Tandem solar cell, photovoltaic module, photovoltaic system, electrical apparatus, and power generation apparatus

Abstract

The present application relates to a tandem solar cell, a photovoltaic module, a photovoltaic system, an electrical apparatus, and a power generation apparatus. The tandem solar cell comprises: a first cell unit, which comprises a first light absorbing layer; a second cell unit, which comprises a second light absorbing layer, the second light absorbing layer comprising a silver bismuth sulfide material; and a connecting layer, which is disposed between the first cell unit and the second cell unit, and connects the first cell unit and the second cell unit. A band gap of the first light absorbing layer is greater than a band gap of the second light absorbing layer. In the tandem solar cell containing the silver bismuth sulfide material, said material has good stability, and the tandem solar cell can absorb a wider spectral range and effectively utilize solar energy. Therefore, the tandem solar cell can have good device stability, and provide good photoelectric conversion efficiency over a long-term working process.

Description

Multilayer solar cells, photovoltaic modules, photovoltaic systems, electrical appliances and power generation devices Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a tandem solar cell, a photovoltaic module, a photovoltaic system, an electrical appliance, and a power generation device. Background Technology

[0002] A solar cell is an electronic device that can directly convert light energy into electrical energy. The main working principle of a solar cell is the photovoltaic effect: when sunlight or other light sources shine on the semiconductor material of a photovoltaic device, the energy of photons is absorbed by the semiconductor, exciting the generation of electron-hole pairs. Under the influence of an electric field inside the semiconductor, electrons and holes move in different directions, creating a potential difference across the device. When an external circuit is connected, an electric current is generated.

[0003] Compared to single-junction solar cells, tandem solar cells consist of multiple semiconductor materials with different band gaps stacked together to form multiple pn junctions. The working principle is that materials with different band gaps can absorb sunlight of different wavelengths, thereby making more efficient use of sunlight and achieving more efficient photon capture. Multiple pn junctions work together to improve the open-circuit voltage and short-circuit current of the cell, thereby improving the conversion efficiency.

[0004] However, the lifespan of traditional tandem solar cells is still relatively short, and how to extend the lifespan of tandem solar cells is one of the key issues that urgently need to be addressed.

[0005] Summary of the Invention

[0006] To achieve the above objectives, this application provides a tandem solar cell, photovoltaic module, photovoltaic system, electrical appliance, and power generation device, which have a long service life.

[0007] In a first aspect, this application provides a tandem solar cell, comprising:

[0008] The first battery cell includes a first light-absorbing layer;

[0009] The second battery cell includes a second light-absorbing layer, the second light-absorbing layer comprising an aluminosilicate-type material; and...

[0010] A connecting layer is disposed between the first battery cell and the second battery cell, and connects the first battery cell and the second battery cell;

[0011] The band gap of the first light absorption layer is larger than that of the second light absorption layer.

[0012] Silver bismuth sulfide (SPFS) is a type of semiconductor material with light absorption properties and a high absorption coefficient. It can be used as a photosensitive material to absorb light energy and exhibits good stability. It can be used as the light-absorbing layer in narrow bandgap solar cells, replacing the less stable narrow bandgap absorbing layer in tandem solar cells. Therefore, a tandem solar cell incorporating SPFS, with a wide bandgap first cell and a narrow bandgap second cell, can absorb a wider spectral range. This allows for efficient utilization of solar energy, and the higher stability of the narrow bandgap cell results in good device stability and high photoelectric conversion efficiency during long-term operation.

[0013] In some embodiments, the silver bismuth sulfide type material includes one or more of cubic rock salt phase crystal forms and hexagonal phase crystal forms.

[0014] In some embodiments, the grain size of the silver bismuth sulfide type material is ≥10nm, which can be selected as 10nm~10μm, or more preferably 10nm~500nm or 50nm~200nm.

[0015] In some embodiments, the silver bismuth sulfide type material includes one or both of polycrystalline and monocrystalline forms.

[0016] In some embodiments, the band gap of the silver bismuth sulfide material is 0.8 eV to 1.4 eV, optionally 0.8 eV to 1.2 eV, and more preferably 0.9 eV to 1.1 eV. With a band gap within the above range, the silver bismuth sulfide material can serve as a good narrow band gap light-absorbing material, possessing advantages such as high absorption coefficient, suitable band gap, good charge transport performance, and good material stability. Its thin film can achieve high current density within a relatively small thickness range.

[0017] In some embodiments, the band gap of the first light-absorbing layer is 1.5 eV to 1.9 eV, optionally 1.53 eV to 1.65 eV. This effectively absorbs both long-wavelength and short-wavelength light, thereby improving photoelectric conversion efficiency.

[0018] In some embodiments, the thickness of the first light-absorbing layer is 200nm to 1000nm, and can be selected as 400nm to 600nm.

[0019] In some embodiments, the thickness of the second light-absorbing layer is 10 nm to 20 μm, optionally 10 nm to 10 μm; more preferably 30 nm to 500 nm or 50 nm to 200 nm.

[0020] In some embodiments, the stacked solar cell includes:

[0021] First electrode and second electrode;

[0022] The first battery cell includes a first electrode disposed between the first light-absorbing layer and the connecting layer. The second battery cell includes a second electrode disposed on the side of the second light-absorbing layer away from the connecting layer.

[0023] In some embodiments, the first battery cell further includes one or both of a first charge transport layer and a second charge transport layer;

[0024] The first charge transport layer is located between the first electrode and the first light absorption layer;

[0025] The second charge transport layer is located between the first light absorption layer and the connecting layer;

[0026] In this configuration, one of the first charge transport layer and the other of the second charge transport layer is an electron transport layer, and the other is a hole transport layer.

[0027] In some embodiments, the second battery cell further includes one or both of a third charge transport layer and a fourth charge transport layer;

[0028] The third charge transport layer is located between the connecting layer and the second light absorption layer;

[0029] The fourth charge transport layer is located between the second light absorption layer and the second electrode;

[0030] Among them, one of the third charge transport layer and the other of the fourth charge transport layer is an electron transport layer and the other is a hole transport layer.

[0031] By setting up a charge transport layer in this way, the efficiency of charge transport and extraction in battery cells can be improved.

[0032] In some embodiments, the electron transport layer comprises one or more of the following materials and their derivatives, dopants, and passivated materials:

[0033] [6,6]-phenyl C61 butyrate methyl ester, [6,6]-phenyl C71 butyrate methyl ester, fullerene C60, fullerene C61, fullerene C70, tin dioxide, zinc oxide, perylene imide materials and naphthalene imide materials.

[0034] In some embodiments, the thickness of the electron transport layer is 1 nm to 300 nm, and can be selected as 1 nm to 100 nm.

[0035] In some embodiments, the hole transport layer comprises one or more of the following materials and their derivatives, dopants, and passivated materials:

[0036] Nickel oxide, molybdenum oxide, molybdenum sulfide, cuprous oxide, cuprous iodide, cuprous thiocyanate, 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, poly-3-hexylthiophene, methoxytriphenylamine-fluoroformamidinium, triphenylamine with a triphenylene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-4-anilinecarbazole-spirobifluorene, polythiophene, and self-assembled monomolecule materials.

[0037] In some embodiments, the thickness of the hole transport layer is 1 nm to 500 nm, and can be selected as 1 nm to 300 nm or 1 nm to 100 nm.

[0038] In some implementations, one or more of the following conditions are met:

[0039] (1) The first battery cell further includes a first passivation layer, which is disposed on the side of the first light absorption layer facing the first electrode. Optionally, the first passivation layer is disposed on at least a portion of the surface of the first light absorption layer facing the first electrode.

[0040] (2) The first battery cell further includes a second passivation layer, which is disposed on the side of the first light-absorbing layer facing the connecting layer. Optionally, the second passivation layer is disposed on at least a portion of the surface of the first light-absorbing layer facing the connecting layer.

[0041] (3) The second battery cell further includes a third passivation layer, which is disposed on the side of the second light absorption layer facing the connecting layer. Optionally, the third passivation layer is disposed on at least a portion of the surface of the second light absorption layer facing the connecting layer.

[0042] (4) The second battery cell further includes a fourth passivation layer, which is disposed on the side of the second light absorption layer facing the second electrode. Optionally, the fourth passivation layer is disposed on at least a portion of the surface of the second light absorption layer facing the second electrode.

[0043] In some implementations, one or more of the following conditions are met:

[0044] (1) The first battery cell includes a first passivation layer and a first charge transport layer, wherein the first passivation layer is disposed between the first charge transport layer and the first light absorption layer;

[0045] (2) The first battery cell includes a second passivation layer and a second charge transport layer, wherein the second passivation layer is disposed between the first light absorption layer and the second charge transport layer;

[0046] (3) The second battery cell includes a third passivation layer and a third charge transport layer, wherein the third passivation layer is disposed between the third charge transport layer and the second light absorption layer;

[0047] (4) The second battery cell includes a fourth passivation layer and a fourth charge transport layer, wherein the fourth passivation layer is disposed between the second light absorption layer and the fourth charge transport layer.

[0048] In some implementations, one or more of the following conditions are met:

[0049] (1) The first battery cell includes a first passivation layer, the thickness of which is 1 nm to 20 nm;

[0050] (2) The first battery cell includes a second passivation layer, the thickness of which is 1 nm to 20 nm;

[0051] (3) The second battery cell includes a third passivation layer, the thickness of which is 1 nm to 20 nm;

[0052] (4) The second battery cell includes a fourth passivation layer, the thickness of which is 1 nm to 20 nm.

[0053] In some embodiments, the material in the first passivation layer and / or the second passivation layer is anionicly or cationicly bonded to the material of the first light-absorbing layer; and / or,

[0054] The material in the third passivation layer and / or the fourth passivation layer is chemically bonded to the anionic or cationic material of the second light-absorbing layer.

[0055] In some implementations, one or more of the following conditions are met:

[0056] (1) The first battery cell further includes a first barrier layer, which is disposed between the first electrode and the first light-absorbing layer;

[0057] (2) The first battery cell further includes a second barrier layer, which is disposed between the first light-absorbing layer and the connecting layer;

[0058] (3) The second battery cell further includes a third barrier layer, which is disposed between the connecting layer and the second light-absorbing layer;

[0059] (4) The second battery cell further includes a fourth barrier layer, which is disposed between the second light-absorbing layer and the second electrode;

[0060] Among them, one of the first blocking layer and the second blocking layer is an electron blocking layer and the other is a hole blocking layer;

[0061] One of the third and fourth blocking layers is an electron blocking layer, and the other is a hole blocking layer.

[0062] In some implementations, one or more of the following conditions are met:

[0063] (1) The first battery cell includes a first barrier layer and a first charge transport layer; optionally, the first barrier layer is disposed between the first electrode and the first charge transport layer; optionally, the first barrier layer is disposed between the first charge transport layer and the first light absorption layer.

[0064] (2) The first battery cell further includes a second barrier layer and a second charge transport layer; optionally, the second barrier layer is disposed between the second charge transport layer and the connecting layer; optionally, the second barrier layer is disposed between the first light absorption layer and the second charge transport layer;

[0065] (3) The second battery cell further includes a third barrier layer and a third charge transport layer; optionally, the third barrier layer is disposed between the connecting layer and the third charge transport layer; optionally, the third barrier layer is disposed between the third charge transport layer and the second light absorption layer;

[0066] (4) The second battery cell further includes a fourth barrier layer and a fourth charge transport layer; optionally, the fourth barrier layer is disposed between the fourth charge transport layer and the connecting layer; optionally, the fourth barrier layer is disposed between the second light absorption layer and the fourth charge transport layer.

[0067] In some embodiments, the LUMO energy level of the hole blocking layer material is lower than the conduction band bottom (CBM) of the light absorption layer material of the corresponding battery cell, and the HOMO energy level of the hole blocking layer material is lower than the valence band top (VBM) of the light absorption layer material of the corresponding battery cell.

[0068] Optionally, the hole-blocking layer comprises one or more of 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline, SnO2, ZnO, and cerium oxide.

[0069] In some embodiments, the LUMO energy level of the electron blocking layer material is higher than the conduction band bottom (CBM) of the light absorbing layer material of the corresponding battery cell, and the HOMO energy level of the electron blocking layer material is higher than the valence band top (VBM) of the light absorbing layer material of the corresponding battery cell.

[0070] Optionally, the electron blocking layer comprises one or more of molybdenum oxide, vanadium oxide, LiF, and Al2O3.

[0071] In some embodiments, the thickness of the first barrier layer and the second barrier layer are each independently 0.5 nm to 50 nm.

[0072] In some embodiments, the stacked solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together.

[0073] Optionally, the stacked solar cell includes a first electrode, a first barrier layer, a first charge transport layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second charge transport layer, a connecting layer, a third charge transport layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth charge transport layer, a fourth barrier layer, and a second electrode, all stacked together.

[0074] In some embodiments, the materials of the first electrode and the second electrode each independently include one or more of organic conductive materials, inorganic conductive materials, and organic-inorganic mixed conductive materials.

[0075] In some implementations, one or more of the following conditions are met:

[0076] (1) The inorganic conductive material includes one or more of carbon materials, metallic materials and their alloys, and transparent conductive metal oxides;

[0077] (2) The organic conductive material includes one or more of polyacrylic acid, polyimide, polyaniline, polythiophene and its derivatives and polypyrrole.

[0078] In some embodiments, at least one of the first electrode and the second electrode is a light-transmitting electrode.

[0079] In some embodiments, the stacked solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together.

[0080] The band gap of the first light-absorbing layer is larger than that of the second light-absorbing layer, and the first electrode is a light-transmitting electrode;

[0081] Wherein, the first charge transport layer is an electron transport layer and the second charge transport layer is a hole transport layer; or, the first charge transport layer is a hole transport layer and the second charge transport layer is an electron transport layer.

[0082] In some embodiments, the connection layer includes a composite layer;

[0083] Wherein, the first charge transport layer and the third charge transport layer are electron transport layers, and the second charge transport layer and the fourth charge transport layer are hole transport layers; or, the first charge transport layer and the third charge transport layer are hole transport layers, and the second charge transport layer and the fourth charge transport layer are electron transport layers.

[0084] In this way, holes from the first cell and electrons from the second cell, or electrons from the first cell and holes from the second cell, recombine and annihilate in the composite layer, thereby achieving the circuit connection between the two cell units. The connecting layer includes the composite layer. The fabrication of tandem solar cells is simple; the top cell can be directly deposited on the bottom cell to form a single, complete cell with two electrodes, forming a two-end tandem solar cell.

[0085] In some embodiments, the composite layer is made of one or more of metallic materials and transparent conductive oxides.

[0086] In some implementations, one or more of the following conditions are met:

[0087] (1) The metallic material includes one or more of gold, copper, silver, platinum, aluminum and iron;

[0088] (2) The components of the transparent conductive oxide layer include one or more of FTO, ITO, AZO, BZO, IZO, IGZO and ATO.

[0089] In some embodiments, the thickness of the composite layer is 0.1 nm to 200 nm, and optionally 0.5 nm to 10 nm.

[0090] In some embodiments, the stacked solar cell further includes a third electrode and a fourth electrode, the connecting layer includes an insulating layer, the third electrode is disposed between the first light-absorbing layer and the connecting layer, and the fourth electrode is disposed between the connecting layer and the second light-absorbing layer;

[0091] Optionally, the third electrode and the fourth electrode are light-transmitting electrodes;

[0092] Optionally, the first electrode and the second electrode are light-transmitting electrodes;

[0093] Optionally, the stacked solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a third electrode, a connecting layer, a fourth electrode, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together; more preferably, one of the first charge transport layer and the second charge transport layer is an electron transport layer and the other is a hole transport layer; one of the third charge transport layer and the fourth charge transport layer is an electron transport layer and the other is a hole transport layer.

[0094] This insulating connecting layer circuitically isolates the first and second battery cells. Each of the two cells has two electrodes, for a total of four electrodes. The circuits of the two cells are independent, forming a four-terminal tandem solar cell. Four-terminal tandem solar cells have lower requirements for current and voltage matching of the cell cells because each cell operates independently, unlike two-terminal tandem solar cells which require more precise current and voltage matching. Four-terminal tandem solar cells allow for more flexible combination of different types and performance of cell cells to adapt to various application scenarios and needs, and to some extent reduce performance loss caused by mutual interference between cell cells.

[0095] Furthermore, since the third and fourth electrodes are located in the middle of the tandem solar cell, in order to further increase the light energy utilization rate of the tandem solar cell and enable the remaining solar energy after absorption by the previous cell to enter the next cell, the third and fourth electrodes can also be set as light-transmitting electrodes.

[0096] In some embodiments, the tandem solar cell includes a first electrode, a first light-absorbing layer, a common fifth electrode, a second light-absorbing layer, and a second electrode stacked sequentially. The fifth electrode, as the common electrode, can serve as either a positive or negative output electrode. The first and second electrodes are electrodes with opposite polarities to the common fifth electrode, thus forming a three-terminal tandem solar cell. In a three-terminal tandem solar cell, two cell units are connected in parallel, eliminating the problem of current mismatch.

[0097] In some embodiments, the chemical formula of the silver bismuth sulfide type material is MX, where M is a cation and X is an anion; optionally, X includes one or more divalent anions; optionally, M includes one or more cations. Thus, A and X occupy the cation and anion sites of the sodium chloride crystal structure, respectively, and are arranged alternately in space to form a face-centered cubic structure, forming a cubic rock salt phase crystal type silver bismuth sulfide type material.

[0098] In some embodiments, the divalent anion includes one or more of divalent inorganic anions and divalent organic anions.

[0099] In some embodiments, the divalent inorganic anion includes O 2- S 2- Se 2- and Te 2- One or more of the following; optionally including S 2- .

[0100] In some embodiments, M includes one or more of metal cations and organic cations;

[0101] Optionally, the metal cation includes Ag. + Li + Na + K + 、Rb + Cs + Cu + Ni 2+ Cu 2+ Zn 2+ Co 2+ Bi 3+ Ga 3+ In 3+ Sb 3+ Al 3+ 、Tl 3+ and Co 3+ One or more of the following;

[0102] Optionally, the organic cation includes at least one of organic amine ions, formamidinium ions, and imidazole ions.

[0103] In some embodiments, M includes a first cation A and a second cation B of different elemental types;

[0104] Optionally, the first cation A and the second cation B each independently comprise Ag. + Li + Na + K + 、Rb + Cs + Cu + Ni 2+ Cu 2+ Zn 2+ Co 2+ Bi 3+ Ga 3+ In 3+ Sb 3+ Al3+ 、Tl 3+ and Co 3+ One or more of the following;

[0105] Optionally, the first cation A includes Ag. + Li + Na + K + 、Rb + and Cs + One or more of the following;

[0106] Optionally, the second cation B comprises Bi. 3+ .

[0107] In some embodiments, the silver-bismuth sulfide type material comprises chemical formula A x B y Compounds of X2, where the values ​​of x and y make A x B y The compounds of X2 are electrically neutral as a whole.

[0108] In some embodiments, the silver-bismuth sulfide material comprises a compound with the chemical formula ABX2, where the first cation A is a monovalent cation, the second cation B is a trivalent cation, and X is a divalent anion. Perovskite materials generally contain tin, which is divalent. Divalent tin ions are unstable and easily oxidized. Therefore, this silver-bismuth sulfide material with the chemical formula ABX2 does not contain divalent cations, such as divalent tin ions, and thus it is not easily oxidized and exhibits good stability in oxidizing environments.

[0109] In some embodiments, the silver-bismuth sulfide type material comprises chemical formula A x B y X' z X” 2-z The compound X includes divalent anions X' and X'', where z is 0 to 2.

[0110] In some embodiments, the silver-bismuth sulfide type material comprises materials with the chemical formula ABX'. z X” 2-z The compound has the first cation A being a monovalent cation, the second cation B being a trivalent cation, and X comprising divalent anions X' and X'', with z ranging from 0 to 2.

[0111] In some implementations, one or more of the following conditions are met:

[0112] (1) The divalent anion X' and the divalent anion X” have different element types;

[0113] (2) X' is S 2- z is not 0;

[0114] (3) X” is selected from O 2- Se 2- and Te 2- One or more of them.

[0115] In some embodiments, the silver-bismuth sulfide type material includes AgBiS2 and AgBiS. z O 2-z AgBiS z Se 2-z AgBiS z Te 2-z One or more of the following, where z is 0 to 2.

[0116] In some embodiments, the first light-absorbing layer comprises one or more semiconductor materials selected from perovskite, silver bismuth sulfide, crystalline silicon, copper indium gallium selenide, cadmium telluride, copper zinc tin sulfide, and gallium arsenide; optionally, the first light-absorbing layer comprises a perovskite material.

[0117] In some embodiments, the perovskite material comprises one or more of a compound with the chemical formula A'B'Y3 and a compound with the chemical formula A'2CDY6;

[0118] Among them, A' includes monovalent cations, B' includes divalent cations, C includes monovalent cations, D includes trivalent cations, and Y includes monovalent anions;

[0119] Optionally, A' is a monovalent cation, B' is a divalent cation, C is a monovalent cation, D is a trivalent cation, and Y is a monovalent anion.

[0120] In some implementations, one or more of the following characteristics are satisfied:

[0121] (1) A' includes one or more of monovalent metal cations and monovalent organic cations;

[0122] (2) B' includes one or more of divalent metal cations and divalent organic cations;

[0123] (3) C includes one or more of monovalent metal cations and monovalent organic cations;

[0124] (4) D includes one or more of trivalent metal cations and trivalent organic cations;

[0125] (5) Y includes one or more of monovalent inorganic anions and monovalent organic anions.

[0126] In some implementations, one or more of the following characteristics are satisfied:

[0127] (1) The monovalent metal cation in A' includes Li + Na + K + 、Rb + and Cs + One or more of the following, wherein the monovalent organic cation includes one or more of organic amine ions, formamidin ions, and imidazole ions;

[0128] (2) The divalent metal cations in B' include one or more of the following divalent cations: lead, tin, zinc, titanium, nickel, iron, cobalt, copper, gallium, germanium, beryllium, magnesium, calcium, strontium, barium, indium, manganese, chromium, molybdenum and europium;

[0129] (3) The monovalent metal cation in C includes Cs + Ag + K + and Rb + One or more;

[0130] (4) The trivalent metal cations in D include Bi 3+ Ni 3+ Fe 3+ Sb 3+ In 3+ and Cu 3+ One or more of the following;

[0131] (5) Y includes one or more of halide ions and halide-like ions; optionally, Y includes F - Cl - ,Br - I - CN - CH3COO - SCN - BF4 - SeCN - PF6 - One or more of them.

[0132] In a second aspect, this application provides a photovoltaic module, including the tandem solar cell provided in the first aspect of this application.

[0133] In a third aspect, this application provides a photovoltaic system, including one or more of the tandem solar cells provided in the first aspect of this application and the photovoltaic modules provided in the second aspect of this application.

[0134] In a fourth aspect, this application provides an electrical device including one or more of the tandem solar cells provided in the first aspect of this application and the photovoltaic modules provided in the second aspect of this application.

[0135] In a fifth aspect of this application, a power generation device is provided, comprising one or more of the tandem solar cells provided in the first aspect of this application and the photovoltaic modules provided in the second aspect of this application.

[0136] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0137] To better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments or examples, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0138] Figure 1 is a schematic diagram of a solar cell according to an embodiment of this application.

[0139] Figure 2 is a schematic diagram of a solar cell according to another embodiment of this application.

[0140] Figure 3 is a schematic diagram of a solar cell according to another embodiment of this application.

[0141] Figure 4 is a schematic diagram of a solar cell according to another embodiment of this application.

[0142] Figure 5 is a schematic diagram of a solar cell according to another embodiment of this application.

[0143] Figure 6 is a schematic diagram of a solar cell according to another embodiment of this application.

[0144] Figure 7 is a cross-sectional schematic diagram of a first cell unit in a solar cell according to an embodiment of this application, divided into multiple sub-cells.

[0145] Figure 8 is a schematic diagram of an electrical device using a solar cell as a power source according to an embodiment of this application.

[0146] 10. Solar cell; 110. First light-absorbing layer; 120. Second light-absorbing layer; 210. First electrode; 220. Second electrode; 230. Third electrode; 240. Fourth electrode; 310. First charge transport layer; 320. Second charge transport layer; 330. Third charge transport layer; 340. Fourth charge transport layer; 410. First passivation layer; 420. Second passivation layer; 430. Third passivation layer; 440. Fourth passivation layer; 610. First barrier layer; 620. Second barrier layer; 630. Third barrier layer; 640. Fourth barrier layer; 710. First charge injection layer; 720. Second charge injection layer; 730. Third charge injection layer; 740. Fourth charge injection layer; 800. Substrate;

[0147] P1, P1 channel; P2, P2 channel; P3, P3 channel; 11. Active region; 12. Dead region;

[0148] 20. Electrical appliances. Detailed Implementation

[0149] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0150] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be combined arbitrarily, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this document; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, stating that a parameter is an integer ≥2 is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, stating that a parameter is an integer selected from "2-10" is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0151] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0152] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0153] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The term "implementation" as used herein has a similar understanding.

[0154] Those skilled in the art will understand that the order in which the steps are written in the methods of various embodiments or examples does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0155] In this application, unless otherwise specified, A (e.g., B) means that B is a non-limiting example of A, and it is understood that A is not limited to B.

[0156] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0157] Compared to single-junction solar cells, tandem solar cells, due to their multiple stacked semiconductor materials with different band gaps, can absorb sunlight of different wavelengths, thus utilizing sunlight more effectively and achieving higher conversion efficiency.

[0158] Typically, a tandem solar cell consists of a wide-bandgap absorber layer and a narrow-bandgap absorber layer stacked together. Taking the incident light direction from the wide-bandgap absorber layer to the narrow-bandgap absorber layer as an example, the wide-bandgap absorber layer absorbs high-energy photons because the wide bandgap requires high-energy photons to be excited; even higher energy is needed from the valence band to the conduction band, such as shorter wavelengths like ultraviolet light. The remaining light then enters the narrow-bandgap absorber layer and is absorbed by it. The narrow-bandgap absorber layer only requires low-energy photons to be excited, such as longer wavelengths like infrared light. Furthermore, since longer wavelengths of light diffuse deeper, the narrow-bandgap absorber layer is generally placed at the bottom. In this way, the cell converts light energy into electrical energy based on the photovoltaic effect.

[0159] Commonly used narrow bandgap light-absorbing layers include crystalline silicon light-absorbing layers or tin-based perovskite materials. For tin-based perovskite materials, divalent tin is easily oxidized to tetravalent tin, making them sensitive to water and oxygen. This leads to their decomposition due to thermal instability, light exposure, and chemical instability. Therefore, tin-based perovskite materials exhibit poor stability when used in narrow bandgap tandem solar cells, thus affecting the photoelectric conversion efficiency of the cells. For example, the crystal structure of tin-based perovskite materials is prone to change, leading to decomposition and disrupting the structural integrity of the material, resulting in reduced stability.

[0160] One embodiment of this application provides a tandem solar cell, comprising:

[0161] The first battery cell includes a first light-absorbing layer;

[0162] The second battery cell includes a second light-absorbing layer comprising an aluminosilicate-type material; and...

[0163] A connecting layer is disposed between the first battery unit and the second battery unit, and connects the first battery unit and the second battery unit;

[0164] The band gap of the first light absorption layer is larger than that of the second light absorption layer.

[0165] Silver bismuth sulfide (SPFS) is a type of semiconductor material with light absorption properties and a high absorption coefficient. It can be used as a photosensitive material to absorb light energy and exhibits good thermal stability. It can be used as the light-absorbing layer in narrow bandgap solar cells, replacing the less stable narrow bandgap absorbing layer in tandem solar cells. Therefore, a tandem solar cell incorporating SPFS as a narrow bandgap cell, where the first cell unit is a wide bandgap cell unit and the second cell unit is a narrow bandgap cell unit, results in a tandem solar cell that can absorb a wider spectral range. This allows for efficient utilization of solar energy, and the higher stability of the narrow bandgap cell unit contributes to the superior device stability and high photoelectric conversion efficiency during long-term operation.

[0166] Furthermore, in the tandem solar cell, the second light-absorbing layer is a narrow bandgap light-absorbing layer, and the first light-absorbing layer is a wide bandgap light-absorbing layer.

[0167] Traditional tandem solar cells often use tin-containing perovskite materials as the narrow bandgap light-absorbing layer. Since narrow bandgap perovskite materials generally contain tin, tin has two main problems: firstly, tin is divalent, and divalent tin ions are unstable and easily oxidized; secondly, narrow bandgap perovskite materials also contain lead, and the mismatch in crystallization rates between tin and lead leads to structural instability. This application uses a silver-bismuth sulfide type material as the light-absorbing material for the narrow bandgap cell, which avoids the problems of easily oxidized divalent tin ions and the mismatch in crystallization rates between tin and lead.

[0168] As used in this application, the term "layer" refers to any substantially layered structure. A layer may have a thickness that varies over its length. Typically, the thickness of a layer is approximately constant. The "thickness" of a layer as used in this application refers to the average thickness of the layer. The thickness of a layer can be measured using methods conventional in the art. For example, it can be measured using a Zygo NewView 9000 white light interferometer.

[0169] In some embodiments, the crystal form of the silver bismuth sulfide type material includes one or more of the cubic rock salt phase crystal form and the hexagonal phase crystal form.

[0170] The hexagonal crystal system has a 6-fold symmetry axis or a 6-fold inversion axis, which is the upright crystallographic axis C-axis. The other three horizontal crystallographic axes form a 120-degree angle between their positive ends. Among the axial angles α, β, and γ, α = β = 90°, and γ = 120°; among the axial lengths a, b, and c, a = b ≠ c.

[0171] Among them, the cubic rock salt phase crystal form has a crystal space group The cubic rock salt phase crystal form belongs to the cubic crystal system and is also known as the sodium chloride crystal structure.

[0172] In some embodiments, the silver bismuth sulfide type material includes a cubic rock salt phase crystal form; further, the silver bismuth sulfide type material is a cubic rock salt phase crystal form.

[0173] In some embodiments, the cubic rock salt phase crystal form of the silver bismuth sulfide type material may have the chemical formula MX, where M is a cation and X is an anion.

[0174] Furthermore, M may include one or more cations, and X may include one or more anions. A and X occupy the cation and anion sites of the sodium chloride crystal structure, respectively, and are arranged alternately in space to form a face-centered cubic structure.

[0175] In some embodiments, X comprises one or more divalent anions. Further, the divalent anion comprises one or more of divalent inorganic anions and divalent organic anions.

[0176] Furthermore, divalent inorganic anions include chalcogen elements, specifically O. 2- S 2- Se 2- and Te 2- One or more of the following; optionally including S 2- .

[0177] In some embodiments, M includes one or more of monovalent cations, divalent cations, and trivalent cations.

[0178] In some embodiments, M includes one or more of a metal cation and an organic cation; wherein the valence state of the metal cation and the organic cation can be any one or any combination of monovalent to trivalent.

[0179] Furthermore, the metal cations include Ag. + Li + Na + K + 、Rb + Cs + Cu + Ni 2+ Cu 2+ Zn 2+ Co 2+ Bi 3+ Ga 3+ In 3+ Sb 3+ Al 3+ 、Tl 3+ and Co 3+ One or more of the following. Optionally, the metal cation includes Li. + Sodium ions (Na) + ), potassium ions (K) + ), rubidium ions (Rb + ), cesium ions (Cs) + ), silver ions (Ag) + One or more of the following. More preferably, the metal cation includes silver ions (Ag). + ).

[0180] Furthermore, organic cations may include organic amine ions, formamidinium ions (HC(NH2)2), etc. + FA + One or more of the following: ) and imidazole ions; further, organic amine ions include methylamine ions (CH3NH3) + MA + ), dimethyl diammonium ion (MDA) 2+ ), phenylethylammonium ion (PEA) + ), oleyl ammonium ion (OA) +( ), one or more of ethylamine ions, propylamine ions, butylamine ions, pentamine ions, and hexamine ions.

[0181] Among them, imidazole-type ions refer to those containing an imidazole group and the imidazole group being charged; as an example, it includes one or more of imidazole ions and imidazole derivative ions.

[0182] Furthermore, M includes at least two cations, namely a first cation A and a second cation B. The first cation A and the second cation B are of different elemental types.

[0183] Furthermore, the first cation A and the second cation B each independently include one or more of metal cations and organic cations, wherein the valence states of the metal cations and organic cations can be any one or any combination of monovalent to trivalent.

[0184] Furthermore, the first cation A and the second cation B each independently include metal cations, and the two cations have different element types.

[0185] Furthermore, the first cation A and the second cation B each independently include Ag. + Li + Na + K + 、Rb + Cs + Cu + Ni 2+ Cu 2+ Zn 2+ Co 2+ Bi 3+ Ga 3+ In 3+ Sb 3+ Al 3+ 、Tl 3+ and Co 3+ One or more of them, and the two have different types of elements.

[0186] Optionally, the first cation A includes Ag. + Optionally, the second cation B includes Bi. 3+ .

[0187] In some embodiments, the silver bismuth sulfide type material includes material with the chemical formula A. x B y Compounds of X2. The values ​​of x and y can make A... x B y The compound of X2 is electrically neutral as a whole. In other words, the values ​​of x and y can make A... x B yThe algebraic sum of the valences of all atoms in the compound X2 is equal to zero.

[0188] Furthermore, the values ​​of x and y are any numbers from 0 to 4. For example, they can be 0, 0.1, 0.2, 0.3, 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, 2.1, 2.5, 2.8, 3, 3.2, 3.4, 3.5, 3.6, 3.8, 4, or any two of the above point values ​​as endpoints.

[0189] Furthermore, X is a divalent anion, and the values ​​of x and y can make A x B y The compound of X2 only needs to be electrically neutral.

[0190] Furthermore, divalent anions include O 2- S 2- Se 2- and Te 2- One or more of them; optionally, X includes S. 2- .

[0191] Further, the first cation A is a monovalent cation; optionally, the first cation includes Ag. + Li + Na + K + 、Rb + Cs + and Cu + One or more of them.

[0192] Further, the second cation B is a trivalent cation; optionally, the second cation includes Bi. 3+ Ga 3+ In 3+ Sb 3 +、Al 3 +、Tl 3 + and Co 3+ One or more of them.

[0193] In some embodiments, the silver bismuth sulfide material comprises a compound with the chemical formula ABX2, wherein the first cation A is a monovalent cation, the second cation B is a trivalent cation, and X is a divalent anion. Perovskite materials generally contain tin, which is divalent. Divalent tin ions are unstable and easily oxidized. Therefore, this silver bismuth sulfide material with the chemical formula ABX2 does not contain divalent tin ions, and thus it is not easily oxidized and exhibits good stability in oxidizing environments.

[0194] Furthermore, X includes one or more divalent anions.

[0195] Furthermore, if X includes divalent anions X' and X' with different elements, then the chemical formula is A. x B y The compound of X2 has the chemical formula A. x B y X' z X” 2-z , where z is 0 to 2. The value of z is any number from 0 to 2. For example, it can be 0, 0.1, 0.2, 0.3, 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, or any two of the above point values ​​as endpoints.

[0196] When z is 0, the divalent anion X' does not exist; when z is 2, the divalent anion X” does not exist. When z is an intermediate value between 0 and 2 (not an extreme value), the divalent anions X' and X” are of different element types, indicating that two different divalent anions X' and X” exist simultaneously. Furthermore, X' is S 2- z is not 0. Furthermore, X” is selected from O. 2- Se 2- and Te 2- One or more of the following. Further, the chemical formula is A. x B y The compound of X2 has the chemical formula A. x B y S z X” 2-z .

[0197] As an example, the chemical formula is A x B y Compounds of X2 include, but are not limited to, A. x B y S2, A x B y S z O 2-z A x B y S z Se 2-z A x B y S z Te 2-z One or more of them.

[0198] Furthermore, if the first cation A is a monovalent cation, the second cation B is a trivalent cation, and X includes divalent anions X' and X'', then the compound with the chemical formula ABX2 has the chemical formula ABX'. z X” 2-z, where z is 0 to 2. The value of z is any number from 0 to 2. For example, it can be 0, 0.1, 0.2, 0.3, 0.5, 0.6, 0.8, 1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, or any two of the above point values ​​as endpoints.

[0199] When z is 0, the divalent anion X' does not exist; when z is 2, the divalent anion X” does not exist; when z is an intermediate value between 0 and 2 (not an extreme value), it indicates that two different divalent anions X' and X” exist simultaneously. Further, X' is S 2- z is not 0. Furthermore, X” is selected from O. 2- Se 2- and Te 2- One or more of the following. Further, a compound with the chemical formula ABX2, whose chemical formula is ABS. z X” 2-z .

[0200] As an example, compounds with the chemical formula ABX2 include, but are not limited to, AgBiS2 and AgBiS. z O 2-z AgBiS z Se 2-z AgBiS z Te 2-z One or more of them.

[0201] Furthermore, taking AgBiS2 as an example, it includes one or more of cubic rock salt phase crystal forms and hexagonal phase crystal forms. Optionally, the above-mentioned tandem solar cells include AgBiS2 with a cubic rock salt phase crystal form. AgBiS2 with a cubic rock salt phase crystal form has advantages such as high absorption coefficient, suitable band gap, good charge transport performance, and good material stability.

[0202] Silver bismuth sulfide materials can be formed by methods such as hydrothermal method, solvothermal method, chemical vapor deposition (CVD), precursor pyrolysis method, and sol-gel method.

[0203] In some embodiments, the silver bismuth sulfide type material is a nanocrystal, such as quantum dots, with a particle size of 2 nm to 10 nm. However, the synthesis of nanocrystals is complex, and their surfaces contain a large number of surface traps, resulting in low carrier transport rates and severe recombination, which restricts charge extraction efficiency.

[0204] In some embodiments, the grain size of the silver bismuth sulfide type material is ≥10nm, and can be selected from 10nm to 10μm. Examples include 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, or any two of the above values ​​as end values.

[0205] In some embodiments, the grain size of the silver bismuth sulfide material is 10 nm to 5 μm or 500 nm to 5 μm. Optionally, the grain size of the silver bismuth sulfide material is 10 nm to 1 μm or 500 nm to 1 μm. The large grain size and small grain boundaries of the silver bismuth sulfide material can reduce the nonradiative recombination of electrons and holes at the grain boundaries.

[0206] In some embodiments, the grain size of the silver bismuth sulfide type material is 1 μm to 10 μm. Optionally, the grain size of the silver bismuth sulfide type material is 5 μm to 10 μm, or 1 μm to 5 μm, or 4 μm to 6 μm.

[0207] In some embodiments, the grain size of the silver bismuth sulfide type material is 10 nm to 500 nm, or 50 nm to 500 nm. Optionally, the grain size of the silver bismuth sulfide type material is 10 nm to 400 nm, or 50 nm to 400 nm. Optionally, the grain size of the silver bismuth sulfide type material is 10 nm to 200 nm, or 50 nm to 200 nm. Optionally, the grain size of the silver bismuth sulfide type material is 10 nm to 100 nm, or 50 nm to 100 nm, or 10 nm to 50 nm, or 50 nm to 90 nm, or 60 nm to 90 nm, or 60 nm to 80 nm, or 60 nm to 70 nm, or 50 nm to 60 nm, or 20 nm to 50 nm, or 20 nm to 40 nm, or 20 nm to 35 nm, or 25 nm to 35 nm.

[0208] In some embodiments, the crystal structure of the silver bismuth sulfide type material includes one or both of polycrystalline and single-crystal types. Polycrystalline refers to crystal grains with grain boundaries, which are the interface regions between different grains in a polycrystalline material. Single-crystal refers to a crystal composed of structural units arranged in a long-range ordered manner in three-dimensional space. Polycrystalline refers to a material composed of multiple grains, which are crystalline bodies formed by the ordered arrangement of atoms or molecules. The lattice of each grain is periodically arranged, but the orientation of these grains is arbitrary. Different orientations of grains result in grain boundaries between crystal grains. Single-crystal crystals, due to their ordered and regular internal atomic arrangement, with consistent atomic arrangement in all directions, do not have grain boundaries. In other words, silver bismuth sulfide type materials include one or both of polycrystalline and single-crystal silver bismuth sulfide type materials.

[0209] In some embodiments, the band gap of the silver bismuth sulfide material is 0.8 eV to 1.4 eV, optionally 0.8 eV to 1.2 eV, and more preferably 0.9 eV to 1.1 eV. As an example, the band gap of the silver bismuth sulfide material can be 0.8 eV, 0.85 eV, 0.9 eV, 0.95 eV, 1 eV, 1.1 eV, 1.2 eV, 1.3 eV, 1.4 eV, or any two of the above values ​​as endpoints. With a band gap within the above range, the silver bismuth sulfide material can serve as a good narrow band gap light-absorbing material, possessing advantages such as high absorption coefficient, suitable band gap, good charge transport performance, and good material stability. Its thin film can achieve high current density within a relatively small thickness range.

[0210] For example, in some embodiments, the first cation A is a monovalent cation, the second cation B is a trivalent cation, and X is a divalent anion, then the chemical formula is A. x B y The compound of X2 has the chemical formula ABX2. Therefore, this silver-bismuth sulfide material with the chemical formula ABX2 does not contain divalent cations, such as divalent tin ions. Consequently, it is not easily oxidized, exhibits good stability in oxidizing environments, and does not suffer from the problem of mismatched crystallization rates between tin and lead.

[0211] In some embodiments, the thickness of the second light-absorbing layer is 10nm to 20μm, and examples include 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 200nm, 250nm, 30 The range is defined by 0nm, 350nm, 400nm, 450nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, or any two of the above point values ​​as endpoints.

[0212] Furthermore, the thickness of the second light-absorbing layer can be 10 nm to 10 μm, or 500 nm to 10 μm. Optionally, the thickness of the second light-absorbing layer can be 10 nm to 5 μm, or 500 nm to 5 μm.

[0213] Further, the thickness of the second light-absorbing layer is 1 μm to 20 μm. Optionally, the thickness of the second light-absorbing layer is 5 μm to 20 μm.

[0214] Further, the thickness of the second light-absorbing layer is 10nm to 1000nm, or 50nm to 1000nm. Optionally, the thickness of the second light-absorbing layer is 10nm to 800nm, or 50nm to 800nm. Optionally, the thickness of the second light-absorbing layer is 10nm to 500nm, 30nm to 500nm, 50nm to 400nm, or 20nm to 500nm. Optionally, the thickness of the second light-absorbing layer is 20nm to 200nm, 50nm to 200nm, or 100nm to 200nm, or 20nm to 60nm, or 30nm to 60nm, or 30nm to 50nm.

[0215] Silver bismuth sulfide type materials have a high light absorption coefficient, and high current density can be achieved in thin films with a small thickness range.

[0216] In some embodiments, the band gap of the first light-absorbing layer is 1.5 eV to 1.9 eV, and may be 1.53 eV to 1.65 eV. As an example, the band gap of the first light-absorbing layer may be 1.5 eV, 1.53 eV, 1.55 eV, 1.58 eV, 1.6 eV, 1.61 eV, 1.62 eV, 1.63 eV, 1.65 eV, 1.66 eV, 1.68 eV, 1.7 eV, 1.75 eV, 1.8 eV, 1.85 eV, 1.9 eV, or any two of the above values ​​as endpoints.

[0217] Furthermore, the band gap of the second light-absorbing layer is 0.8 eV to 1.2 eV, and can be selected as 0.9 eV to 1.1 eV. As an example, the band gap of the silver bismuth sulfide type material can be 0.8 eV, 0.85 eV, 0.9 eV, 0.95 eV, 1 eV, 1.1 eV, 1.2 eV, or any two of the above values ​​as endpoints. With a band gap within the above range, the silver bismuth sulfide type material can serve as a good narrow band gap light-absorbing material, possessing advantages such as high absorption coefficient, suitable band gap, good charge transport performance, and good material stability. Its thin film can achieve high current density within a relatively small thickness range.

[0218] Furthermore, the band gap of the first light absorption layer is 1.5 eV to 1.9 eV, and the band gap of the second light absorption layer is 0.9 eV to 1.9 eV; this effectively absorbs both long-wavelength and short-wavelength light, thereby improving the photoelectric conversion efficiency. Furthermore, the band gap of the first light absorption layer is 1.53 eV to 1.65 eV, and the band gap of the second light absorption layer is 0.9 eV to 1.1 eV; this effectively absorbs both long-wavelength and short-wavelength light, thereby improving the photoelectric conversion efficiency.

[0219] In some embodiments, the first light-absorbing layer comprises one or more semiconductor materials selected from perovskite, silver bismuth sulfide, crystalline silicon, copper indium gallium selenide, cadmium telluride, copper zinc tin sulfide, and gallium arsenide. In this application, the first light-absorbing layer can be combined with a second light-absorbing layer of silver bismuth sulfide to enable the resulting tandem solar cell to absorb a wider spectral range, thereby improving the efficient utilization of solar energy.

[0220] In some embodiments, the first light-absorbing layer comprises one or more semiconductor materials selected from perovskite, copper indium gallium selenide, cadmium telluride, copper zinc tin sulfide, and gallium arsenide.

[0221] Furthermore, the first light-absorbing layer comprises a perovskite material. Further, the first light-absorbing layer is a perovskite material layer.

[0222] In some embodiments, the perovskite material includes one or more of a compound with the chemical formula A'B'Y3 and a compound with the chemical formula A'2CDY6;

[0223] Wherein, A' includes a monovalent cation, B' includes a divalent cation, C includes a monovalent cation, D includes a trivalent cation, and Y includes a monovalent anion. Further, A' is a monovalent cation, B' is a divalent cation, C is a monovalent cation, D is a trivalent cation, and Y is a monovalent anion.

[0224] In some embodiments, A' comprises one or more of a monovalent metal cation and a monovalent organic cation. Further, the monovalent metal cation in A' includes Li. + Na + K + 、Rb + and Cs + One or more of the following, wherein the monovalent organic cation includes one or more of organic amine ions, formamidinium ions, and imidazole-type ions. Further, the organic amine ion includes methylamine ions (CH3NH3). + MA + ), dimethyl diammonium ion (MDA) 2+ ), phenylethylammonium ion (PEA) + ), oleyl ammonium ion (OA) + ( ), one or more of ethylamine ions, propylamine ions, butylamine ions, pentamine ions, and hexamine ions.

[0225] In some embodiments, B' comprises one or more of a divalent metal cation and a divalent organic cation. Further, the divalent metal cation in B' comprises one or more of the divalent cations of the following elements: lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, beryllium, magnesium, calcium, strontium, barium, indium, aluminum, manganese, chromium, molybdenum, and europium.

[0226] In some embodiments, C comprises one or more of a monovalent metal cation and a monovalent organic cation. Further, the monovalent metal cation in C comprises Cs. + Ag + K + and Rb + One or more of them.

[0227] In some embodiments, D comprises one or more of a trivalent metal cation and a trivalent organic cation. Further, the trivalent metal cation in D includes Bi. 3+ Ni 3+ Fe 3+ Sb 3+ In 3+ and Cu 3+ One or more of them.

[0228] In some embodiments, Y comprises one or more of a monovalent inorganic anion and a monovalent organic anion. Further, Y comprises one or more of a halide ion and a halide-like ion; optionally, Y comprises F. - Cl - ,Br - I - CN - CH3COO - SCN - BF4 - SeCN - PF6 - One or more of them.

[0229] In some embodiments, the thickness of the first light-absorbing layer is 200 nm to 1000 nm. As an example, the thickness of the first light-absorbing layer is 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, or 1000 nm; optionally, it is 400 nm to 600 nm.

[0230] The perovskite material layer can be prepared using methods commonly used in the art, including but not limited to sol-gel methods, coating, and multi-source co-evaporation. It is understood that coating can be achieved through methods including but not limited to spin coating, slot coating, brush coating, wiping coating, scraping coating, screen coating, and spray coating. Furthermore, the perovskite material layer is a three-dimensional perovskite thin film.

[0231] As an example, the perovskite material in the perovskite material layer may include one or more of CsFAPbX3, CsMAPbX3, CsFAMAPbX3, CsPbX3, MAPbX3, FAPbX3, CsFAPbSnX3, CsMAPbSnX3, CsFAMAPbSnX3, CsPbSnX3, MAPbSnX3, and FAPbSnX3. Further, as an example, the perovskite material in the above-mentioned perovskite light-absorbing layer may be selected from one or more of CsFAPbI3, CsPbI3, and FAPbI3.

[0232] As an example, the general formula for perovskite materials is as follows: Cs a FA b MA c Pb d Sn e I f Br g , among them, a=0~0.05, b=0.8~0.95, c=0~0.1, d=0.5~1, e=0~0.5, f=2.0~3, g=0~1, a+b+c=1, d+e=1, f+g=3.

[0233] In some embodiments, the tandem solar cell includes: a first electrode and a second electrode; a first cell includes a first electrode disposed on the side of a first light-absorbing layer away from the connecting layer; and a second cell includes a second electrode disposed on the side of a second light-absorbing layer away from the connecting layer.

[0234] In some embodiments, at least one of the first and second electrodes is a light-transmitting electrode. Further, only one of the first and second electrodes is a light-transmitting electrode, serving as the incident side for sunlight. Further still, both the first and second electrodes are light-transmitting electrodes, and both electrodes can serve as the incident side for solar energy. If solar light can be incident from both sides, it is beneficial to increase the intensity of sunlight received by the tandem solar cell.

[0235] Here, a light-transmitting electrode refers to an electrode that is transparent to visible light. Further, the light-transmitting electrode has a visible light transmittance ≥50%, which can be selected as ≥60%, ≥70%, ≥80%, ≥85%, or ≥90%. As an example, the visible light transmittance of the light-transmitting electrode can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or within a range formed by any two of the above values ​​as endpoints. Further, the visible light transmittance of the light-transmitting electrode can be 50%–100%, which can be selected as 60%–80%, 80%–100%, or 80%–95%.

[0236] In some embodiments, the first battery cell further includes one or both of a first charge transport layer and a second charge transport layer;

[0237] The first charge transport layer is located between the first electrode and the first light absorption layer;

[0238] The second charge transport layer is located between the first light absorption layer and the connecting layer;

[0239] Among them, one of the first charge transport layer and the other of the second charge transport layer is an electron transport layer and the other is a hole transport layer.

[0240] In some embodiments, the second battery cell further includes one or both of a third charge transport layer and a fourth charge transport layer;

[0241] The third charge transport layer is located between the connecting layer and the second light absorption layer;

[0242] The fourth charge transport layer is located between the second light absorption layer and the second electrode;

[0243] Among them, the third charge transport layer and the fourth charge transport layer are electron transport layers and hole transport layers, respectively.

[0244] By setting up a charge transport layer in this way, the efficiency of charge transport and extraction in battery cells can be improved.

[0245] In some embodiments, the connecting layer includes a composite layer, where holes from the first cell and electrons from the second cell, or electrons from the first cell and holes from the second cell, recombine and annihilate in the composite layer, thereby achieving a circuit connection between the two cell units. The composite layer facilitates the fabrication of tandem solar cells, allowing the top cell to be directly deposited on the bottom cell to form a single, complete cell with two electrodes, thus creating a two-end tandem solar cell.

[0246] The working principle of a tandem solar cell, with a composite layer as the connecting layer, is as follows: Two cell units with different bandgap are connected in series through the composite layer, allowing them to absorb sunlight of different wavelengths, thereby improving the overall photoelectric conversion efficiency of the cell. Sunlight enters from the bottom cell, which first absorbs a portion of the sunlight and generates a certain voltage and current. The sunlight not absorbed by the bottom cell passes through the bottom cell to the top cell, which then absorbs this portion of sunlight and generates additional voltage and current. The voltages of the two cells are superimposed, and the current is matched (taking the lower value) for output. This structural design is relatively simple, reducing the number of electrodes and connecting layers, thus lowering the complexity and cost of the cell. By selecting appropriate cell unit combinations and optimizing the tandem structure, high photoelectric conversion efficiency can be achieved. Due to its relatively simple structure, it offers better stability and reduces potential points of failure or performance degradation.

[0247] In some embodiments, the tandem solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode, all stacked together. Further, the charge transport layers located on either side of the composite layer cannot simultaneously be electron transport layers or hole transport layers. In other words, the first and third charge transport layers are electron transport layers, and the second and fourth charge transport layers are hole transport layers. Alternatively, the first and third charge transport layers are hole transport layers, and the second and fourth charge transport layers are electron transport layers.

[0248] In some embodiments, the composite layer comprises one or more of metallic materials, transparent conductive oxides, and carbon materials.

[0249] Furthermore, the components of the transparent conductive oxide layer include, but are not limited to, one or more of FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), IGZO (indium gallium zinc oxide), and ATO (antimony tin oxide). Furthermore, the metallic materials include, but are not limited to, one or more of gold, copper, silver, platinum, aluminum, and iron. Furthermore, the carbon materials include, but are not limited to, one or more of graphite, graphene, and carbon nanotubes.

[0250] Furthermore, the composite layer can be a stack of one or more of the following: a metal layer, a transparent conductive oxide layer, and a carbon material layer, such as a composite layer including an Au layer and an ITO layer.

[0251] Furthermore, the metal layer includes, but is not limited to, a gold layer.

[0252] In some embodiments, the thickness of the composite layer is 0.1nm to 200nm. For example, it can be 0.1nm, 0.5nm, 0.8nm, 1nm, 1.2nm, 1.5nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 20nm, 30nm, 40nm, 500nm, 60nm, 70nm, 90nm, 100nm, 130nm, 150nm, 160nm, 180nm, 190nm, or 200nm, or within the range formed by any two of the above point values ​​as end values, and can be selected as 0.5nm to 10nm, 0.5nm to 3nm, or further 0.8nm to 1.2nm.

[0253] In other embodiments, the connecting layer includes an insulating layer. The tandem solar cell also includes a third electrode and a fourth electrode, the third electrode being disposed between the first light-absorbing layer and the connecting layer, and the fourth electrode being disposed between the connecting layer and the second light-absorbing layer. Thus, the connecting layer containing the insulating layer circuitically isolates the first and second battery cells. Each of the two battery cells has two electrodes, for a total of four electrodes, and the circuits of the two battery cells are independent of each other, forming a four-terminal tandem solar cell.

[0254] The first battery cell includes a first electrode, a first light-absorbing layer, and a third electrode stacked sequentially. The second battery cell includes a fourth electrode, a second light-absorbing layer, and a second electrode stacked sequentially.

[0255] The working principle of this tandem solar cell with an insulating layer is as follows: each cell has an independent electrode, which can independently receive sunlight and generate voltage and current. Then, the outputs of two cells are connected in parallel through an external circuit, so that the total voltage is the lower of the two cell voltages, and the total current is equal to the sum of the currents of the two cell cells.

[0256] Four-terminal tandem solar cells have lower requirements for current and voltage matching of cell units because each cell unit operates independently, unlike two-terminal tandem solar cells which require more precise current and voltage matching. Four-terminal tandem solar cells can more flexibly combine different types and performance of cell units to adapt to different application scenarios and needs, and to a certain extent reduce the performance loss caused by mutual interference between cell units.

[0257] Furthermore, since the third and fourth electrodes are located in the middle of the tandem solar cell, in order to further increase the light energy utilization rate of the tandem solar cell and enable the remaining solar energy after absorption by the previous cell to enter the next cell, the third and fourth electrodes can also be set as light-transmitting electrodes.

[0258] Furthermore, at least one of the first and second electrodes is a light-transmitting electrode. Further, only one of the first and second electrodes is a light-transmitting electrode, which serves as the incident side for sunlight. Further, both the first and second electrodes are light-transmitting electrodes, and both electrodes can serve as the incident side for solar energy. If solar light can be incident from both sides, it is beneficial to increase the intensity of sunlight received by the tandem solar cell.

[0259] In some embodiments, as an example of a four-terminal tandem solar cell, the tandem solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a third electrode, a connecting layer, a fourth electrode, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together.

[0260] Because the circuits of the cell units in a four-terminal tandem solar cell are independent, the types of charge transport layers located on both sides of the connecting layer or insulating layer are unrestricted and can be arbitrarily combined. In other words, the materials of the second and third charge transport layers can be the same or different, and they can each be independently an electron transport layer or a hole transport layer. Furthermore, one of the first and second charge transport layers can be an electron transport layer and the other a hole transport layer; one of the third and fourth charge transport layers can be an electron transport layer and the other a hole transport layer.

[0261] In some embodiments, the material of the insulating layer includes, but is not limited to, glass or an insulating adhesive. Further, the glass is transparent glass; further, the insulating adhesive is a transparent adhesive.

[0262] In some embodiments, the electron transport layer includes, but is not limited to, one or more of the following materials and their derivatives, dopants, and passivated materials: methyl [6,6]-phenyl C61 butyrate (PC61BM), methyl [6,6]-phenyl C71 butyrate (PC71BM), fullerene C60 (C60), fullerene C61, fullerene C70 (C70), tin dioxide (SnO2), zinc oxide (ZnO), perylene imide (PDI) materials, naphthalene imide (NDI) materials, etc.

[0263] Furthermore, the thickness of the electron transport layer is 1 nm to 300 nm. For example, it can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 150 nm, 160 nm, 180 nm, 200 nm, 210 nm, 220 nm, 250 nm, 260 nm, 280 nm, 300 nm, or any two of the above values ​​as endpoints. Further, the thickness of the electron transport layer is 1 nm to 100 nm; further, it can be 5 nm to 100 nm; further, it can be 1 nm to 50 nm.

[0264] In some embodiments, the hole transport layer includes, but is not limited to, one or more of the following materials and their derivatives, dopants, and passivated materials:

[0265] Nickel oxide, molybdenum oxide, molybdenum sulfide, cuprous oxide, cuprous iodide, cuprous thiocyanate, 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirobisfluorene (Spiro-OMeTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, poly-3-hexylthiophene, methoxytriphenylamine-fluoroformamidinium, triphenylene-based triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-4-anilinecarbazole-spirobisfluorene, polythiophene, and self-assembled monomolecule materials.

[0266] In some embodiments, the self-assembled monomolecular material satisfies the structure shown in the following general formula: QLA, wherein Q is selected from substituted or unsubstituted carbazole or triphenylamine groups, L is selected from substituted or unsubstituted alkylene chains, and A is selected from oxyacid groups.

[0267] In some embodiments, in the self-assembled monomolecule material, the substituents of the substituted or unsubstituted carbazole or triphenylamine group include any one of the following: halogen groups, alkoxy groups, oxyacid groups, substituted or unsubstituted aromatic groups with 6 to 15 cyclic atoms, substituted or unsubstituted heteroaromatic groups with 5 to 15 cyclic atoms, and substituted or unsubstituted alkyl groups with 1 to 5 carbon atoms. In this application, the structure of the substituents of the substituted or unsubstituted carbazole or triphenylamine group allows the organic compound to have energy levels more compatible with perovskite materials, further improving the performance of solar cells when used in the fabrication of hole transport layers.

[0268] In some embodiments, the substituted or unsubstituted alkylene chains in the self-assembled monomolecule material include any one of the following: alkylene chains with 2 to 11 carbon atoms substituted or unsubstituted by halogen groups, alkoxy groups, oxyacid groups, aromatic groups with 6 to 15 cyclic atoms, or heteroaromatic groups with 5 to 15 cyclic atoms. By controlling the number of carbon atoms in L and its substituents, the steric hindrance of the organic compound is reduced while its hydrophobicity is improved, further enhancing the photoelectric conversion efficiency and stability of the solar cell.

[0269] In some embodiments, in the self-assembled monomolecular material, the oxyacid group is selected from any one of phosphonic acid groups, hypophosphite groups, sulfonic acid groups, carboxylic acid groups, sulfinic acid groups, boric acid groups, or silicate groups.

[0270] In some embodiments, the halogen group includes any one of F, Cl, Br, and I.

[0271] In some embodiments, the heteroatoms in the heteroaromatic group are selected from at least one of N, O, and S, which gives the organic compound an energy level that is more compatible with commonly used metal oxide hole transport materials and perovskite materials, thereby further improving the performance of solar cells when used to prepare passivation films for solar cells.

[0272] In some embodiments, the alkoxy group is typically represented by RO-, such as methoxy CH3O-, ethoxy C2H5O-, propoxy C3H7O-, etc.

[0273] In some embodiments, the self-assembled monomolecular material includes [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), and [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphonic acid (Br At least one of the following is selected: [MeO-2PACz], [Me-2PACz], [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), and [2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid (Br-2PACz). The self-assembled monomolecule material selected from the above materials exhibits good hole transport efficiency and good energy level matching with the perovskite layer, which is beneficial for improving the photoelectric conversion efficiency of perovskite solar cells.

[0274] Furthermore, the thickness of the hole transport layer is 1nm to 500nm. For example, it can be 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 8nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 150nm, 160nm, 180nm, 200nm, 210nm, 220nm, 250nm, 260nm, 280nm, 300nm, 320nm, 350nm, 360nm, 380nm, 400nm, 440nm, 480nm, 500nm, or any two of the above values ​​as endpoints. Furthermore, the thickness of the hole transport layer is 1nm to 300nm, further 1nm to 100nm, further 5nm to 100nm, and further 1nm to 50nm.

[0275] Understandably, a tandem solar cell may simultaneously include one or more of a first charge transport layer, a second charge transport layer, a third charge transport layer, and a fourth charge transport layer.

[0276] Please refer to Figure 1. As an example, the stacked solar cell 10 includes a first electrode 210, a first charge transport layer 310, a first light absorption layer 110, a second charge transport layer 320, a connecting layer 900, a third charge transport layer 330, a second light absorption layer 120, a fourth charge transport layer 340, and a second electrode 220, which are stacked together.

[0277] Furthermore, the solar cell also includes a substrate, on which the first electrode is disposed. The substrate can be made of glass, thus forming a transparent conductive glass with the first electrode material. Examples of transparent conductive glasses include FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), and IZO (indium zinc oxide).

[0278] Understandably, solar cells, in terms of structure, include formal and inverted structures. The first electrode is a light-transmitting electrode, disposed on a substrate. The formal structure of a tandem solar cell is determined by whether the first cell is formal or inverted. If the first cell includes a first electrode, an electron transport layer, a first light-absorbing layer, and a hole transport layer stacked sequentially, then the tandem solar cell has a formal structure. If the first cell includes a first electrode, a hole transport layer, a first light-absorbing layer, and an electron transport layer stacked sequentially, then the tandem solar cell has an inverted structure.

[0279] Since the first electrode is a transparent electrode, serving as the sunlight incident side, the film layer located near the sunlight incident side of the light absorption layer in the inverted structure is the hole transport layer. Therefore, the side of the light absorption layer near the hole transport layer generates more holes due to the photovoltaic effect, resulting in a higher hole concentration in the hole transport layer. Furthermore, because the hole transport rate is slower than the electron transport rate, placing the hole transport layer near the sunlight incident side means that holes generated on the side of the light absorption layer near the hole transport layer do not need to traverse the entire light absorption layer, shortening the transport path and thus improving the hole collection rate. In addition, because the hole transport rate is slower than the electron transport rate, the inverted structure helps improve the rate matching between the hole and electron transport rates.

[0280] Please refer to Figure 1. As an example, the stacked solar cell 10 includes a substrate 800, a first electrode 210, a first charge transport layer 310, a first light absorption layer 110, a second charge transport layer 320, a connecting layer 900, a third charge transport layer 330, a second light absorption layer 120, a fourth charge transport layer 340, and a second electrode 220, which are stacked together.

[0281] As an example of a formal structure of a solar cell, please refer to Figure 1. The stacked solar cell 10 includes a substrate 800, a first electrode 210, a first charge transport layer 310, a first light absorption layer 110, a second charge transport layer 320, a connecting layer 900, a third charge transport layer 330, a second light absorption layer 120, a fourth charge transport layer 340, and a second electrode 220 stacked together. In this case, the substrate 800 and the first electrode 210 are both light-transmitting materials, the first charge transport layer 310 is an electron transport layer, and the second charge transport layer 320 is a hole transport layer.

[0282] Furthermore, if the connecting layer 900 includes a composite layer, and the tandem solar cell 10 is a two-terminal tandem solar cell, then the third charge transport layer 330 is an electron transport layer, and the fourth charge transport layer 340 is a hole transport layer.

[0283] Referring to Figure 2, further, when the connecting layer 900 includes an insulating layer, the tandem solar cell 10 is a four-terminal tandem solar cell. In this case, either the third charge transport layer 330 or the fourth charge transport layer 340 is an electron transport layer, and the other is a hole transport layer. The tandem solar cell 10 also includes a third electrode 230 and a fourth electrode 240. The third electrode 230 is disposed between the first light absorption layer 110 and the connecting layer 900; specifically, the third electrode 230 is disposed between the second charge transport layer 320 and the connecting layer 900. The fourth electrode 240 is disposed between the connecting layer 900 and the second light absorption layer 120; specifically, the fourth electrode 240 is disposed between the connecting layer 900 and the third charge transport layer 230.

[0284] As an example of an inverted structure of a solar cell, please refer to Figure 1. The solar cell 10 includes a substrate 800, a first electrode 210, a first charge transport layer 310, a first light absorption layer 110, a second charge transport layer 320, a connecting layer, a third charge transport layer 330, a second light absorption layer 120, a fourth charge transport layer 340, and a second electrode 220, all stacked together. In this case, the substrate 800 and the first electrode 210 are both light-transmitting materials, the first charge transport layer 310 is a hole transport layer, and the second charge transport layer 320 is an electron transport layer. Further, if the stacked solar cell 10 is a two-terminal stacked solar cell, then the third charge transport layer 330 is a hole transport layer, and the fourth charge transport layer 340 is an electron transport layer. Further, if the stacked solar cell 10 is a four-terminal stacked solar cell, then the third charge transport layer 330 and the fourth charge transport layer 340 can be the same or different, each independently serving as an electron transport layer or a hole transport layer.

[0285] In some embodiments, the first and second battery cells are connected via a common electrode. For example, a common fifth electrode is used, with the second electrode in the second battery cell positioned opposite to this common fifth electrode. Thus, the tandem solar cell includes a first electrode, a first light-absorbing layer, a common fifth electrode, a second light-absorbing layer, and a second electrode stacked sequentially. The fifth electrode, as the common electrode, can serve as either a positive or negative output electrode, while the first and second electrodes are electrodes with opposite polarities to the common electrode, thereby forming a three-terminal tandem solar cell. In a three-terminal tandem solar cell, the two battery cells are connected in parallel, eliminating the problem of current mismatch.

[0286] Furthermore, the thickness of the shared electrode is relatively large, but generally smaller than the combined thickness of the third and fourth electrodes in a four-terminal tandem solar cell. Therefore, the amount of electrode material used can be reduced, thereby lowering its cost to a certain extent.

[0287] Furthermore, the common electrode comprises a stacked transparent conductive oxide layer, a grid electrode layer, and another transparent conductive oxide layer. The transparent conductive oxide layer provides good light transmission, while the grid electrode layer enhances carrier collection while minimizing the light-absorbing area. Furthermore, the grid cell layer comprises metal grid lines.

[0288] In some embodiments, the first battery cell further includes a first passivation layer disposed on the side of the first light-absorbing layer facing the first electrode. Optionally, the first passivation layer is disposed on at least a portion of the surface of the first light-absorbing layer facing the first electrode. The first passivation layer can be used to passivate defects on at least a portion of the surface of the first light-absorbing layer facing the first electrode, thereby improving the stability and light absorption efficiency of the first light-absorbing layer.

[0289] In this application, "at least part of the surface" can refer to part or all of the surface, and so on below.

[0290] In some embodiments, the first battery cell further includes a second passivation layer disposed on the side of the light-absorbing layer facing the connecting layer. Optionally, the second passivation layer is disposed on at least a portion of the surface of the first light-absorbing layer facing the connecting layer. The second passivation layer can be used to passivate defects on at least a portion of the surface of the first light-absorbing layer facing the connecting layer, thereby improving the stability and light absorption efficiency of the first light-absorbing layer.

[0291] In some embodiments, the second battery cell further includes a third passivation layer disposed on the side of the second light-absorbing layer facing the connecting layer. Optionally, the third passivation layer is disposed on at least a portion of the surface of the second light-absorbing layer facing the connecting layer. The third passivation layer can be used to passivate defects on at least a portion of the surface of the second light-absorbing layer facing the connecting layer, thereby improving the stability and light absorption efficiency of the second light-absorbing layer.

[0292] In some embodiments, the second battery cell further includes a fourth passivation layer disposed on the side of the second light-absorbing layer facing the second electrode; optionally, the fourth passivation layer is disposed on at least a portion of the surface of the second light-absorbing layer facing the second electrode. The fourth passivation layer can be used to passivate defects on at least a portion of the surface of the second light-absorbing layer facing the second electrode, thereby improving the stability and light absorption efficiency of the second light-absorbing layer.

[0293] In some embodiments, the first battery cell includes a first passivation layer and a first charge transport layer, wherein the first passivation layer is disposed between the first charge transport layer and the first light absorption layer.

[0294] In some embodiments, the first battery cell includes a second passivation layer and a second charge transport layer, wherein the second passivation layer is disposed between the first light absorption layer and the second charge transport layer.

[0295] In some embodiments, the second battery cell includes a third passivation layer and a third charge transport layer, wherein the third passivation layer is disposed between the third charge transport layer and the second light absorption layer.

[0296] In some embodiments, the second battery cell includes a fourth passivation layer and a fourth charge transport layer, wherein the fourth passivation layer is disposed between the second light absorption layer and the fourth charge transport layer.

[0297] In some embodiments, the materials of the first passivation layer and the second passivation layer are used to passivate the first light-absorbing layer. The materials of the first passivation layer and / or the second passivation layer are chemically bonded to the anions or cations of the first absorber layer material. The main structure of the crystal of the first absorber layer material may generate anion or cation defects. The materials of the first passivation layer and / or the second passivation layer can chemically bond to the anions or cations at the defect sites, thereby passivating the defects, reducing nonradiative recombination of charge carriers, and improving the conversion efficiency of the solar cell.

[0298] Taking the first light-absorbing material containing perovskite material as an example, perovskite material may generate anionic vacancy defects, such as iodine vacancy defects and bromine vacancy defects, during the crystallization process, and may also generate cation vacancy defects, such as A-site cation defects. By selecting materials that can chemically bond with the anions or cations of perovskite material, the above defects can be passivated and the non-radiative recombination caused by defects can be improved.

[0299] Taking a first light-absorbing material comprising a perovskite material as an example, the materials of the first passivation layer and / or the second passivation layer may include passivating agents conventionally used in the art for passivating perovskite light-absorbing layers, such as small organic molecules, organic salts, inorganic salts, polymers, etc. Small organic molecule passivating agents include, but are not limited to, phenylethylamine, ethylenediamine, pyridine, butanethiol, 2,5-thiophene dicarboxylic acid, etc. Organic salt passivating materials include, but are not limited to, piperazine iodine, phenylethylamine hydroiodate, dodecyl hydroiodate, guanidine bromide, thiophene ethylamine hydroiodate, ethylenediamine hydroiodate, and oleylamine iodine. Inorganic salt passivating materials include, but are not limited to, zinc chloride, potassium chloride, and gallium chloride. Polymer passivating materials include, but are not limited to, polymethyl methacrylate, polyethylene oxide, polyacrylonitrile, and polyvinyl alcohol.

[0300] In some embodiments, the materials of the third and / or fourth passivation layers are chemically bonded to the anionic or cationic sites of the material of the second light-absorbing layer. Further, the materials of the third and fourth passivation layers can be used, but are not limited to, to passivate cationic or anionic sites in silver-bismuth sulfide-type materials, particularly divalent anionic sites, such as S...2- Defects at sites of oxalic elements are passivated.

[0301] In some embodiments, the thicknesses of the first passivation layer, the second passivation layer, the third passivation layer, and the fourth passivation layer may be the same or different, and each may be independently 1nm to 20nm. For example, they may be 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 8nm, 10nm, 12nm, 15nm, 16nm, 20nm, or any two of the above values ​​as endpoints.

[0302] Understandably, a tandem solar cell may include one or more of a first passivation layer, a second passivation layer, a third passivation layer, and a fourth passivation layer.

[0303] In some embodiments, the tandem solar cell includes a first electrode, an optional first passivation layer, a first light-absorbing layer, an optional second passivation layer, a connecting layer, an optional third passivation layer, a second light-absorbing layer, an optional fourth passivation layer, and a second electrode, all stacked together.

[0304] Please refer to Figure 3. As an example, the stacked solar cell 10 includes a substrate 800, a first electrode 210, a first passivation layer 410, a first light absorption layer 110, a second passivation layer 420, a connecting layer 900, a third passivation layer 430, a second light absorption layer 120, a fourth passivation layer 440, and a second electrode 220 stacked together.

[0305] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge transport layer, an optional first passivation layer, a first light absorption layer, an optional second passivation layer, an optional second charge transport layer, a connecting layer, an optional third charge transport layer, an optional third passivation layer, a second light absorption layer, an optional fourth passivation layer, an optional fourth charge transport layer, and a second electrode, all stacked together.

[0306] Please refer to Figure 4. As an example, the stacked solar cell includes a substrate 800, a first electrode 210, a first charge transport layer 310, a first passivation layer 410, a first light absorption layer 110, a second passivation layer 420, a second charge transport layer 320, a connecting layer 900, a third charge transport layer 330, a third passivation layer 430, a second light absorption layer 120, a fourth passivation layer 440, a fourth charge transport layer 340, and a second electrode 220, all stacked together.

[0307] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge transport layer, a first light absorption layer, an optional second charge transport layer, a connecting layer, an optional third charge transport layer, a second light absorption layer, an optional fourth charge transport layer, and a second electrode, all stacked together.

[0308] As an example, a tandem solar cell includes a substrate, a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together.

[0309] In some embodiments, the tandem solar cell further includes a first barrier layer disposed between the first electrode and the first light-absorbing layer.

[0310] Understandably, the barrier layer in this application is used to prevent the reverse transport of charge carriers (electrons or holes), thus avoiding carrier recombination and improving the open-circuit voltage and photoelectric conversion efficiency of the cell. In some embodiments, the tandem solar cell includes a first barrier layer and the aforementioned first charge transport layer. Further, the first barrier layer may be disposed between the first electrode and the first charge transport layer. Further, the first barrier layer may be disposed between the first charge transport layer and the first light absorption layer. Understandably, one or both of the first barrier layers may be disposed between the first electrode and the first charge transport layer and between the first charge transport layer and the first light absorption layer.

[0311] Furthermore, if the first charge transport layer described above is an electron transport layer, then the first blocking layer is a hole blocking layer. The function of the hole blocking layer is to transport electrons and block holes, thereby reducing the recombination of electrons and holes and improving the open-circuit voltage and photoelectric conversion efficiency of the battery. Further, if the first charge transport layer described above is a hole transport layer, then the first blocking layer is an electron blocking layer. The function of the electron blocking layer is to transport holes and block electrons, thereby reducing the recombination of electrons and holes and improving the open-circuit voltage and photoelectric conversion efficiency of the battery.

[0312] In some embodiments, the tandem solar cell further includes a second barrier layer disposed between the first light-absorbing layer and the connecting layer.

[0313] In some embodiments, the tandem solar cell includes a second barrier layer and the aforementioned second charge transport layer. Further, the second barrier layer may be disposed between the second charge transport layer and the connecting layer. Further, the second barrier layer may be disposed between the first light-absorbing layer and the second charge transport layer. Understandably, the second barrier layer may be disposed between the second charge transport layer and the connecting layer, and between the first light-absorbing layer and the second charge transport layer, or both.

[0314] Furthermore, if the second charge transport layer described above is an electron transport layer, then the second blocking layer is a hole blocking layer. The function of the hole blocking layer is to transport electrons and block holes, thereby reducing the recombination of electrons and holes and improving the open-circuit voltage and photoelectric conversion efficiency of the battery. Further, if the second charge transport layer described above is a hole transport layer, then the second blocking layer is an electron blocking layer. The function of the electron blocking layer is to transport holes and block electrons, thereby reducing the recombination of electrons and holes and improving the open-circuit voltage and photoelectric conversion efficiency of the battery.

[0315] Furthermore, one of the first and second barrier layers is an electron barrier layer and the other is a hole barrier layer. In some embodiments, the tandem solar cell further includes a third barrier layer disposed between the connecting layer and the second light-absorbing layer.

[0316] In some embodiments, the tandem solar cell includes a third barrier layer and the aforementioned third charge transport layer. Further, the third barrier layer is disposed between the connecting layer and the third charge transport layer. Further, the third barrier layer is disposed between the third charge transport layer and the second light-absorbing layer. Understandably, the third barrier layer may be disposed between the connecting layer and the third charge transport layer, or between the third charge transport layer and the second light-absorbing layer, or both.

[0317] Furthermore, if the aforementioned third charge transport layer is an electron transport layer, then the third blocking layer is a hole blocking layer. The function of the hole blocking layer is to transport electrons and block hole transport, thereby reducing electron-hole recombination and improving the battery's open-circuit voltage and photoelectric conversion efficiency. Further, if the aforementioned third charge transport layer is a hole transport layer, then the third blocking layer is an electron blocking layer. The function of the electron blocking layer is to transport holes and block electron transport, thereby reducing electron-hole recombination and improving the battery's open-circuit voltage and photoelectric conversion efficiency.

[0318] In some embodiments, the tandem solar cell further includes a fourth barrier layer, with the second barrier layer disposed between the second light-absorbing layer and the second electrode.

[0319] In some embodiments, the tandem solar cell includes a fourth barrier layer and the aforementioned fourth charge transport layer. Further, the fourth barrier layer is disposed between the fourth charge transport layer and the connecting layer. Further, the fourth barrier layer is disposed between the second light-absorbing layer and the fourth charge transport layer. Understandably, the fourth barrier layer may be disposed between the fourth charge transport layer and the connecting layer, and between the second light-absorbing layer and the fourth charge transport layer, or both.

[0320] Furthermore, if the aforementioned fourth charge transport layer is an electron transport layer, then the fourth blocking layer is a hole blocking layer. The function of the hole blocking layer is to transport electrons and block hole transport, thereby reducing electron-hole recombination and improving the battery's open-circuit voltage and photoelectric conversion efficiency. Further, if the aforementioned fourth charge transport layer is a hole transport layer, then the fourth blocking layer is an electron blocking layer. The function of the electron blocking layer is to transport holes and block electron transport, thereby reducing electron-hole recombination and improving the battery's open-circuit voltage and photoelectric conversion efficiency.

[0321] Furthermore, one of the third and fourth blocking layers is an electron blocking layer, and the other is a hole blocking layer.

[0322] Furthermore, if the tandem solar cell is a two-terminal tandem solar cell, then one of the second and third blocking layers is an electron blocking layer and the other is a hole blocking layer.

[0323] Furthermore, the LUMO (lowest unoccupied molecular orbital) energy level of the hole blocking layer material is lower than the conduction band bottom (CBM) of the light absorption layer material of the corresponding battery cell, and the HOMO (highest occupied molecular orbital) energy level of the hole blocking layer material is lower than the valence band top (VBM) of the light absorption layer material of the corresponding battery cell. In this way, the function of transporting electrons and blocking holes can be realized.

[0324] In this application, both the LUMO and HOMO energy levels of the material can be measured by ultraviolet photoelectron spectroscopy (UPS).

[0325] Furthermore, the hole blocking layer may be made of one or more of the following materials: 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline (BCP), SnO2, ZnO, and cerium oxide (CeOx), where x is any value between 0 and 2.

[0326] Furthermore, the thickness of the hole blocking layer is 0.5nm to 50nm, or more specifically 1nm to 50nm, 0.5nm to 20nm, or 1nm to 20nm. For example, it can be 0.5nm, 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 8nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, or any two of the above values ​​as endpoints.

[0327] Furthermore, the LUMO energy level of the electron blocking layer material is higher than the conduction band bottom (CBM) of the light absorption layer material of the corresponding battery cell, and the HOMO energy level of the electron blocking layer material is higher than the valence band top (VBM) of the light absorption layer material of the corresponding battery cell. In this way, the function of transporting holes and blocking electrons can be realized.

[0328] Further, the electron blocking layer includes, but is not limited to, one or more of molybdenum oxide, vanadium oxide, LiF, and Al2O3. Optionally, the electron blocking layer includes Al2O3. Further, the thickness of the electron blocking layer is 0.5 nm to 50 nm, more specifically 1 nm to 50 nm, 0.5 nm to 20 nm, or 1 nm to 20 nm. As an example, it can be 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, or any two of the above values ​​as endpoints.

[0329] Furthermore, the thickness of the first barrier layer and the second barrier layer may be the same or different, and each may independently range from 0.5nm to 50nm. For example, it may be 0.5nm, 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 8nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, or any two of the above values ​​as endpoints.

[0330] In some embodiments, the tandem solar cell includes a first electrode, an optional first barrier layer, an optional first charge transport layer, a first light absorption layer, an optional second charge transport layer, a connecting layer, an optional third charge transport layer, a second light absorption layer, an optional fourth charge transport layer, an optional fourth barrier layer, and a second electrode, all stacked together.

[0331] As an example, a tandem solar cell includes a substrate, a first electrode, a first barrier layer, a first charge transport layer, a first light absorption layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, a fourth barrier layer, and a second electrode, all stacked together.

[0332] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge transport layer, a first light absorption layer, an optional second charge transport layer, an optional second barrier layer, a connecting layer, an optional third barrier layer, an optional third charge transport layer, a second light absorption layer, an optional fourth charge transport layer, and a second electrode.

[0333] As an example, a tandem solar cell includes a substrate, a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a second barrier layer, a connecting layer, a third barrier layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode, all stacked together.

[0334] In some embodiments, the tandem solar cell includes a first electrode, an optional first barrier layer, an optional first charge transport layer, a first light absorption layer, an optional second charge transport layer, an optional second barrier layer, a connecting layer, an optional third barrier layer, an optional third charge transport layer, a second light absorption layer, an optional fourth charge transport layer, an optional fourth barrier layer, and a second electrode, all stacked together.

[0335] Referring to Figure 5, as an example, the stacked solar cell 10 includes a substrate 800, a first electrode 210, a first barrier layer 610, a first charge transport layer 310, a first light absorption layer 110, a second charge transport layer 320, a second barrier layer 620, a connecting layer 900, a third barrier layer 630, a third charge transport layer 330, a second light absorption layer 120, a fourth charge transport layer 340, a fourth barrier layer 640, and a second electrode 220, all stacked together.

[0336] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge transport layer, an optional first blocking layer, a first light absorbing layer, an optional second blocking layer, an optional second charge transport layer, a connecting layer, an optional third charge transport layer, an optional third blocking layer, a second light absorbing layer, an optional fourth blocking layer, an optional fourth charge transport layer, and a second electrode, all stacked together.

[0337] As an example, a tandem solar cell includes a substrate, a first electrode, a first charge transport layer, a first barrier layer, a first light absorption layer, a second barrier layer, a second charge transport layer, a connecting layer, a third charge transport layer, a third barrier layer, a second light absorption layer, a fourth barrier layer, a fourth charge transport layer, and a second electrode, all stacked together.

[0338] In some embodiments, the tandem solar cell includes a first electrode, an optional first barrier layer, an optional first charge transport layer, an optional first barrier layer, a first light absorption layer, an optional second barrier layer, an optional second charge transport layer, an optional second barrier layer, a connecting layer, an optional third barrier layer, an optional third charge transport layer, an optional third barrier layer, a second light absorption layer, an optional fourth barrier layer, an optional fourth charge transport layer, an optional fourth barrier layer, and a second electrode, all stacked together.

[0339] As an example, a stacked solar cell includes a substrate, a first electrode, a first barrier layer, a first charge transport layer, a first barrier layer, a first light absorption layer, a second barrier layer, a second charge transport layer, a second barrier layer, a connecting layer, a third barrier layer, a third charge transport layer, a third barrier layer, a second light absorption layer, a fourth barrier layer, a fourth charge transport layer, a fourth barrier layer, and a second electrode, all stacked together.

[0340] In some embodiments, the tandem solar cell includes a first electrode, an optional first barrier layer, an optional first charge transport layer, an optional first passivation layer, a first light-absorbing layer, an optional second passivation layer, an optional second charge transport layer, a connecting layer, an optional third charge transport layer, an optional third passivation layer, a second light-absorbing layer, an optional fourth passivation layer, an optional fourth charge transport layer, an optional fourth barrier layer, and a second electrode, all stacked together. Optionally, a barrier layer may be further provided at one or more locations between the first charge transport layer and the first passivation layer, between the second passivation layer and the second charge transport layer, between the third charge transport layer and the third passivation layer, and between the fourth passivation layer and the fourth charge transport layer.

[0341] As an example, a tandem solar cell includes a substrate, a first electrode, a first barrier layer, a first charge transport layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second charge transport layer, a connecting layer, a third charge transport layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth charge transport layer, a fourth barrier layer, and a second electrode, all stacked together. Optionally, a barrier layer may be further provided at one or more locations between the first charge transport layer and the first passivation layer, between the second passivation layer and the second charge transport layer, between the third charge transport layer and the third passivation layer, and between the fourth passivation layer and the fourth charge transport layer.

[0342] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge transport layer, an optional first passivation layer, a first light absorption layer, an optional second passivation layer, an optional second charge transport layer, an optional second barrier layer, a connecting layer, an optional third barrier layer, an optional third charge transport layer, an optional third passivation layer, a second light absorption layer, an optional fourth passivation layer, an optional fourth charge transport layer, and a second electrode, all stacked together.

[0343] As an example, a tandem solar cell includes a substrate, a first electrode, a first charge transport layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second charge transport layer, a second barrier layer, a connecting layer, a third barrier layer, a third charge transport layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth charge transport layer, and a second electrode, all stacked together.

[0344] In some embodiments, the tandem solar cell includes a first electrode, an optional first barrier layer, an optional first charge transport layer, an optional first passivation layer, a first light absorption layer, an optional second passivation layer, an optional second charge transport layer, an optional second barrier layer, a connecting layer, an optional third barrier layer, an optional third charge transport layer, an optional third passivation layer, a second light absorption layer, an optional fourth passivation layer, an optional fourth charge transport layer, an optional fourth barrier layer, and a second electrode, all stacked together.

[0345] As an example, a stacked solar cell includes a substrate, a first electrode, a first barrier layer, a first charge transport layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second charge transport layer, a second barrier layer, a connecting layer, a third barrier layer, a third charge transport layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth charge transport layer, a fourth barrier layer, and a second electrode, all stacked together.

[0346] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge transport layer, an optional first barrier layer, an optional first passivation layer, a first light absorption layer, an optional second passivation layer, an optional second barrier layer, an optional second charge transport layer, a connecting layer, an optional third charge transport layer, an optional third barrier layer, an optional third passivation layer, a second light absorption layer, an optional fourth passivation layer, an optional fourth barrier layer, an optional fourth charge transport layer, and a second electrode, all stacked together.

[0347] As an example, a stacked solar cell includes a substrate, a first electrode, a first charge transport layer, a first barrier layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second barrier layer, a second charge transport layer, a connecting layer, a third charge transport layer, a third barrier layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth barrier layer, a fourth charge transport layer, and a second electrode, all stacked together.

[0348] Understandably, a tandem solar cell may include one or more of a first barrier layer, a second barrier layer, a third barrier layer, and a fourth barrier layer.

[0349] In some embodiments, the solar cell further includes a first charge injection layer and a first charge transport layer, the first charge injection layer being disposed between the first electrode and the first charge transport layer.

[0350] In some embodiments, the tandem solar cell further includes a second charge injection layer and a second charge transport layer, the second charge injection layer being disposed between the connecting layer and the second charge transport layer.

[0351] In the first charge injection layer and the second charge injection layer, one is an electron injection layer and the other is a hole injection layer. If the first charge transport layer is an electron transport layer, then the first charge injection layer is also an electron injection layer. The electron injection layer promotes the efficient injection of electrons into the electron transport layer. If the first charge transport layer is a hole transport layer, then the first charge injection layer is also a hole injection layer. The hole injection layer promotes the efficient injection of holes into the hole transport layer.

[0352] In some embodiments, the solar cell further includes a third charge injection layer and a third charge transport layer, wherein the third charge injection layer is disposed between the connecting layer and the third charge transport layer.

[0353] In some embodiments, the tandem solar cell further includes a fourth charge injection layer and a fourth charge transport layer, wherein the fourth charge injection layer is disposed between the fourth charge transport layer and the second electrode.

[0354] One of the third charge injection layer and the other of the fourth charge injection layer is an electron injection layer, and the other is a hole injection layer.

[0355] As an example, the tandem solar cell further includes a third charge injection layer and a third charge transport layer. If the third charge transport layer is an electron transport layer, then the third charge injection layer is an electron injection layer. The electron injection layer facilitates the efficient injection of electrons into the electron transport layer. As an example, the tandem solar cell also includes a third charge injection layer and a third charge transport layer. If the third charge transport layer is a hole transport layer, then the third charge injection layer is a hole injection layer. The hole injection layer facilitates the efficient injection of holes into the hole transport layer.

[0356] As an example, the tandem solar cell further includes a fourth charge injection layer and a fourth charge transport layer. If the fourth charge transport layer is an electron transport layer, then the fourth charge injection layer is an electron injection layer. The electron injection layer facilitates efficient electron injection into the electron transport layer. As an example, the tandem solar cell also includes a fourth charge injection layer and a fourth charge transport layer. If the fourth charge transport layer is a hole transport layer, then the fourth charge injection layer is a hole injection layer. The hole injection layer facilitates efficient hole injection into the hole transport layer.

[0357] Furthermore, the materials of the electron injection layer include one or more of zinc oxide (ZnO), titanium oxide (TiO2), cesium fluoride (CsF), LiF, Li2O, fullerenes and their derivatives, carbon nanotubes (CNTs), and graphene.

[0358] Furthermore, the materials for the hole injection layer include, but are not limited to, tetrafluorotetracyanoquinone dimethyl ether, N,N'-bis[4-di(m-tolyl)aminophenyl]-N,N'-diphenylbenzidine, and tungsten oxide (WO3). 3-x CD2, where C is one or more of Cr or Mo; and D is one or more of O, S, Se, and Te.

[0359] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge injection layer, an optional first charge transport layer, a first light absorption layer, an optional second charge transport layer, an optional second charge injection layer, a connecting layer, an optional third charge injection layer, an optional third charge transport layer, a second light absorption layer, an optional fourth charge transport layer, an optional fourth charge injection layer, and a second electrode, all stacked together.

[0360] Referring to Figure 6, as an example, the stacked solar cell 10 includes a substrate 800, a first electrode 210, a first charge injection layer 710, a first charge transport layer 310, a first light absorption layer 110, a second charge transport layer 320, a second charge injection layer 720, a connecting layer 900, a third charge injection layer 730, a third charge transport layer 330, a second light absorption layer 120, a fourth charge transport layer 340, a fourth charge injection layer 740, and a second electrode 220, all stacked together.

[0361] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge injection layer, an optional first charge transport layer, an optional first passivation layer, a first light absorption layer, an optional second passivation layer, an optional second charge transport layer, an optional second charge injection layer, a connecting layer, an optional third charge injection layer, an optional third charge transport layer, an optional third passivation layer, a second light absorption layer, an optional fourth passivation layer, an optional fourth charge transport layer, an optional fourth charge injection layer, and a second electrode, all stacked together.

[0362] As an example, a stacked solar cell includes a substrate, a first electrode, a first charge injection layer, a first charge transport layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second charge transport layer, a second charge injection layer, a connecting layer, a third charge injection layer, a third charge transport layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth charge transport layer, a fourth charge injection layer, and a second electrode, all stacked together.

[0363] In some embodiments, the tandem solar cell includes a first electrode, an optional first charge injection layer, an optional first charge transport layer, an optional first passivation layer, a first light absorption layer, an optional second passivation layer, an optional second charge transport layer, an optional second charge injection layer, a connecting layer, an optional third charge injection layer, an optional third charge transport layer, an optional third passivation layer, a second light absorption layer, an optional fourth passivation layer, an optional fourth charge transport layer, an optional fourth charge injection layer, and a second electrode, all stacked together.

[0364] As an example, a stacked solar cell includes a substrate, a first electrode, a first charge injection layer, a first charge transport layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second charge transport layer, a second charge injection layer, a connecting layer, a third charge injection layer, a third charge transport layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth charge transport layer, a fourth charge injection layer, and a second electrode, all stacked together.

[0365] Understandably, one or more of the above-mentioned charge transport layers, passivation layers, barrier layers, and charge injection layers can be arbitrarily combined to form a combined technical solution without contradicting each other, and all of these are within the scope of the technical solution of this application.

[0366] In some embodiments, the materials of the first electrode, the second electrode, the third electrode, and the fourth electrode each independently include one or more of inorganic conductive materials, organic conductive materials, and organic-inorganic mixed conductive materials.

[0367] As an example, inorganic conductive materials include one or more of carbon materials, metallic materials and their alloys, and conductive metal oxides.

[0368] Furthermore, carbon materials include, but are not limited to, one or more of graphite, graphene, and carbon nanotubes.

[0369] Furthermore, conductive metal oxides include transparent conductive metal oxides.

[0370] Furthermore, the metallic materials and their alloys include one or more of Au (gold), Ag (silver), Cu (copper), Al (aluminum), Ni (nickel), Cr (chromium), Bi (bismuth), Pt (platinum), Mg (magnesium), Mo (molybdenum), and W (tungsten).

[0371] As examples, organic conductive materials include one or more of polyacrylic acid, polyimide (PI), polyaniline (PANI), polythiophene (PT) and its derivatives, and polypyrrole. Polythiophene (PT) and its derivatives include, but are not limited to, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS).

[0372] As described above, at least one of the first and second electrodes is a light-transmitting electrode. In some embodiments, the third and fourth electrodes are also light-transmitting electrodes.

[0373] The materials for transparent electrodes include, but are not limited to, transparent conductive metal oxides. For example, the materials for transparent electrodes may include, but are not limited to, one or more of the following transparent conductive metal oxides: FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), and IZO (indium zinc oxide).

[0374] Furthermore, the solar cell also includes a substrate, on which the first electrode is disposed. The substrate can be made of glass, thus forming a transparent conductive glass with the first electrode material. Examples of transparent conductive glasses include: FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), lanthanide-doped indium oxide, antimony-doped tin oxide, gallium zinc oxide (GZO), and indium tungsten oxide (IWO).

[0375] It is understandable that, in addition to using glass as a substrate, transparent flexible substrates can also be used for the light-transmitting electrode. Specifically, the material of the transparent flexible substrate can be, for example, an organic polymer material, which can be one or more of the following materials mixed in different proportions: polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene dinaphthalate (PEN), and polydimethylsiloxane (PDMS).

[0376] When one electrode is a transparent electrode, the other electrode can be either a transparent electrode or an opaque electrode. If the other electrode is an opaque electrode, its material includes, but is not limited to, organic materials, inorganic materials, or conductive materials that are a mixture of organic and inorganic materials in different proportions. Further, inorganic materials include metallic materials, and the corresponding electrode is a metallic electrode.

[0377] The aforementioned electrode layer, hole transport layer, electron transport layer, blocking layer, injection layer, light absorption layer, and other structural layers can be prepared using methods commonly used in the field, including but not limited to one or more of coating and deposition methods.

[0378] Furthermore, the coating method includes, but is not limited to, one or more of spin coating, spray coating, brush coating, wiping coating, screen coating, gravure coating, squeegee coating, and slot coating. Furthermore, depending on the precursor used in the coating method, it includes, but is not limited to, one or more of sol-gel and solution coating methods.

[0379] Furthermore, the deposition methods include, but are not limited to, one or more of the following: vacuum evaporation, sputtering deposition, plasma deposition, ion deposition, atomic layer deposition, and vacuum flash evaporation.

[0380] As an example, tin dioxide electron transport layers can be prepared using atomic layer deposition (ALD); organic electron transport layers such as methyl [6,6]-phenyl C61 butyrate can be prepared using vacuum evaporation.

[0381] As an example, perovskite layers can be prepared by methods such as vacuum flash evaporation (VCD), vacuum deposition, and multi-source co-evaporation; perovskite layers can also be prepared by coating methods.

[0382] As an example, a hole transport layer such as nickel oxide can be prepared by magnetron sputtering;

[0383] As an example, a metal electrode layer can be prepared by vacuum evaporation.

[0384] Solution methods include spin coating, spraying, blade coating, and slot coating, while solid deposition methods include vacuum evaporation, sputtering deposition, plasma deposition, and ion deposition.

[0385] It is understood that the structure of the tandem solar cell involved in this application is not limited to the structural layers listed above. Other functional layers, such as buffer layers, can also be introduced as needed.

[0386] In some embodiments, the stacking direction of each layer of the tandem solar cell is the thickness direction, which can be referred to as the first direction, and can also be referred to as the Y direction in Figure 7.

[0387] Referring to Figure 7, both the first and second cell units of the tandem solar cell 10 are provided with channels P1, P2, and P3. Channels P1, P2, and P3 are etched regions arranged across layers, used to divide the large-area film layer of the first or second cell unit into multiple sub-cells, and to form a series structure among the multiple sub-cells within the first or second cell unit to improve output voltage and power. P1, P2, and P3 are used to connect spaced-apart structural layers, thereby creating a pathway between the first electrode of one sub-cell and the second electrode of another sub-cell, forming a cell assembly.

[0388] Channels P1, P2, and P3 can each be independently linear etching regions, also known as etching lines. Channels P1, P2, and P3 can each be independently laser etching regions. The number of channels P1, P2, and P3 can each be one or more.

[0389] The height direction of each channel corresponds to the thickness direction Y of the tandem solar cell. The width direction of each channel corresponds to the width direction of the tandem solar cell, which can be referred to as the second direction, or the X direction in Figure 7. The length direction of each channel corresponds to the length direction of the tandem solar cell, which can be referred to as the third direction or the Z direction. In some embodiments, the Z, X, and Y directions are orthogonal to each other.

[0390] It is understandable that the height of each channel is determined by the thickness of the structural layer it divides, the width of each channel can be adjusted according to the laser scribing process, and the length of each channel can be determined according to the length of the tandem solar cell.

[0391] In some embodiments, a first cell in the tandem solar cell 10 shown in FIG7 is provided as an example to illustrate its P1 channel, P2 channel and P3 channel structure.

[0392] For a two-sided tandem solar cell, the P2 and P3 channels are formed by simultaneously scribe lines across the film layers of the first and second cell units. As an example, for a two-sided tandem solar cell, the P1 channel is first formed on the first electrode, then the first and second cell units are fabricated on the first electrode, with the P2 channel formed before the second electrode is fabricated; then, after the second electrode is formed, the P3 channel is formed.

[0393] For the four-terminal tandem solar cell, the P1, P2 and P3 channel structures of the second cell in the tandem solar cell 10 are similar, and will not be described in detail here.

[0394] The first cell includes a substrate 800, a first electrode 210, a first charge transport layer 310, a first light absorption layer 110, a second charge transport layer 320, and a third electrode 230, which are sequentially stacked along the Y direction. The solar cell 10 has a P1 channel dividing the first electrode 210, a P2 channel dividing the first charge transport layer 310, the first light absorption layer 110, and the second charge transport layer 320, and a P3 channel dividing the third electrode 230.

[0395] The P1 channel is located on the first electrode and divides the first electrode along the thickness direction Y of the tandem solar cell, so that the first electrodes of two adjacent sub-cells in the X direction are not connected to each other, thereby achieving insulation.

[0396] In this design, the P2 channel divides the light-absorbing layer along the thickness direction Y of the solar cell and exposes the first electrode. The P2 channel is filled with the material of the third electrode or other conductive material to connect the first and third electrodes of adjacent sub-cells.

[0397] In this design, the P3 channel divides the third electrode along the thickness direction Y of the solar cell, thus forming multiple sub-cells. This ensures that the third electrodes of adjacent sub-cells in the X direction are not connected, achieving insulation. The sub-cells within the solar cell can be divided and connected through these channels.

[0398] The channels in the tandem solar cell 10 divide the cell unit in the solar cell 10 into several sub-cells. Each sub-cell includes a P1 channel, a P2 channel and a P3 channel. The P1 channel, P2 channel and P3 channel in each sub-cell are arranged sequentially along the X direction.

[0399] Each sub-cell includes an active region 11 and a dead region 12 surrounded by three types of channels. The active region 11 refers to the area in a solar cell that can effectively absorb photons, generate photogenerated carriers (electrons and holes), and achieve charge separation and transport. It corresponds to the area between the directly adjacent P3 and P1 channels, where P3 and P1 are directly adjacent (no P2 channel is located between them). The dead region refers to the area in a solar cell where photoelectric conversion cannot be effectively performed; it corresponds to the area between the P1 and P3 channels located on either side of the P2 channel.

[0400] In the solar cell 10 shown in Figure 7, the P1 channel passes through the first electrode 210 and is connected to the substrate 800 and the first charge transport layer 310 at both ends, respectively; the P2 channel passes through the second charge transport layer 320, the first light absorption layer 110 and the first charge transport layer 310, and is connected to the first electrode 210 and the third electrode 230 at both ends, respectively; the P3 channel passes through the third electrode 230, the second charge transport layer 320, the first light absorption layer 110 and the first charge transport layer 310, and exposes the outer surface of the first electrode 210, wherein the outer surface of the first electrode 210 refers to the side of the first electrode 210 facing the first light absorption layer 110.

[0401] In this application, unless otherwise specified, "stacked" means that any two defined structural layers are arranged adjacent to each other and that the two adjacent structural layers can be in direct contact; it is understood that an unavoidable transition layer is allowed to be formed during the process of compositing two adjacent structural layers.

[0402] According to one embodiment of this application, a photovoltaic module is also provided, which includes the solar cell described above.

[0403] The aforementioned solar cells exhibit good stability, which can improve the stability and photoelectric conversion efficiency of photovoltaic modules.

[0404] The aforementioned photovoltaic module includes one or more of the aforementioned solar cells, which can be selected according to specific application scenarios; further, the aforementioned photovoltaic module includes multiple of the aforementioned solar cells, which are connected in series or parallel to form a solar cell. Further, the aforementioned photovoltaic module may also include a tandem cell, which includes one or more of the aforementioned solar cells.

[0405] In some embodiments, the photovoltaic module further includes a photovoltaic glass layer, an adhesive layer, and a backsheet.

[0406] The solar cell has an adhesive layer on each of its two surfaces. A backsheet is provided on the surface of one adhesive layer away from the solar cell, and a photovoltaic glass layer is provided on the surface of the other adhesive layer away from the solar cell.

[0407] The photovoltaic glass layer and backsheet are used to protect the solar cells, and they have the functions of sealing, insulation and waterproofing; the adhesive layer plays the role of bonding the photovoltaic glass layer to the solar cells and bonding the backsheet to the solar cells.

[0408] In a non-limiting sense, the photovoltaic glass layer can be made of tempered glass, the backsheet can be made of TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the adhesive layer can be made of EVA (polyethylene-polyvinyl acetate copolymer).

[0409] Furthermore, the aforementioned photovoltaic modules also include junction boxes and outer frames.

[0410] Junction boxes are used to protect the entire photovoltaic module's power generation system. They are essentially a current transfer station. When a cell short-circuits, the junction box will automatically disconnect the short-circuited cell string.

[0411] The outer frame serves to support and protect the entire photovoltaic module. The frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0412] Furthermore, silicone is used to bond and seal the connections between the frame and other parts of the photovoltaic module. The photovoltaic module can convert solar energy into electrical energy, which can then be stored in batteries or used to power loads.

[0413] In some embodiments, the photovoltaic module is a solar panel.

[0414] According to one embodiment of this application, a photovoltaic system is also provided, including the photovoltaic module described above.

[0415] Photovoltaic systems utilize the photovoltaic effect of solar cells in the aforementioned photovoltaic modules to directly convert solar radiation energy into electrical energy, exhibiting high stability and efficiency.

[0416] In some embodiments, the photovoltaic system described above is a photovoltaic power generation system.

[0417] Photovoltaic modules are the core component of a photovoltaic power generation system. The aforementioned photovoltaic system includes one or more photovoltaic modules, which can be selected according to specific application scenarios. Furthermore, when the aforementioned photovoltaic system includes multiple photovoltaic modules, the multiple photovoltaic modules form a photovoltaic array.

[0418] The aforementioned photovoltaic system can be a stand-alone photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0419] An independent photovoltaic (PV) power generation system includes a PV array, battery bank, charge controller, power electronic converter (inverter), and load. Its working principle is that solar radiation energy is first converted into electrical energy by the PV array, then converted by the power electronic converter to supply power to the load. Simultaneously, excess electrical energy is stored as chemical energy in an energy storage device after passing through the charge controller. Thus, when sunlight is insufficient, the energy stored in the battery can be converted into 220V, 50Hz AC power by the power electronic inverter, filter, and power frequency transformer to supply AC loads.

[0420] A grid-connected photovoltaic (PV) power generation system includes a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter), and system monitoring. Its working principle is that solar radiation energy is converted by the photovoltaic array, then converted into high-voltage DC by a high-frequency DC converter, and finally inverted by the power electronic inverter to output a sinusoidal alternating current to the grid that is in phase with the grid voltage.

[0421] The two photovoltaic power generation systems mentioned above each have their own characteristics and can be selected according to the specific application scenario.

[0422] One embodiment of this application provides an electrical device, including one or more of the above-described solar cells and photovoltaic modules.

[0423] In some of these embodiments, the solar cells or photovoltaic modules described above can be the power source of an electrical device or the energy storage unit of an electrical device.

[0424] Furthermore, the aforementioned electrical devices may include, but are not limited to, mobile devices such as electric vehicles, electric trains, ships, and satellites.

[0425] Figure 8 shows an example of an electrical device 20. This electrical device 20 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0426] In some embodiments, the aforementioned solar cells can be used as power generation devices for electrical devices. The type of power generation device may include, but is not limited to, integrated power generation. The location of the power generation device may include, but is not limited to, the roof of a vehicle, the back panel, etc.

[0427] One embodiment of this application provides a power generation device, including one or more of the above-described solar cells and photovoltaic modules.

[0428] Furthermore, the power generation device is a photovoltaic (PV) photovoltaic device.

[0429] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0430] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0431] Example 1

[0432] The fabrication of a two-terminal tandem solar cell includes the following steps:

[0433] 1. First electrode: Take an FTO conductive glass with a specification of 2.0*2.0cm, remove 0.35cm of FTO from each end by laser etching to expose the glass substrate; use cleaning solution, deionized water and ethanol in sequence for ultrasonic cleaning of the etched FTO conductive glass; blow the solvent off the FTO conductive glass under a nitrogen gun and put it into an ultraviolet ozone generator for further cleaning.

[0434] 2. First charge transport layer (hole transport layer): On FTO conductive glass treated with ultraviolet 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 charge transport layer with a thickness of 30 nm, and then heat-annealed at 150 °C for 10 min.

[0435] 3. First light absorption layer: 0.903-0.65 mmol FAI, 0.147-0.39 mmol FABr, 0.301-0.13 mmol CsI, 0.049-0.13 mmol CsBr, 1.204-0.78 mmol PbI2 and 0.196-0.52 mmol PbBr2 were added to 1 mL of a mixed solvent of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) (DMF to DMSO volume ratio of 4:1). The mixture was stirred at 600 rpm for 8 h on a magnetic stirrer and filtered to obtain a perovskite precursor solution.

[0436] 100 μL of the above-mentioned perovskite precursor solution was spin-coated onto the first charge transport layer. The specific spin-coating process was as follows: first, spin-coating was performed at a spin speed of 2000 rpm and an acceleration of 200 rpm / s for 10 s, then at a spin speed of 4000 rpm and an acceleration of 1000 rpm / s for 25 s. Then, 200 μL of chlorobenzene was added dropwise onto the spin-coated perovskite precursor solution. Next, the above-mentioned perovskite precursor solution was spin-coated again (spin-coating speed of 4000 rpm and spin-coating time of 15 s). Finally, the solution was transferred to a hot stage and annealed at 100°C for 15 min to form the first light absorption layer.

[0437] 4. Second charge transport layer (electron transport layer): C60 with a thickness of 20 nm is deposited as the second charge transport layer.

[0438] 5. Composite layer: First, spin-coating an ITO thin film onto the second charge transport layer. The spin-coating process involves first rotating at a low speed of 350 rpm for 9 to 2 seconds, then increasing the speed to 4000 rpm for 40 seconds, and finally placing it on a hot plate for annealing at 100°C for 10 minutes.

[0439] 6. Third charge transport layer (hole transport layer): Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was spin-coated onto the above composite layer (spin-coating speed was 4000 rpm and spin-coating time was 30 s), and then transferred to a hot stage for annealing at 150 °C for 10 min to form the third charge transport layer.

[0440] 7. Second light-absorbing layer: 0.25 mmol of AgNO3, 0.25 mmol of Bi(NO3)3·5H2O, and 0.4 mmol of thiourea were added to 1 ml of DMSO solution and stirred at 600 rpm for 2 h on a magnetic stirrer. The mixture was then filtered to obtain a silver-bismuth-sulfur precursor solution. 100 μL of the above silver-bismuth-sulfur precursor solution was spin-coated onto the above third charge transport layer. The spin-coating speed was initially 6000 rpm for 60 s, followed by annealing at 150 °C for 10 min on a hot plate to form a second light-absorbing layer with a thickness of 50 nm.

[0441] 8. Fourth charge transport layer (electron transport layer): A C60 layer with a thickness of 20 nm is deposited on the second light absorption layer to form the fourth charge transport layer.

[0442] 9. Second electrode (back electrode layer): A 100 nm thick layer of metallic copper (Cu) is deposited on the fourth charge transport layer to form the back electrode layer. A tandem solar cell with both ends is thus fabricated.

[0443] Example 2

[0444] The fabrication of a four-terminal tandem solar cell includes the following steps:

[0445] The method is basically the same as in Example 1, except that the material used to prepare the (6) connecting layer is different; the (6) connecting layer is an insulating layer. The insulating layer is transparent glass. In addition, the method includes the step of transferring the insulating layer into the magnetron sputtering chamber and depositing a layer of ITO on each of the two opposite surfaces of the insulating layer.

[0446] The ITO on both sides of the insulating layer serves as the third and fourth electrodes, respectively.

[0447] The photoelectric conversion efficiency and stability performance of the tandem solar cell device were tested.

[0448] (1) The photoelectric conversion efficiency of the tandem solar cell device was tested. The test method was as follows:

[0449] Using Keithley 2400SMU, AM1.5G solar irradiation at 100mW / cm 2 Under a specific light source, the battery performance was tested to obtain the photoelectric conversion efficiency (PCE). The PCE is calculated using the following parameters: PCE = Pout / Popt = Voc × Jsc × (Vmpp × Jmpp) / (Voc × Jsc) / Popt = Voc × Jsc × FF / Popt

[0450] Where Pout, Popp, Vmpp, Jmpp, Voc, and Jsc represent the battery's operating output power, incident light power, battery's maximum power point voltage, battery's maximum power point current, open-circuit voltage, and short-circuit current, respectively. FF is the fill factor.

[0451] (2) The stability of the tandem solar cell device was tested. The test method was as follows:

[0452] The tandem solar cells were placed at 65℃ and 100mW / cm². 2 Under continuous illumination by a light source, the photoelectric conversion efficiency is tracked as the aging time increases. The time required for the photoelectric conversion efficiency to decay to 80% of the initial efficiency is denoted as T80. The magnitude of this parameter indicates the stability of the tandem solar cell.

[0453] The tandem solar cell prepared in the above embodiments includes the silver bismuth sulfide material thin film AgBiS2. Because the silver bismuth sulfide material has good thermal stability and the tandem solar cell can effectively utilize solar energy, the tandem solar cell can have good device stability during long-term operation and provide good photoelectric conversion efficiency.

[0454] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0455] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the scope of the claims.

Claims

1. A tandem solar cell, comprising: The first battery cell includes a first light-absorbing layer; The second battery cell includes a second light-absorbing layer, which includes a silver bismuth sulfide type material. and, A connecting layer is disposed between the first battery cell and the second battery cell, and connects the first battery cell and the second battery cell; The band gap of the first light absorption layer is larger than that of the second light absorption layer.

2. The tandem solar cell as described in claim 1, wherein, The silver-bismuth sulfide type material includes one or more of the cubic rock salt phase crystal form and the hexagonal phase crystal form.

3. The tandem solar cell according to any one of claims 1 to 2, wherein, The grain size of the silver bismuth sulfide type material is ≥10nm, which can be selected as 10nm~10μm, or more preferably 10nm~500nm or 50nm~200nm.

4. The solar cell according to any one of claims 1 to 3, wherein, The silver bismuth sulfide type material includes one or both of polycrystalline and monocrystalline forms.

5. The tandem solar cell according to any one of claims 1 to 4, wherein, The band gap of the silver-bismuth sulfide type material is 0.8eV to 1.4eV, preferably 0.8eV to 1.2eV, and more preferably 0.9eV to 1.1eV.

6. The tandem solar cell according to any one of claims 1 to 5, wherein, The band gap of the first light absorption layer is 1.5eV to 1.9eV, and can be selected as 1.53eV to 1.65eV.

7. The tandem solar cell according to any one of claims 1 to 6, wherein, The thickness of the first light-absorbing layer is 200nm to 1000nm, and can be selected as 400nm to 600nm.

8. The tandem solar cell according to any one of claims 1 to 7, wherein, The thickness of the second light-absorbing layer is 10nm to 20μm, and can be selected as 10nm to 10μm; more preferably, it can be 30nm to 500nm or 50nm to 200nm.

9. The tandem solar cell according to any one of claims 1 to 8, wherein, The stacked solar cell includes: First electrode and second electrode; The first battery cell includes a first electrode, which is disposed on the side of the first light-absorbing layer away from the connecting layer. The second battery cell includes a second electrode, which is disposed on the side of the second light-absorbing layer away from the connecting layer.

10. The tandem solar cell of claim 9, wherein, The first battery cell further includes one or both of a first charge transport layer and a second charge transport layer; The first charge transport layer is located between the first electrode and the first light absorption layer; The second charge transport layer is located between the first light absorption layer and the connecting layer; In this configuration, one of the first charge transport layer and the other of the second charge transport layer is an electron transport layer, and the other is a hole transport layer.

11. The tandem solar cell according to any one of claims 9 to 10, wherein, The second battery cell further includes one or both of a third charge transport layer and a fourth charge transport layer; The third charge transport layer is located between the connecting layer and the second light absorption layer; The fourth charge transport layer is located between the second light absorption layer and the second electrode; Among them, one of the third charge transport layer and the other of the fourth charge transport layer is an electron transport layer and the other is a hole transport layer.

12. The tandem solar cell according to any one of claims 10 to 11, wherein, The electron transport layer comprises one or more of the following materials and their derivatives, dopants, and passivated materials: [6,6]-phenyl C61 butyrate methyl ester, [6,6]-phenyl C71 butyrate methyl ester, fullerene C61, fullerene C60, fullerene C70, tin dioxide, zinc oxide, perylene imide materials and naphthalene imide materials.

13. The tandem solar cell according to any one of claims 10 to 12, wherein, The thickness of the electron transport layer is 1 nm to 300 nm, and can be selected as 1 nm to 100 nm.

14. The tandem solar cell according to any one of claims 10 to 13, wherein, The hole transport layer comprises one or more of the following materials and their derivatives, dopants, and passivated materials: Nickel oxide, molybdenum oxide, molybdenum sulfide, cuprous oxide, cuprous iodide, cuprous thiocyanate, 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, poly-3-hexylthiophene, methoxytriphenylamine-fluoroformamidinium, triphenylamine with a triphenylene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-4-anilinecarbazole-spirobifluorene, polythiophene, and self-assembled monomolecule materials.

15. The tandem solar cell according to any one of claims 10 to 14, wherein, The thickness of the hole transport layer is 1nm to 500nm, and can be selected as 1nm to 300nm or 1nm to 100nm.

16. The tandem solar cell according to any one of claims 9 to 15, wherein, One or more of the following conditions must be met: (1) The first battery cell further includes a first passivation layer, which is disposed on the side of the first light absorption layer facing the first electrode. Optionally, the first passivation layer is disposed on at least a portion of the surface of the first light absorption layer facing the first electrode. (2) The first battery cell further includes a second passivation layer, which is disposed on the side of the first light-absorbing layer facing the connecting layer. Optionally, the second passivation layer is disposed on at least a portion of the surface of the first light-absorbing layer facing the connecting layer. (3) The second battery cell further includes a third passivation layer, which is disposed on the second light-absorbing layer. Optionally, on the side facing the connecting layer, the third passivation layer is disposed on at least a portion of the surface of the second light-absorbing layer facing the connecting layer; (4) The second battery cell further includes a fourth passivation layer, which is disposed on the side of the second light absorption layer facing the second electrode. Optionally, the fourth passivation layer is disposed on at least a portion of the surface of the second light absorption layer facing the second electrode.

17. The tandem solar cell according to any one of claims 9 to 16, wherein, One or more of the following conditions must be met: (1) The first battery cell includes a first passivation layer and a first charge transport layer, wherein the first passivation layer is disposed between the first charge transport layer and the first light absorption layer; (2) The first battery cell includes a second passivation layer and a second charge transport layer, wherein the second passivation layer is disposed between the first light absorption layer and the second charge transport layer; (3) The second battery cell includes a third passivation layer and a third charge transport layer, wherein the third passivation layer is disposed between the third charge transport layer and the second light absorption layer; (4) The second battery cell includes a fourth passivation layer and a fourth charge transport layer, wherein the fourth passivation layer is disposed between the second light absorption layer and the fourth charge transport layer.

18. The tandem solar cell as claimed in claim 16 or 17, wherein, One or more of the following conditions must be met: (1) The first battery cell includes a first passivation layer, the thickness of which is 1 nm to 20 nm; (2) The first battery cell includes a second passivation layer, the thickness of which is 1 nm to 20 nm; (3) The second battery cell includes a third passivation layer, the thickness of which is 1 nm to 20 nm; (4) The second battery cell includes a fourth passivation layer, the thickness of which is 1 nm to 20 nm.

19. The tandem solar cell according to any one of claims 16 to 18, wherein, The material in the first passivation layer and / or the second passivation layer is chemically bonded to the anionic or cationic material of the first light-absorbing layer; And / or, The material in the third passivation layer and / or the fourth passivation layer is chemically bonded to the anionic or cationic material of the second light-absorbing layer.

20. The tandem solar cell according to any one of claims 17 to 19, wherein, One or more of the following conditions must be met: (1) The first battery cell further includes a first barrier layer, which is disposed between the first electrode and the first light-absorbing layer; (2) The first battery cell further includes a second barrier layer, which is disposed between the first light-absorbing layer and the connecting layer; (3) The second battery cell further includes a third barrier layer, the third barrier layer being disposed on the connecting layer and the... Between the second light-absorbing layers; (4) The second battery cell further includes a fourth barrier layer, which is disposed between the second light-absorbing layer and the second electrode; Among them, one of the first blocking layer and the second blocking layer is an electron blocking layer and the other is a hole blocking layer; One of the third and fourth blocking layers is an electron blocking layer, and the other is a hole blocking layer.

21. The tandem solar cell of claim 20, wherein, One or more of the following conditions must be met: (1) The first battery cell includes a first barrier layer and a first charge transport layer; optionally, the first barrier layer is disposed between the first electrode and the first charge transport layer; optionally, the first barrier layer is disposed between the first charge transport layer and the first light absorption layer. (2) The first battery cell further includes a second barrier layer and a second charge transport layer; optionally, the second barrier layer is disposed between the second charge transport layer and the connecting layer; optionally, the second barrier layer is disposed between the first light absorption layer and the second charge transport layer; (3) The second battery cell further includes a third barrier layer and a third charge transport layer; optionally, the third barrier layer is disposed between the connecting layer and the third charge transport layer; optionally, the third barrier layer is disposed between the third charge transport layer and the second light absorption layer; (4) The second battery cell further includes a fourth barrier layer and a fourth charge transport layer; optionally, the fourth barrier layer is disposed between the fourth charge transport layer and the connecting layer; optionally, the fourth barrier layer is disposed between the second light absorption layer and the fourth charge transport layer.

22. The tandem solar cell according to any one of claims 20 to 21, wherein, The LUMO energy level of the hole blocking layer material is lower than the conduction band bottom (CBM) of the light absorption layer material of the corresponding battery cell, and the HOMO energy level of the hole blocking layer material is lower than the valence band top (VBM) of the light absorption layer material of the corresponding battery cell. Optionally, the hole-blocking layer comprises one or more of 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline, SnO2, ZnO, and cerium oxide.

23. The tandem solar cell according to any one of claims 20 to 22, wherein, The LUMO energy level of the electron blocking layer material is higher than the conduction band bottom CBM of the light absorption layer material of the corresponding battery cell, and the HOMO energy level of the electron blocking layer material is higher than the valence band top VBM of the light absorption layer material of the corresponding battery cell. Optionally, the electron blocking layer comprises one or more of molybdenum oxide, vanadium oxide, LiF, and Al2O3.

24. The tandem solar cell according to any one of claims 20 to 23, wherein, The thickness of the first barrier layer and the second barrier layer are each independently 0.5 nm to 50 nm.

25. The tandem solar cell according to any one of claims 9 to 24, wherein, The stacked solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together. Optionally, the stacked solar cell includes a first electrode, a first barrier layer, a first charge transport layer, a first passivation layer, a first light absorption layer, a second passivation layer, a second charge transport layer, a connecting layer, a third charge transport layer, a third passivation layer, a second light absorption layer, a fourth passivation layer, a fourth charge transport layer, a fourth barrier layer, and a second electrode, all stacked together.

26. The tandem solar cell according to any one of claims 9 to 25, wherein, The materials of the first electrode and the second electrode each independently include one or more of organic conductive materials, inorganic conductive materials, and organic-inorganic mixed conductive materials.

27. The tandem solar cell of claim 26, wherein, One or more of the following conditions must be met: (1) The inorganic conductive material includes one or more of carbon materials, metallic materials and their alloys, and transparent conductive metal oxides; (2) The organic conductive material includes one or more of polyacrylic acid, polyimide, polyaniline, polythiophene and its derivatives and polypyrrole.

28. The tandem solar cell according to any one of claims 9 to 27, wherein, At least one of the first electrode and the second electrode is a light-transmitting electrode.

29. The tandem solar cell according to any one of claims 9 to 28, wherein, The stacked solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together. The band gap of the first light-absorbing layer is larger than that of the second light-absorbing layer, and the first electrode is a light-transmitting electrode; Wherein, the first charge transport layer is an electron transport layer and the second charge transport layer is a hole transport layer; or, the first charge transport layer is a hole transport layer and the second charge transport layer is an electron transport layer.

30. The tandem solar cell according to any one of claims 25 or 29, wherein, The connecting layer includes a composite layer; Wherein, the first charge transport layer and the third charge transport layer are electron transport layers, and the second charge transport layer and the fourth charge transport layer are hole transport layers; or, the first charge transport layer and the third charge transport layer are hole transport layers, and the second charge transport layer and the fourth charge transport layer are electron transport layers.

31. The tandem solar cell of claim 30, wherein, The composite layer is made of one or more of the following materials: metal, transparent conductive oxide, and carbon.

32. The tandem solar cell of claim 31, wherein, One or more of the following conditions must be met: (1) The metallic material includes one or more of gold, copper, silver, platinum, aluminum and iron; (2) The components of the transparent conductive oxide layer include one or more of FTO, ITO, AZO, BZO, IZO, IGZO and ATO.

33. The tandem solar cell according to any one of claims 30 to 32, wherein, The thickness of the composite layer is 0.1 nm to 200 nm, and can be selected as 0.5 nm to 10 nm.

34. The tandem solar cell according to any one of claims 9 to 29, wherein, The stacked solar cell further includes a third electrode and a fourth electrode, the connecting layer includes an insulating layer, the third electrode is disposed between the first light-absorbing layer and the connecting layer, and the fourth electrode is disposed between the connecting layer and the second light-absorbing layer; Optionally, the third electrode and the fourth electrode are light-transmitting electrodes; Optionally, the first electrode and the second electrode are light-transmitting electrodes; Optionally, the stacked solar cell includes a first electrode, a first charge transport layer, a first light absorption layer, a second charge transport layer, a third electrode, a connecting layer, a fourth electrode, a third charge transport layer, a second light absorption layer, a fourth charge transport layer, and a second electrode stacked together; more preferably, one of the first charge transport layer and the second charge transport layer is an electron transport layer and the other is a hole transport layer; one of the third charge transport layer and the fourth charge transport layer is an electron transport layer and the other is a hole transport layer.

35. The tandem solar cell according to any one of claims 9 to 29, wherein, The stacked solar cell includes a first electrode, a first light-absorbing layer, a common fifth electrode, a second light-absorbing layer, and a second electrode stacked in sequence.

36. The tandem solar cell according to any one of claims 1 to 35, wherein, The chemical formula of the silver bismuth sulfide type material is MX, where M is a cation and X is an anion; optionally, X includes one or more divalent anions; optionally, M includes one or more cations.

37. The tandem solar cell of claim 36, wherein, The divalent anion includes one or more of divalent inorganic anions and divalent organic anions.

38. The tandem solar cell of claim 37, wherein, The divalent inorganic anions include O 2- S 2- Se 2- and Te 2- One or more of the following; optionally including S 2- .

39. The tandem solar cell according to any one of claims 36 to 38, wherein, M includes one or more of metal cations and organic cations; Optionally, the metal cation includes Ag. + Li + Na + K + 、Rb + Cs + Cu + Ni 2+ Cu 2+ Zn 2+ Co 2+ Bi 3+ Ga 3+ In 3+ Sb 3+ Al 3+ 、Tl 3+ and Co 3+ One or more of the following; Optionally, the organic cation includes at least one of organic amine ions, formamidinium ions, and imidazole ions.

40. The tandem solar cell of claim 36, wherein, M includes a first cation A and a second cation B, which have different elemental types; Optionally, the first cation A and the second cation B each independently comprise Ag. + Li + Na + K + 、Rb + Cs + Cu + Ni 2+ Cu 2+ Zn 2+ Co 2+ Bi 3+ Ga 3+ In 3+ Sb 3+ Al 3+ 、Tl 3+ and Co 3+ One or more of the following; Optionally, the first cation A includes Ag. + Li + Na + K + 、Rb + and Cs + One or more of the following; Optionally, the second cation B comprises Bi. 3+ .

41. The tandem solar cell of claim 40, wherein, The silver-bismuth sulfide type material includes materials with the chemical formula A. x B y Compounds of X2, where the values ​​of x and y make A x B y The compounds of X2 are electrically neutral as a whole.

42. The tandem solar cell according to any one of claims 40 to 41, wherein, The silver bismuth sulfide type material includes a compound with the chemical formula ABX2, wherein the first cation A is a monovalent cation, the second cation B is a trivalent cation, and X is a divalent anion.

43. The tandem solar cell of claim 36, wherein, The silver-bismuth sulfide type material includes materials with the chemical formula A. x B y X' z X” 2-z The compound X includes divalent anions X' and X'', where z is 0 to 2.

44. The tandem solar cell of claim 43, wherein, The silver bismuth sulfide type material includes materials with the chemical formula ABX' z X” 2-z The compound has the first cation A being a monovalent cation, the second cation B being a trivalent cation, and X comprising divalent anions X' and X'', with z ranging from 0 to 2.

45. The tandem solar cell as claimed in claim 43 or 44, wherein, One or more of the following conditions must be met: (1) The divalent anion X' and the divalent anion X” have different element types; (2) X' is S 2- z is not 0; (3) X” is selected from O 2- Se 2- and Te 2- One or more of them.

46. ​​The tandem solar cell according to any one of claims 1 to 45, wherein, The silver-bismuth sulfide type material includes AgBiS2 and AgBiS. z O 2-z AgBiS z Se 2-z AgBiS z Te 2-z One or more of the following, where z is 0 to 2.

47. The tandem solar cell according to any one of claims 1 to 46, wherein, The first light-absorbing layer comprises one or more semiconductor materials selected from perovskite, silver bismuth sulfide, crystalline silicon, copper indium gallium selenide, cadmium telluride, copper zinc tin sulfide, and gallium arsenide; optionally, the first light-absorbing layer comprises perovskite material.

48. The tandem solar cell of claim 47, wherein, The perovskite material includes one or more of compounds with the chemical formula A'B'Y3 and compounds with the chemical formula A'2CDY6; Among them, A' includes monovalent cations, B' includes divalent cations, C includes monovalent cations, D includes trivalent cations, and Y includes monovalent anions; Optionally, A' is a monovalent cation, B' is a divalent cation, C is a monovalent cation, D is a trivalent cation, and Y is a monovalent anion.

49. The tandem solar cell of claim 48, wherein, It meets one or more of the following characteristics: (1) A' includes one or more of monovalent metal cations and monovalent organic cations; (2) B' includes one or more of divalent metal cations and divalent organic cations; (3) C includes one or more of monovalent metal cations and monovalent organic cations; (4) D includes one or more of trivalent metal cations and trivalent organic cations; (5) Y includes one or more of monovalent inorganic anions and monovalent organic anions.

50. The tandem solar cell of claim 49, wherein, It meets one or more of the following characteristics: (1) The monovalent metal cation in A' includes Li + Na + K + 、Rb + and Cs + One or more of the following, wherein the monovalent organic cation includes one or more of organic amine ions, formamidin ions, and imidazole ions; (2) The divalent metal cations in B' include one or more of the following divalent cations: lead, tin, zinc, titanium, nickel, iron, cobalt, copper, gallium, germanium, beryllium, magnesium, calcium, strontium, barium, indium, manganese, chromium, molybdenum and europium; (3) The monovalent metal cation in C includes Cs + Ag + K + and Rb + One or more; (4) The trivalent metal cations in D include Bi 3+ Ni 3+ Fe 3+ Sb 3+ In 3+ and Cu 3+ One or more of the following; (5) Y includes one or more of halide ions and halide-like ions; optionally, Y includes F - Cl - ,Br - I - CN - CH3COO - SCN - BF4 - SeCN - PF6 - One or more of them.

51. A photovoltaic module comprising a tandem solar cell according to any one of claims 1 to 50.

52. A photovoltaic system comprising one or more of the tandem solar cells according to any one of claims 1 to 50 and the photovoltaic module according to claim 51.

53. An electrical device comprising one or more of the tandem solar cells according to any one of claims 1 to 50 and the photovoltaic module according to claim 51.

54. A power generation device comprising one or more of the tandem solar cells according to any one of claims 1 to 50 and the photovoltaic module according to claim 51.

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