blocking layer includes at least one of an inorganic oxide, an inorganic nitride, an inorganic carbide, an inorganic silicide, an inorganic sulfide, and a carbon material. Selecting at least one of an inorganic oxide, an inorganic nitride, an inorganic carbide, an inorganic silicide, an inorganic sulfide, and a carbon material as the electron blocking layer material can enhance the electron blocking effect and thereby reduce non-radiative recombination of electrons and holes.

[0020] In some embodiments, the tandem solar cell satisfies one or more of the following conditions:

[0021] (1) Inorganic oxides include one or more of antimony oxide, aluminum oxide, cobalt oxide, boron oxide, bismuth oxide, chromium oxide, copper oxide, magnesium oxide, molybdenum oxide, silicon dioxide, vanadium oxide, and zirconium oxide;

[0022] (2) Inorganic nitrides include one or more of aluminum nitride, aluminum nitride, boron nitride, calcium nitride, chromium nitride, europium nitride, magnesium nitride, silicon nitride, titanium nitride, vanadium nitride, zirconium nitride, and gallium nitride;

[0023] (3) Inorganic carbides include one or more of aluminum carbide, boron carbide, chromium carbide, molybdenum carbide, silicon carbide, titanium carbide, vanadium carbide, tungsten carbide, and zirconium carbide;

[0024] (4) Inorganic silicides include one or more of cobalt silicide, magnesium silicide, molybdenum silicide, niobium silicide, titanium silicide, tungsten silicide, and zirconium silicide;

[0025] (5) Inorganic sulfides include one or more of aluminum sulfide, antimony sulfide, bismuth sulfide, barium sulfide, boron sulfide, calcium sulfide, chromium sulfide, cobalt sulfide, europium sulfide, gallium sulfide, magnesium sulfide, molybdenum sulfide, silicon disulfide, tungsten sulfide, vanadium sulfide, and zirconium sulfide;

[0026] (6) The organic electron blocking material includes one or more of diphenylaminocarbazole and methyltriphenylamine carboxylic acid.

[0027] In some embodiments, the band gap of the second light absorbing layer is narrower than the band gap of the first light absorbing layer.

[0028] In some embodiments, the tandem solar cell satisfies one or more of the following conditions:

[0029] (1) The first light absorbing layer includes a perovskite material;

[0030] (2) The band gap of the first light absorbing layer is 1.6eV-2.3eV;

[0031] (3) the second light absorbing layer comprises a perovskite material;

[0032] (4) The band gap of the second light absorbing layer is 1.1 eV to 1.4 eV.

[0033] The first light absorbing layer has a band gap of 1.6eV-2.3eV, which, as a wide band gap cell unit, helps absorb short wavelengths of light. The second light absorbing layer has a band gap of 1.1eV to 1.4eV, which, as a narrow band gap cell unit, helps absorb long wavelengths of light. Together, they can increase the spectral width of light that can be absorbed by the tandem solar cell and improve the photoelectric conversion efficiency of the tandem solar cell. The first light absorbing layer and / or the second light absorbing layer include a perovskite material. Compared to other tandem solar cells, this tandem solar cell has a further improved photoelectric conversion efficiency and is less expensive.

[0034] A second aspect of the present disclosure provides a photovoltaic module, which includes the stacked solar cell provided by the first aspect.

[0035] A third aspect of the present disclosure provides a power generation device, which includes the stacked solar cell provided by the first aspect.

[0036] A fourth aspect of the present disclosure provides an electrical device, comprising the stacked solar cell provided in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is a schematic structural diagram of a stacked solar cell according to an embodiment of the present disclosure.

[0038] FIG2 is a schematic structural diagram of a stacked solar cell according to an embodiment of the present disclosure.

[0039] FIG3 is a schematic structural diagram of a stacked solar cell according to an embodiment of the present disclosure.

[0040] FIG4 is a schematic structural diagram of a stacked solar cell according to an embodiment of the present disclosure.

[0041] Explanation of the figure marks: 10, 100, 200, 300 stacked solar cell; 11 first electrode; 12 second electrode; 13 first battery unit; 131 first hole transport layer; 132 first light absorption layer; 133 first hole blocking layer; 134 first electron transport layer; 135 second hole blocking layer; 14 second battery unit; 141 second hole transport layer; 142 second light absorption layer; 143 second electron transport layer; 144 electron blocking layer; 145 third hole blocking layer; 146 fourth hole blocking layer; 15 composite layer. DETAILED DESCRIPTION

[0042] Below, with appropriate reference to the accompanying drawings, a detailed description of the embodiments of the laminated solar cell, photovoltaic module, power generation device, and power consumption device disclosed herein is specifically disclosed. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical 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 disclosure and are not intended to limit the subject matter described in the claims.

[0043] " scope " disclosed in the present disclosure 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 selected lower limit and upper limit define the boundary of special scope.The scope that this mode limits can be to include end value or not include end value, and can be combined arbitrarily, and promptly any lower limit can form a scope with any upper limit combination.For example, if the scope of 60-120 and 80-110 is listed for specific parameter, 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 listed, and if the maximum range value 3,4 and 5 listed, then the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.In the present disclosure, unless otherwise specified, numerical range " ab " represents the abbreviation of any real number combination between a and b, and 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.

[0044] Unless otherwise specified, all embodiments and optional embodiments of the present disclosure can be combined with each other to form new technical solutions.

[0045] Unless otherwise specified, all technical features and optional technical features disclosed herein can be combined with each other to form a new technical solution.

[0046] Unless otherwise specified, all steps of the present disclosure may be performed sequentially or randomly, preferably sequentially. For example, a method comprising steps (a) and (b) indicates that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, a method further comprising step (c) indicates that step (c) may be added to the method in any order, for example, the method may comprise steps (a), (b), and (c), or may comprise steps (a), (c), and (b), or may comprise steps (c), (a), and (b), etc.

[0047] Unless otherwise specified, the terms used in the present disclosure have the common meanings that are generally understood by those skilled in the art.

[0048] Unless otherwise specified, the numerical values ​​of the parameters mentioned in the present disclosure 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 the present disclosure.

[0049] As used herein, the term "layer" refers to any substantially layered structure. A layer may have a thickness that varies over the extent of the layer. 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.

[0050] If not otherwise specified, reference in the present disclosure to a layer being on 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 are other layers (such as a third layer) interposed between the first and second layers.

[0051] The term "perovskite" as used in this disclosure refers to a material having a three-dimensional crystal structure related to the three-dimensional crystal structure of CaTiO3, or a layer material including 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 comprising a layer of perovskite material are well known. When receiving sunlight, 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 disclosure refers to 3D perovskite materials.

[0052] The general chemical formula of perovskite materials can be expressed as ABX3 or A2CDX6. Here, the A ion is a monovalent cation, the B ion is a divalent metal cation, the C ion is a monovalent metal cation, the D ion is a trivalent metal cation, and the X ion is a monovalent anion. When the perovskite includes more than one A cation, the different A cations can 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 can 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 can be distributed in an orderly or disordered manner on the X site.

[0053] Optionally, the A ion is a monovalent cation with a larger radius, including at least one of an organic cation and a metal cation. More preferably, the organic cation includes an organic amine ion, a carboxamidino group (HC(NH2)2 + , FA + ) and at least one of imidazole; More optionally, the metal cation includes Li + 、Sodium ion (Na + ), potassium ion (K + ), rubidium ions (Rb + ), cesium ions (Cs + ) at least one of. Further, the organic amine ion includes methylamine (CH3NH3 + , MA +), dimethyldiammonium ion (MDA 2+ ), phenylethylammonium ion (PEA + ), oil ammonium ion (OA + ), at least one of ethylamino, propylamino, butylamino, pentylamino and hexylamino.

[0054] Optionally, the B ions include Pb 2+ (lead ion), Sn 2+ (tin ion), Be 2+ (beryllium ion), Mg 2+ (magnesium ion), Ca 2+ (Calcium ion), Sr 2+ (Strontium ion), Ba 2+ (barium ion), Zn 2+ (zinc ion), Ge 2+ (germanium ion), Fe 2+ (ferrous ion), Co 2+ (divalent cobalt ion), Cu 2+ (copper ions) and Ni 2+ (divalent nickel ions); more optionally, B ions include Pb 2+ (lead ions) and Sn 2+ (tin ions) or one or two thereof.

[0055] Optionally, the C ions include Cs + (cesium ion), Ag + (silver ion), K + (potassium ion) and Rb + (rubidium ions).

[0056] Optionally, the D ions include Bi 3+ (bismuth ion), Ni 3+ (trivalent nickel ion), Fe 3+ (ferric ion) and Cu 3+ (trivalent copper ions).

[0057] Optionally, the X ions include fluoride ions (F - ), chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ), thiocyanate ion (SCN - ), cyanate ion (CNO - ), oxygen cyanide ion (OCN - ), thiocyanate ion (OSCN - ), hydrogen sulfide ion (SH - ), cyanide ion (CN -), selenium cyanide ion (SeCN - ) at least one; optionally, the X ions include Cl - Br - and I - At least one of .

[0058] 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.

[0059] With the advancement of solar cell technology, people are demanding higher performance from solar cells. Tandem solar cells consist of at least two stacked cells. By combining the band gaps of each cell, they absorb sunlight across a wide wavelength range, improving its utilization. Consequently, tandem solar cells achieve high photoelectric conversion efficiency.

[0060] 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.

[0061] For tandem solar cells, particularly all-perovskite tandem solar cells, the bottom cell (also referred to herein as the first cell, the cell that first receives incident light) typically has a wide bandgap, while the top cell (also referred to herein as the second cell, the cell that receives incident light that has passed through the bottom cell) has a narrow bandgap. When a perovskite cell serves as the second cell, the light absorbing layer (also referred to herein as the second light absorbing layer) has a bandgap of 1.1 eV to 1.4 eV.

[0062] The band gap is equal to the difference between the LUMO energy level and the HOMO energy level. Due to the narrow band gap of the second light-absorbing layer, the HOMO energy level of the second light-absorbing layer is more positive. The hole transport material that requires band matching is primarily an organic hole transport material, resulting in a thickness of the second hole transport layer typically between 5nm and 10nm. This thickness restriction limits the second hole transport layer's ability to block electrons. Non-radiative recombination of holes and electrons still occurs in the second cell of the perovskite cell, limiting the potential for improvement in the photoelectric conversion efficiency of the tandem solar cell.

[0063] In view of this, embodiments of the present disclosure provide a tandem solar cell. A photovoltaic module, power generation device, and power consumption device comprising the tandem solar cell are provided. By disposing an electron blocking layer and a second hole transport layer in the second cell of a perovskite cell, the tandem solar cell achieves multi-layer electron blocking in the second cell, enhancing the electron blocking effect and reducing non-radiative recombination of electrons and holes, thereby improving the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0064] Tandem solar cells

[0065] FIG1 is a schematic diagram of an embodiment of a tandem solar cell according to the present disclosure. Tandem solar cell 10 includes a first electrode 11 and a second electrode 12; at least two cells disposed between first electrode 11 and second electrode 12; and a composite layer 15. The at least two cells include a first cell 13 and a second cell 14 sequentially arranged along a first direction. The composite layer 15 is disposed between first cell 13 and second cell 14, wherein the first direction is the direction of incident light. Second cell 14 includes a second hole transport layer 141, a second light absorbing layer 142, and a second electron transport layer 143 sequentially arranged along the first direction. Second cell 14 further includes an electron blocking layer 144 disposed between second hole transport layer 141 and second light absorbing layer 142.

[0066] In the present disclosure, on the basis of the second hole transport layer 141, by arranging the electron blocking layer 144, it is possible to achieve multi-layer blocking of electrons in the second battery unit 14, enhance the electron blocking effect, and further reduce the non-radiative recombination of electrons and holes, thereby improving the open circuit voltage and photoelectric conversion efficiency of the stacked solar cell.

[0067] The term "tandem solar cell" in this disclosure refers to a solar cell having a structure in which at least two battery cells are sequentially arranged along the incident direction of light. By stacking at least two battery cells, the utilization rate of incident sunlight can be increased.

[0068] The present disclosure has no particular limitation on the number of battery cells included in the stacked solar cell 10. For example, the number of battery cells included in the stacked solar cell can be 2, 3, 4, etc.

[0069] Hereinafter, the description will be made by taking as an example a case where the stacked solar cell 10 includes two battery cells (a first battery cell 13 and a second battery cell 14 ).

[0070] The first electrode 11 is made of a transparent conductive material. The present disclosure does not particularly limit the transparent conductive material of the first electrode 11. Exemplarily, the transparent conductive material includes at least one of indium tin oxide, fluorine-doped tin oxide (TCO), antimony-doped tin oxide, indium-doped tungsten oxide, indium-doped zinc oxide, aluminum-doped zinc oxide, and boron-doped zinc oxide.

[0071] The present disclosure has no particular limitation on the thickness of the first electrode 11 , and the thickness of the electrode conventionally used in the art may be adopted. For example, the thickness of the first electrode 11 may be 10-800 nm.

[0072] The second electrode 12 is made of a conductive material. The present disclosure does not particularly limit the conductive material of the second electrode 12. For example, the conductive material includes at least one of the aforementioned transparent conductive materials, metals and alloys thereof, and single-element carbon materials. Exemplarily, the metals and alloys thereof include at least one of gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, and tungsten. Exemplarily, the single-element carbon material includes at least one of graphite, graphene, and carbon nanotubes.

[0073] The present disclosure has no particular limitation on the thickness of the second electrode 12 , and the thickness of the second electrode 12 conventionally used in the art may be adopted. For example, the thickness of the second electrode 12 may be 10-100 nm.

[0074] The composite layer 15 is disposed between the first battery cell 13 and the second battery cell 14 and provides a location for the recombination of electrons generated by the first battery cell 13 and holes generated by the second battery cell 14. The present disclosure does not specifically limit the material comprising the composite layer 15. For example, the composite layer 15 may include at least one of gold, platinum, indium tin oxide, indium zinc oxide, iron, cobalt, nickel, zinc, manganese, cadmium, silver, and copper. The present disclosure does not specifically limit the thickness of the composite layer 15; a composite layer thickness commonly used in the art can be used.

[0075] The first cell 13 is disposed on the first electrode 11. The first cell 13 may have a relatively wide bandgap (e.g., a bandgap of 1.6 eV to 2.3 eV), which facilitates the first cell 13 and the narrow bandgap second cell 14 forming a tandem solar cell 10 with high photoelectric conversion efficiency. In one specific embodiment, the first cell is a perovskite solar cell.

[0076] In the present disclosure, the second battery unit 14 is arranged on the composite layer 15 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, and an electron blocking layer 144 arranged between the second hole transport layer 141 and the second light absorption layer 142.

[0077] The second hole transport layer 141 is arranged between the composite layer 15 and the second light absorbing layer 142, and is used to transport the holes generated by the excitation of the second light absorbing layer 142 to the composite layer 15. Due to the band gap of the second light absorbing layer 142, the material used in the second hole transport layer 141 is mostly an organic hole transport material. Exemplary organic hole transport materials include: [2-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid, poly (3,4-ethylenedioxythiophene), polystyrene sulfone, polystyrene sulfonic acid, poly (3-hexylthiophene), triphenylamine with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-phenylamino)carbazole-spirobifluorene, and at least one of polythiophene.

[0078] In some embodiments, the thickness of the second hole transport layer 141 is 5 nm to 10 nm. For example, the thickness of the second hole transport layer is 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or a range between any two values, but is not limited thereto. By arranging the electron blocking layer 144 and the second hole transport layer 141, a multi-layered barrier to electrons can be achieved in the second battery cell 14. Even if the thickness of the second hole transport layer 141 is within the above range, a strong barrier to electrons can still be generated in the second battery cell 14.

[0079] The second light absorbing layer 142 is made of a second light absorbing material. The second light absorbing material comprises a perovskite material. By designing the perovskite material, the second light absorbing layer 142 can have a narrow bandgap, which facilitates the formation of a tandem solar cell with high photoelectric conversion efficiency when the second cell 14 and the first cell 13 have a wide bandgap.

[0080] In some embodiments, the band gap of the second light absorbing layer 142 is 1.1 eV to 1.4 eV. The perovskite material used for 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, no restrictions here.

[0081] The present disclosure 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.

[0082] The second electron transport layer 143 is made of an electron transport material. The present disclosure does not particularly limit the electron transport material included in the second electron transport layer 143. Exemplary electron transport materials include: fullerene and its derivatives (e.g., C 60 ), metal oxides (such as oxides containing at least one of magnesium, cadmium, zinc, indium, lead, tungsten, bismuth, mercury, titanium, silver, manganese, iron, and vanadium), silicon oxide, strontium titanate, calcium titanate, lithium fluoride, and at least one of calcium fluoride.

[0083] The electron blocking layer 144 is disposed between the second light absorbing layer 142 and the second hole transporting layer 141 , and is configured to block electrons generated by the second light absorbing layer 142 .

[0084] In some embodiments, the electron blocking layer 144 is arranged as a film structure. Arranging the electron blocking layer as a film structure can further block the transmission of electrons. In other embodiments, the electron blocking layer 144 is arranged as island-shaped nanoparticles. Arranging the electron blocking layer 144 as island-shaped nanoparticles can reduce the lateral transmission of holes, which is conducive to improving the utilization rate of holes. Optionally, the electron blocking layer 144 is arranged as island-shaped nanoparticles.

[0085] The term "nanoparticles" in this disclosure refers to particles with a size (particle diameter) of the nanometer scale. The nanoparticles can be at least one of spherical, approximately spherical, and polyhedral. Exemplarily, the nanoparticles are at least one of spherical, oblate, and prolate ellipsoidal.

[0086] In some embodiments, the average particle size of the nanoparticles is 1 nm to 30 nm, optionally, the particle size of the nanoparticles is 1 nm to 20 nm, and further optionally, the particle size of the nanoparticles is 5 nm to 20 nm. For example, the average particle size of the nanoparticles is 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 25 nm, 30 nm, or a value within a range 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 further reducing the lateral transmission of holes.

[0087] In some embodiments, the resistivity of the electron blocking layer 144 is greater than or equal to 10 12 Ω·m. For example, the resistivity of the electron blocking layer 144 is 10 12 Ω·m, 2*10 12 Ω·m、3*10 12 Ω·m、4*10 12 Ω·m、5*10 12 Ω·m、6*10 12 Ω·m、7*1012 Ω·m、8*10 12 Ω·m、9*10 12 Ω·m, 10*10 12 Ω·m, 10 14 Ω·m, 10 15 Ω·m, 10 16 Ω·m, 10 17 Ω·m, 10 18 Ω·m or a value between any two values, but not limited thereto. The electron blocking layer 144 has a strong blocking effect on electrons. In some embodiments, the resistivity of the electron blocking layer 144 is greater than or equal to 10 12 Ω·m and less than or equal to 10 18 Ω·m.

[0088] In some embodiments, the material used for the electron blocking layer 144 includes at least one of an inorganic electron blocking material and an organic electron blocking material. The inorganic electron blocking material includes at least one of an inorganic oxide, an inorganic nitride, an inorganic carbide, an inorganic silicide, an inorganic sulfide, and a carbon material. Exemplarily, the materials used for the electron blocking layer 144 include: at least one of antimony oxide, aluminum oxide, cobalt oxide, boron oxide, bismuth oxide, chromium oxide, copper oxide, magnesium oxide, molybdenum oxide, silicon dioxide, vanadium oxide, zirconium oxide, aluminum nitride, aluminum nitride, boron nitride, calcium nitride, chromium nitride, europium nitride, magnesium nitride, silicon nitride, titanium nitride, vanadium nitride, zirconium nitride, gallium nitride, aluminum carbide, boron carbide, chromium carbide, molybdenum carbide, silicon carbide, titanium carbide, vanadium carbide, tungsten carbide, zirconium carbide, cobalt silicide, magnesium silicide, molybdenum silicide, niobium silicide, titanium silicide, tungsten silicide, zirconium silicide, aluminum sulfide, antimony sulfide, bismuth sulfide, barium sulfide, boron sulfide, calcium sulfide, chromium sulfide, cobalt sulfide, europium sulfide, gallium sulfide, magnesium sulfide, molybdenum sulfide, silicon disulfide, tungsten sulfide, vanadium sulfide, and zirconium sulfide. Exemplarily, the organic electron blocking material includes at least one of diphenylaminocarbazole and methyltriphenylaminecarboxylic acid.

[0089] In some embodiments, the material of the electron blocking layer 144 includes one or more of aluminum oxide, molybdenum oxide, silicon oxide, magnesium nitride, tungsten sulfide, molybdenum silicide, and boron carbide.

[0090] In some embodiments, the thickness of the electron blocking layer 144 is from 1 nm to 25 nm, optionally from 1 nm to 20 nm, and more optionally from 5 nm to 20 nm. For example, the thickness of the electron blocking layer 144 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, 22 nm, 25 nm or a value between any two numerical values, but not limited thereto. By controlling the thickness of the electron blocking layer 144 within the above range, the electron blocking layer 144 can produce less light absorption while playing the role of electron blocking, and is also beneficial to reducing the absorption of sunlight by the electron blocking layer 144.

[0091] According to the present disclosure, FIG. 2 exemplarily shows a structural diagram of a tandem solar cell 100 of another embodiment. In this embodiment, the first cell unit 13 is arranged on the first electrode 11 and includes a first hole transport layer 131, a first light absorption layer 132, a first hole blocking layer 133, a first electron transport layer 134, and a second hole blocking layer 135 arranged in sequence along the first direction. According to specific examples, the first light absorption layer contains a perovskite material. The composite layer 15 is arranged on the second hole blocking layer 135. The second cell unit is arranged on the composite layer 15. By arranging the first hole blocking layer 133 and the second hole blocking layer 135, multi-layer blocking of holes in the first cell unit 13 can be achieved, the hole blocking effect can be enhanced, and the non-radiative recombination of holes and electrons can be further reduced, thereby improving the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0092] The first hole transport layer 131 is arranged on the first electrode 11 and includes a hole transport material. The present disclosure places no particular limitation on the hole transport material included in the first hole transport layer 131. For example, the first hole transport layer 131 includes at least one of an inorganic hole transport material and an organic hole transport material. Exemplarily, the inorganic hole transport material includes at least one of metal oxides and cuprous thiocyanate. Exemplarily, the metal oxides include tin oxide (SnOx, where 1 < x < 2), nickel oxide (NiOx, 1 ≤ x ≤ 2), and cuprous oxide (Cu2O). Specific examples of the organic hole transport material are the same as those of the organic hole transport material in the above embodiment and will not be elaborated here.

[0093] The first light absorption layer 132 is arranged on the first hole transport layer 131, and the material used includes a perovskite material. To improve the photoelectric conversion efficiency, the first light absorption layer 132 including the perovskite material (which may be referred to as the first perovskite material hereinafter) is designed to have a relatively wide bandgap. The first perovskite material is well-known to those skilled in the art. Exemplarily, the first perovskite material includes FA0.8 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.

[0094] In some embodiments, the tandem solar cell is a tandem cell containing a perovskite material, and can be a tandem cell composed of a perovskite and other solar cells, such as a perovskite-gallium arsenide tandem solar cell or a perovskite-gallium phosphide tandem solar cell, wherein the perovskite cell is the second cell unit. In other embodiments, the tandem solar cell is an all-perovskite tandem solar cell, i.e., a perovskite-perovskite tandem solar cell, wherein both the first light absorbing layer 132 and the second light absorbing layer 142 comprise a perovskite material. Perovskite materials have high photoelectric conversion efficiency, and compared to other tandem solar cells, the photoelectric conversion efficiency of all-perovskite tandem solar cells is further improved.

[0095] In some embodiments, 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. Thus, the first light absorbing layer 132 helps absorb short-wavelength light, while the second light absorbing layer 142 helps absorb long-wavelength light. Together, these two layers can increase the spectral width of light that can be absorbed by the tandem solar cell, thereby improving the photoelectric conversion efficiency of the tandem solar cell. For example, the band gap of the first perovskite material is 1.6 eV-2.3 eV, while the band gap of the second perovskite material is 1.1 eV-1.4 eV.

[0096] The first hole blocking layer 133 is arranged on the first light absorbing layer 132 and includes a first hole blocking layer material. The first hole blocking material can use a conventional hole blocking material, but it is necessary to satisfy that the difference between the HOMO energy level of the first hole blocking material and the HOMO energy level of the first perovskite material is less than 0. Exemplarily, the first hole blocking material includes: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), SnO2, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI), 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene (B3PyPB), diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide (TSPO1), 2,7-bis(2,2'-bipyridin-5-yl)triphenylene (BPy-TP2), bis(8 -hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum, (6-(1,10-phenanthroline-3-yl)naphthalene-2-yl)diphenylphosphine oxide (Phen-NaDPO), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, and at least one of benzophenanthroline.

[0097] The first electron transport layer 134 is disposed on the first hole blocking layer 133 and includes an electron transport material. The present disclosure does not particularly limit the electron transport material included in the first electron transport layer 134. Specific examples of the electron transport material included in the first electron transport layer 134 are the same as those in the above embodiment and are not further described here.

[0098] The second hole blocking layer 135 is arranged on the first electron transport layer 134 and includes a second hole blocking layer material. The second hole blocking material can use a conventional hole blocking material. Exemplarily, the second hole blocking material may include at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), fullerene and its derivatives (e.g., PCBM), SnOz (1.5≤z≤2), and SnO2.

[0099] In some embodiments, the second battery cell further includes a third hole blocking layer disposed between the second light absorbing layer and the second electron transporting layer. The third hole blocking layer blocks holes, thereby further reducing non-radiative recombination of electrons and holes.

[0100] The third hole blocking layer includes a third hole blocking material. The third hole blocking material can be a conventional hole blocking material, but the difference between the HOMO energy level of the third hole blocking material and the HOMO energy level of the second light absorbing material must be less than 0. In some embodiments, the third hole blocking material can be the same as the first hole blocking material. In some embodiments, the third hole blocking material can further include: CuPc, 8-hydroxyquinoline-lithium, BN-ICz-1(C 50 H 40 BN3) at least one.

[0101] According to one embodiment, FIG3 exemplarily shows a structural diagram of a tandem solar cell 200 of this embodiment. In this embodiment, the first cell unit 13 is arranged on the first electrode 11 and includes a first hole transport layer 131, a first light absorbing layer 132, a first hole blocking layer 133, a first electron transport layer 134, and a second hole blocking layer 135 arranged in sequence along a first direction. The second cell unit 14 is arranged on the recombination layer 15 and includes a second hole transport layer 141, an electron blocking layer 144, a second light absorbing layer 142, a third hole blocking layer 145, and a second electron transport layer 143 arranged in sequence along the first direction. The second electrode 12 is arranged on the second electron transport layer 143. By arranging the first hole blocking layer 133, the second hole blocking layer 135, and the third hole blocking layer 145, multi-layer blocking of holes can be achieved, thereby enhancing the hole blocking effect and further improving the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0102] In this embodiment, the other layers are the same as those in the above embodiment and will not be described again here.

[0103] In some embodiments, the second battery cell further includes a fourth hole blocking layer disposed between the second electron transport layer and the second electrode. The fourth hole blocking layer blocks holes, thereby further reducing non-radiative recombination of electrons and holes.

[0104] According to one embodiment, FIG4 is an illustrative diagram of the structure of a stacked solar cell 300 of this embodiment. 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 absorbing layer 132, a first hole blocking layer 133, a first electron transport layer 134, and a second hole blocking layer 135 arranged in sequence along a first direction. The recombination layer 15 is arranged on the second hole blocking layer 135, and the second cell 14 is arranged on the recombination layer 15. The second cell 14 includes a second hole transport layer 141, an electron blocking layer 144, a second light absorbing layer 142, a third hole blocking layer 145, a second electron transport layer 143, and a fourth hole blocking layer 146 stacked in sequence, and the second electrode 12 is arranged on the fourth hole blocking layer 146. In this embodiment, by arranging the first hole blocking layer 133, the second hole blocking layer 135, the third hole blocking layer 145 and the fourth hole blocking layer 146, multi-layer hole blocking can be achieved, thereby enhancing the hole blocking effect and further improving the open circuit voltage and photoelectric conversion efficiency of the stacked solar cell.

[0105] The fourth hole blocking layer 146 includes a fourth hole blocking material. The present disclosure has no particular limitation on the fourth hole blocking material. For example, the fourth hole blocking material may include fullerene and its derivatives (e.g., C 60 The fourth hole-blocking material may be the same as or different from the second hole-blocking material.

[0106] In this embodiment, the other layers are the same as those in the above embodiment and will not be described again here.

[0107] The present disclosure does not particularly limit the preparation method of each functional layer of the stacked solar cell, and may include preparation methods commonly used in the art, such as evaporation, atomic layer deposition, spin coating, etc.

[0108] In some embodiments, the method for preparing the stacked solar cell includes the following steps S10 to S30.

[0109] S10, preparing a first battery cell 13 on the first electrode 11;

[0110] S20, preparing a composite layer 15 on the first battery cell 13;

[0111] S30, sequentially preparing a second hole transport layer 141, an electron blocking layer 144, a second light absorbing layer 142, and a second electron transport layer 143 on a side of the composite layer 15 away from the first battery unit 13 to obtain a second battery unit 14;

[0112] S30 , preparing a second electrode 12 on a side of the second electron transport layer 143 facing away from the second light absorption layer 142 .

[0113] Each film layer can be prepared by methods known to those skilled in the art to produce a stacked solar cell. The specific implementation method of each film layer is not limited and can be selected based on the above-described structure. For example, depending on the different film layers, methods such as spraying, sputtering, and vapor deposition can be selectively employed, as can those skilled in the art.

[0114] Furthermore, the vapor deposition method includes at least one of chemical vapor deposition, physical vapor deposition, plasma vapor deposition, and atomic layer deposition.

[0115] In some embodiments, the electron blocking layer 144 is prepared by atomic layer deposition or liquid phase methods (such as spin coating, slit coating, spray coating, etc.), which are not limited herein. Generally, the electron blocking layer 144 prepared by atomic layer deposition generally has a dense film structure, while the electron blocking layer 144 prepared by liquid phase methods generally has a film layer composed of island-shaped nanoparticles.

[0116] The embodiments of the present disclosure further provide a photovoltaic module. Typically, the photovoltaic module includes the aforementioned stacked solar cells, a welding ribbon connecting multiple stacked solar cells, a junction box for current transmission, and a battery packaging component.

[0117] 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.

[0118] In some embodiments, the cell encapsulation component includes an ethylene-vinyl acetate copolymer (EVA) film, which is disposed between the photovoltaic glass and the laminated solar cell to bond the photovoltaic glass and the solar cell.

[0119] In some embodiments, the cell packaging component includes a photovoltaic backsheet, which also serves to protect the laminated solar cells.

[0120] 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.

[0121] 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.

[0122] The embodiments of the present disclosure also provide a power generation device, comprising the stacked solar cell provided in the above embodiments.

[0123] The embodiments of the present disclosure further provide an electrical device, comprising the stacked solar cell provided in the above embodiments.

[0124] In some embodiments, the electrical device may also be a lighting device, an energy storage device, etc., and the embodiments of the present disclosure 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.

[0125] Example 1

[0126] Preparation of tandem solar cells

[0127] (1) Providing a first electrode: Take a 2.0*2.0 cm FTO conductive glass, remove 0.35 cm of FTO at each end by laser etching, and expose the glass substrate; ultrasonically clean the etched FTO conductive glass with cleaning solution, deionized water, and ethanol in sequence; blow the solvent out of the FTO conductive glass under a nitrogen gun, and place it in a UV ozone machine for further cleaning.

[0128] (2) Providing a first hole transport layer: On the FTO conductive glass treated with UV ozone, a 15 mg / mL NiOx (1≤x≤2) nanoparticle aqueous solution was spin-coated at a rate of 2000 rpm / s in a glove box to form a first hole transport layer with a thickness of 30 nm, and then thermally annealed at 150°C for 10 min.

[0129] (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).

[0130] (4) Providing a first electron transport layer: ALD deposits SnO2 with a thickness of 20 nm on the above-mentioned first light absorption layer as the first electron transport layer.

[0131] (5) Providing a composite layer: Providing a composite layer: Au with a thickness of 1 nm is evaporated on the second hole blocking layer as a composite layer.

[0132] (6) Providing a second hole transport layer: Spin-coat a mixed solution of poly (3,4-ethylenedioxythiophene) and polystyrene sulfone on the composite layer at a spin coating speed of 3000 rpm for 20 s, and then transfer to a hot plate and anneal at 150° C. for 15 min to form a second hole transport layer with a thickness of 10 nm.

[0133] (7) Providing an electron blocking layer: Al2O3 with a thickness of 10 nm is deposited on the second hole transport layer by atomic layer deposition as an electron blocking layer.

[0134] (8) 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).

[0135] (9) Providing a second electron transport layer: a 15 mg / mL fullerene derivative (PCBM) chlorobenzene solution was spin-coated on the second light absorbing layer to form a second electron transport layer with a thickness of 10 nm.

[0136] (10) Providing a second electrode: On the second electron transport layer, metal copper (Cu) is evaporated to a thickness of 100 nm as the second electrode.

[0137] Example 2

[0138] The difference from Example 1 is that step (7) is replaced by the following operation:

[0139] (7) Providing an electron blocking layer: Spin-coat a 5 mg / ml aqueous solution of MoO3 nanoparticles (average particle size of 17.3 nm) on the second hole transport layer at a spin-coating rate of 3000 rpm for 20 s, followed by annealing at 100°C for 10 min to obtain an electron blocking layer MoO3 with a thickness of 18.2 nm.

[0140] Example 3

[0141] The difference from Example 1 is that step (7) is replaced by the following operation:

[0142] (7) Providing an electron blocking layer: On the second hole transport layer, a solution of SiO2 nanoparticles (average particle size of 10.5 nm) with a spin coating concentration of 6.5 mg / ml was applied at a spin coating rate of 3000 rpm for 20 s, followed by annealing at 100°C for 10 min to obtain an electron blocking layer SiO2 with a thickness of 12.3 nm.

[0143] Example 4

[0144] The difference from Example 1 is that step (7) is replaced by the following operation:

[0145] (7) Providing an electron blocking layer: On the second hole transport layer, a 3.5 mg / ml aqueous solution of Mg3N2 nanoparticles (average particle size of 19.8 nm) was spin-coated at a rate of 3000 rpm for 20 seconds, followed by annealing at 100°C for 10 minutes to obtain an electron blocking layer Mg3N2 with a thickness of 20.8 nm.

[0146] Example 5

[0147] The difference from Example 1 is that step (7) is replaced by the following operation:

[0148] (7) Providing an electron blocking layer: On the above-mentioned second hole transport layer, a 5 mg / ml aqueous solution of WS2 nanoparticles (average particle size of 12.1 nm) was spin-coated at a rate of 3000 rpm and a spin-coating time of 20 s, followed by annealing at 100°C for 10 min to obtain an electron blocking layer WS2 with a thickness of 13.0 nm.

[0149] Example 6

[0150] The difference from Example 1 is that step (7) is replaced by the following operation:

[0151] (7) Providing an electron blocking layer: On the second hole transport layer, a 2.5 mg / ml aqueous solution of MoSi2 nanoparticles (average particle size of 15.6 nm) was spin-coated at a rate of 3000 rpm for 20 s, followed by annealing at 100°C for 10 min to obtain an electron blocking layer MoSi2 with a thickness of 17.3 nm.

[0152] Example 7

[0153] The difference from Example 1 is that step (7) is replaced by the following operation:

[0154] (7) Providing an electron blocking layer: On the second hole transport layer, a B4C nanoparticle (average particle size of 18.2 nm) aqueous solution with a spin coating concentration of 1.5 mg / ml was used at a spin coating rate of 3000 rpm and a spin coating time of 20 s. The resulting solution was then annealed at 100°C for 10 min to obtain an electron blocking layer B4C with a thickness of 19.0 nm.

[0155] Example 8

[0156] The difference from Example 1 is that step (7) is replaced by the following operation:

[0157] (7) Providing an electron blocking layer: A 3.5 mg / ml aqueous solution of Al2O3 nanoparticles (average particle size of 14.7 nm) was spin-coated on the second hole transport layer at a rate of 3000 rpm for 20 s, followed by annealing at 100°C for 10 min to obtain an electron blocking layer of Al2O3 with a thickness of 15.5 nm.

[0158] Comparative Example 1

[0159] A stacked solar cell was prepared according to the method of Example 1, except that no electron blocking layer was formed.

[0160] Performance testing of tandem solar cells

[0161] Open circuit voltage (Voc) and photoelectric conversion efficiency (PCE) testing of tandem solar cells

[0162] 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 fill factor (FF) of the tandem solar cell were calculated. PCE = Pout / Popt = Voc × Jsc × (Vmpp × Jmpp) / (Voc × Jsc) = Voc × Jsc × FF / Popt.

[0163] Pout, Popt, Vmpp, and Jmpp are the battery operating output power, incident light power, battery maximum power point voltage, and maximum power point current, respectively.

[0164] The performance of the stacked solar cells obtained in Examples 1 to 8 and Comparative Example 1 was tested. The test results are shown in Table 1.

[0165] Table 1

[0166] As can be seen from Table 1, the calcium tandem solar cell prepared in Example 1 has an electron blocking layer disposed between the second hole transport layer and the second light absorption layer. Compared with the calcium tandem solar cell prepared in Comparative Example 1, the calcium tandem solar cell prepared in Example 1 has improved open circuit voltage and photoelectric conversion efficiency.

[0167] It should be noted that the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and within the scope of the technical solution of the present disclosure, embodiments having substantially the same structure as the technical concept and exerting the same effects are all included in the technical scope of the present disclosure. In addition, within the scope of the present disclosure, various modifications that can be imagined by those skilled in the art to the embodiments, and other methods constructed by combining some of the constituent elements of the embodiments are also included in the scope of the present disclosure.

Claims

1. A tandem solar cell comprising a first electrode and a second electrode; at least two battery cells arranged between the first electrode and the second electrode; and a recombination layer; The at least two battery cells include a first battery cell and a second battery cell sequentially arranged along a first direction, and the composite layer is arranged between the first battery cell and the second battery cell, wherein: The first direction is the incident direction of light; Wherein, the second battery unit includes a second hole transport layer, a second light absorption layer and a second electron transport layer arranged in sequence; The second cell further includes an electron blocking layer disposed between the second hole transport layer and the second light absorbing layer.

2. The tandem solar cell according to claim 1, wherein: The thickness of the electron blocking layer is 1 nm to 25 nm.

3. The tandem solar cell according to claim 2, wherein: The thickness of the electron blocking layer is 1 nm to 20 nm.

4. The tandem solar cell according to claim 3, wherein: The thickness of the electron blocking layer is 5 nm to 20 nm.

5. The tandem solar cell according to claim 1, wherein: The electron blocking layer is arranged as a film structure or island-shaped distributed nanoparticles.

6. The tandem solar cell according to claim 5, wherein: The average particle size of the nanoparticles is 1 nm to 30 nm.

7. The tandem solar cell according to claim 6, wherein: The average particle size of the nanoparticles is 1 nm to 20 nm.

8. The tandem solar cell according to claim 7, wherein: The average particle size of the nanoparticles is 5 nm to 20 nm.

9. The tandem solar cell according to any one of claims 1 to 8, wherein: The thickness of the second hole transport layer is 5 nm to 10 nm.

10. The tandem solar cell according to claim 1, wherein: The first battery unit is arranged on the first electrode and includes a first hole transport layer, a first light absorption layer, a first hole blocking layer, a first electron transport layer and a second hole blocking layer arranged in sequence along a first direction.

11. The tandem solar cell according to any one of claims 1 to 8, wherein: The second cell further includes a third hole blocking layer disposed between the second light absorbing layer and the second electron transporting layer.

12. The tandem solar cell according to any one of claims 1 to 8, wherein: The second battery cell further includes a fourth hole blocking layer disposed between the second electron transport layer and the second electrode.

13. The tandem solar cell according to any one of claims 1 to 8, wherein: The resistivity of the electron blocking layer is greater than or equal to 10 12 Ω·m.

14. The tandem solar cell according to any one of claims 1 to 8, wherein: The thickness of the electron blocking layer is greater than or equal to 10 12 Ω·m and less than or equal to 10 18 Ω·m.

15. The tandem solar cell according to any one of claims 1 to 8, wherein: The material of the electron blocking layer includes at least one of an inorganic electron blocking material and an organic electron blocking material.

16. The tandem solar cell according to claim 15, wherein: The material of the electron blocking layer includes at least one of inorganic oxides, inorganic nitrides, inorganic carbides, inorganic silicides, inorganic sulfides, and carbon materials.

17. The tandem solar cell according to claim 16, wherein: The stacked solar cell satisfies one or more of the following conditions: (1) The inorganic oxide includes one or more of antimony oxide, aluminum oxide, cobalt oxide, boron oxide, bismuth oxide, chromium oxide, copper oxide, magnesium oxide, molybdenum oxide, silicon dioxide, vanadium oxide, and zirconium oxide; (2) The inorganic nitride includes one or more of aluminum nitride, aluminum nitride, boron nitride, calcium nitride, chromium nitride, europium nitride, magnesium nitride, silicon nitride, titanium nitride, vanadium nitride, zirconium nitride, and gallium nitride; (3) The inorganic carbide includes one or more of aluminum carbide, boron carbide, chromium carbide, molybdenum carbide, silicon carbide, titanium carbide, vanadium carbide, tungsten carbide, and zirconium carbide; (4) The inorganic silicide includes one or more of cobalt silicide, magnesium silicide, molybdenum silicide, niobium silicide, titanium silicide, tungsten silicide, and zirconium silicide; (5) The inorganic sulfide includes one or more of aluminum sulfide, antimony sulfide, bismuth sulfide, barium sulfide, boron sulfide, calcium sulfide, chromium sulfide, cobalt sulfide, europium sulfide, gallium sulfide, magnesium sulfide, molybdenum sulfide, silicon disulfide, tungsten sulfide, vanadium sulfide, and zirconium sulfide; (6) The organic electron blocking material includes one or more of diphenylaminocarbazole and methyltriphenylamine carboxylic acid.

18. The tandem solar cell according to any one of claims 1 to 8, wherein: The band gap of the second light absorbing layer is narrower than the band gap of the first light absorbing layer.

19. The tandem solar cell according to claim 18, wherein: The stacked solar cell satisfies one or more of the following conditions: (1) The first light absorbing layer includes a perovskite material; (2) The band gap of the first light absorbing layer is 1.6 eV-2.3 eV; (3) The second light absorbing layer includes a perovskite material; (4) The band gap of the second light absorbing layer is 1.1 eV to 1.4 eV.

20. A photovoltaic module comprising the tandem solar cell according to any one of claims 1 to 19.

21. A power generation device comprising the tandem solar cell according to any one of claims 1 to 19.

22. An electrical device comprising the tandem solar cell according to any one of claims 1 to 19.

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