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

Stacked solar cell, photovoltaic module, photovoltaic system, power consuming device and power generating device TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic technology, and in particular to a stacked solar cell, a photovoltaic module, a photovoltaic system, a power consuming device and a power generating device. BACKGROUND

[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, that is, when sunlight or other light sources irradiate the semiconductor material of a photovoltaic device, the energy of the photons is absorbed by the semiconductor to excite electron-hole pairs. Under the action of the electric field inside the semiconductor, the electrons and holes move in different directions, thereby forming a potential difference between the two ends of the device, and when an external circuit is connected, an electric current can be generated.

[0003] Compared with a single-junction solar cell, a stacked solar cell includes a plurality of different band gap semiconductor materials stacked together, forming a plurality of p-n junctions. The working principle is that different band gap materials can absorb different wavelengths of sunlight, thereby more effectively utilizing sunlight and achieving higher photon capture. The plurality of p-n junctions work together to improve the open-circuit voltage and short-circuit current of the cell, thereby improving the conversion efficiency.

[0004] However, the service life of a conventional stacked solar cell is still relatively low, and how to prolong the service life of a stacked solar cell is one of the key problems to be solved.

[0005] SUMMARY

[0006] To achieve the above-mentioned purpose, the present application provides a stacked solar cell, a photovoltaic module, a photovoltaic system, a power consuming device and a power generating device, which have a relatively long service life.

[0007] In a first aspect, the present application provides a stacked solar cell, comprising:

[0008] a first cell unit comprising a first light absorbing layer;

[0009] a second cell unit comprising a second light absorbing layer, the second light absorbing layer comprising a silver bismuth sulfide mineral type material; and

[0010] a connecting layer arranged between the first cell unit and the second cell unit and connecting the first cell unit and the second cell unit;

[0011] wherein the band gap of the first light absorbing layer is greater than the band gap of the second light absorbing layer.

[0012] Silver bismuth sulfide mineral type material is a kind of semiconductor material, which has light absorption and high light absorption coefficient, and can be used as a light-sensitive material to absorb light energy. The silver bismuth sulfide mineral type material has good stability and can replace the narrow band gap light absorption layer with poor stability in the stacked battery as the light absorption layer of the narrow band gap battery. Therefore, the stacked solar cell containing the silver bismuth sulfide mineral type material, the first battery unit being a wide band gap battery unit and the second battery unit being a narrow band gap battery unit, can absorb a wider spectrum range, effectively utilize solar energy, and has higher stability of the narrow band gap battery unit. Therefore, the stacked solar cell has good device stability and provides good photoelectric conversion efficiency during long-term operation.

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

[0014] In some embodiments, the silver bismuth sulfide mineral type material has a grain size of ≥10 nm, optionally 10 nm-10 μm, more optionally 10 nm-500 nm or 50 nm-200 nm.

[0015] In some embodiments, the silver bismuth sulfide mineral type material includes one or both of polycrystal and single crystal.

[0016] In some embodiments, the silver bismuth sulfide mineral type material has a band gap of 0.8 eV-1.4 eV, optionally 0.8 eV-1.2 eV, more optionally 0.9 eV-1.1 eV. The silver bismuth sulfide mineral type material has a band gap in the above range, which is a good narrow band gap light absorption material with high absorption coefficient, suitable band gap, good charge transport performance, and good material stability. The thin film of the silver bismuth sulfide mineral type material can achieve high current density in a small thickness range.

[0017] In some embodiments, the first light absorption layer has a band gap of 1.5 eV-1.9 eV, optionally 1.53 eV-1.65 eV. In this way, long-wavelength and short-wavelength light can be effectively absorbed, thereby improving photoelectric conversion efficiency.

[0018] In some embodiments, the first light absorption layer has a thickness of 200 nm-1000 nm, optionally 400 nm-600 nm.

[0019] In some embodiments, the second light absorption layer has a thickness of 10 nm-20 μm, optionally 10 nm-10 μm, more optionally 30 nm-500 nm or 50 nm-200 nm.

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

[0021] a first electrode and a second electrode;

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

[0023] In some embodiments, the first 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 absorbing layer;

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

[0026] wherein 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.

[0027] In some embodiments, the second 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 absorbing layer;

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

[0030] wherein 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.

[0031] In this way, the efficiency of charge transport and extraction of the cell can be improved by the provision of the charge transport layers.

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

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

[0034] In some embodiments, the electron transport layer has a thickness of 1 nm to 300 nm, optionally 1 nm to 100 nm.

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

[0036] Nickel oxide, molybdenum oxide, molybdenum sulfide, cuprous oxide, cuprous iodide, cuprous thiocyanate, 2,2',7,7'-tetrakis(N,N-p-methoxyphenylamine)-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, poly-3-hexylthiophene, methoxyphenylamine-fluoroformamidine, triphenylamine with a core of triptycene, 3,4-ethylenedioxythiophene-methoxyphenylamine, N-4-aniline carbazole-spirofluorene, polythiophene and self-assembled monomolecular material.

[0037] In some embodiments, the thickness of the hole transport layer is 1 nm to 500 nm, optionally 1 nm to 300 nm or 1 nm to 100 nm.

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

[0039] (1) The first battery unit further comprises a first passivation layer, which is arranged on the side of the first light absorbing layer facing the first electrode, and optionally, the first passivation layer is arranged on at least part of the surface of the first light absorbing layer facing the first electrode;

[0040] (2) The first battery unit further comprises a second passivation layer, which is arranged on the side of the first light absorbing layer facing the connecting layer, and optionally, the second passivation layer is arranged on at least part of the surface of the first light absorbing layer facing the connecting layer;

[0041] (3) The second battery unit further comprises a third passivation layer, which is arranged on the side of the second light absorbing layer facing the connecting layer, and optionally, the third passivation layer is arranged on at least part of the surface of the second light absorbing layer facing the connecting layer;

[0042] (4) The second battery unit further comprises a fourth passivation layer, which is arranged on the side of the second light absorbing layer facing the second electrode, and optionally, the fourth passivation layer is arranged on at least part of the surface of the second light absorbing layer facing the second electrode.

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

[0044] (1) The first battery unit comprises a first passivation layer and a first charge transport layer, and the first passivation layer is arranged between the first charge transport layer and the first light absorbing layer;

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

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

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

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

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

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

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

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

[0053] In some embodiments, the material in the first passivation layer and / or the second passivation layer is anionically or cationically chemically 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 anionically or cationically chemically bonded to the material of the second light absorbing layer.

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

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

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

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

[0059] (4) the second battery cell further comprises a fourth barrier layer, the fourth barrier layer is disposed between the second photo-absorption layer and the second electrode;

[0060] wherein one of the first barrier layer and the second barrier layer is an electron barrier layer, and the other is a hole barrier layer;

[0061] one of the third barrier layer and the fourth barrier layer is an electron barrier layer, and the other is a hole barrier layer.

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

[0063] (1) the first battery cell comprises 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 photo-absorption layer;

[0064] (2) the first battery cell further comprises 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 photo-absorption layer and the second charge transport layer;

[0065] (3) the second battery cell further comprises 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 photo-absorption layer;

[0066] (4) the second battery cell further comprises 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 photo-absorption layer and the fourth charge transport layer.

[0067] In some embodiments, the LUMO energy level of the material of the hole barrier layer is lower than the CBM of the material of the photo-absorption layer of the corresponding battery cell, and the HOMO energy level of the material of the hole barrier layer is lower than the VBM of the material of the photo-absorption layer of the corresponding battery cell;

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

[0069] In some embodiments, the LUMO energy level of the material of the electron blocking layer is higher than the CBM of the material of the light absorbing layer of the corresponding cell, and the HOMO energy level of the material of the electron blocking layer is higher than the VBM of the material of the light absorbing layer of the corresponding cell.

[0070] Optionally, the electron blocking layer comprises one or more of molybdenum oxide, vanadium oxide, LiF and AI2O3.

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

[0072] In some embodiments, the tandem solar cell comprises the first electrode, a first charge transport layer, the first light absorbing layer, a second charge transport layer, the connecting layer, a third charge transport layer, the second light absorbing layer, a fourth charge transport layer and the second electrode arranged in a stack.

[0073] Optionally, the tandem solar cell comprises the first electrode, a first blocking layer, a first charge transport layer, a first passivation layer, the first light absorbing layer, a second passivation layer, a second charge transport layer, the connecting layer, a third charge transport layer, a third passivation layer, the second light absorbing layer, a fourth passivation layer, a fourth charge transport layer, a fourth blocking layer and the second electrode arranged in a stack.

[0074] In some embodiments, the material of each of the first electrode and the second electrode independently comprises one or more of an organic conductive material, an inorganic conductive material and an organic-inorganic hybrid conductive material.

[0075] In some embodiments, one or more of the following conditions is satisfied:

[0076] (1) the inorganic conductive material comprises one or more of a carbon material, a metal material and alloys thereof, and a transparent conductive metal oxide;

[0077] (2) the organic conductive material comprises one or more of polyacrylic acid, polyimide, polyaniline, polythiophene and derivatives thereof, 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 tandem solar cell comprises the first electrode, a first charge transport layer, the first light absorbing layer, a second charge transport layer, the connecting layer, a third charge transport layer, the second light absorbing layer, a fourth charge transport layer and the second electrode arranged in a stack.

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

[0081] 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 connecting layer comprises a composite layer.

[0083] The first and third charge transport layers are electron transport layers, and the second and fourth charge transport layers are hole transport layers; or the first and third charge transport layers are hole transport layers, and the second and fourth charge transport layers 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, are recombined in the composite layer, thereby achieving circuit connection of the two cells. The connecting layer comprises a composite layer, and the preparation of the stacked solar cell is simple, which can directly deposit the top cell on the bottom cell to form a single complete cell with two electrodes, thereby forming a two-terminal stacked solar cell.

[0085] In some embodiments, the material of the composite layer comprises one or more of a metal material and a transparent conductive oxide.

[0086] In some embodiments, one or more of the following conditions is satisfied:

[0087] (1) The metal material comprises one or more of gold, copper, silver, platinum, aluminum, and iron.

[0088] (2) The component of the transparent conductive oxide layer comprises 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 can be 0.5 nm to 10 nm.

[0090] In some embodiments, the stacked solar cell further comprises a third electrode and a fourth electrode, the connecting layer comprises an insulating layer, the third electrode is arranged between the first light-absorbing layer and the connecting layer, and the fourth electrode is arranged 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 comprises the first electrode, the first charge transport layer, the first light absorption layer, the second charge transport layer, the third electrode, the connecting layer, the fourth electrode, the third charge transport layer, the second light absorption layer, the fourth charge transport layer and the second electrode which are sequentially stacked. More optionally, 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] The connecting layer containing the insulating layer thus electrically isolates the first cell unit and the second cell unit, and the two cell units each have two electrodes, a total of four electrodes, and the circuits of the two cell units are independent of each other, forming a four-terminal stacked solar cell. The four-terminal stacked solar cell has lower requirements for the current and voltage matching of the cell units, because each cell unit works independently and does not need to be accurately matched in current and voltage like the two-terminal stacked solar cell. The four-terminal stacked solar cell can more flexibly select different types and performance of cell units for combination to adapt to different application scenarios and needs, and to some extent, reduces the performance loss caused by the mutual influence between the cell units.

[0095] Further, in order to further increase the light energy utilization rate of the stacked solar cell and enable the remaining solar energy after being absorbed by the previous cell unit to enter the next cell unit, the third electrode and the fourth electrode can also be set as light-transmitting electrodes.

[0096] In some embodiments, the stacked solar cell comprises a first electrode, a first light absorption layer, a shared fifth electrode, a second light absorption layer and a second electrode which are sequentially stacked. The fifth electrode can be used as a positive electrode or a negative electrode output as a shared electrode, and the first electrode and the second electrode are electrodes with opposite polarity to the shared fifth electrode, thus forming a three-terminal stacked solar cell. The two cell units in the three-terminal stacked solar cell are connected in parallel, and there is no problem of current mismatch.

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

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

[0099] In some embodiments, the divalent inorganic anion comprises one or more of O 2- , S 2- , Se 2- , and Te 2- ; optionally comprising S 2- .

[0100] In some embodiments, M comprises one or more of a metal cation and an organic cation;

[0101] Optionally, the metal cation comprises one or more of 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+ .

[0102] Optionally, the organic cation comprises at least one of an organic amine ion, a formamidinium ion, and an imidazolium ion.

[0103] In some embodiments, M comprises a first cation A and a second cation B that are different in elemental identity;

[0104] Optionally, the first cation A and the second cation B each independently comprise one or more of 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+ Co 3+ ; and one or more of

[0105] Optionally, the first cation A comprises Ag + Li + Na + K + Rb + Cs + ; and one or more of

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

[0107] In some embodiments, the silver bismuth sulfide mineral type material comprises a compound of formula A x B y X2, where x and y are such that the compound of formula A x B y X2is overall charge neutral.

[0108] In some embodiments, the silver bismuth sulfide mineral type material comprises a compound of formula ABX2, 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 in the divalent state, which is unstable and readily oxidized. Thus, the silver bismuth sulfide mineral type material of formula ABX2does not contain a divalent cation, such as divalent tin, and is therefore less susceptible to oxidation and has good stability in oxidizing environments.

[0109] In some embodiments, the silver bismuth sulfide mineral type material comprises a compound of formula A x B y X’ z X” 2-z , X comprises a divalent anion X’ and a divalent anion X”, and z is 0-2.

[0110] In some embodiments, the silver bismuth sulfide mineral type material comprises a compound of formula ABX’ z X” 2-z , the first cation A is a monovalent cation, the second cation B is a trivalent cation, X comprises a divalent anion X’ and a divalent anion X”, and z is 0-2.

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

[0112] (1) the divalent anion X’ and the divalent anion X” are different elements;

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

[0114] (3) X" is selected from one or more of O 2- , Se 2- , and Te 2- .

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

[0116] In some embodiments, the first light absorbing layer includes one or more of a perovskite material, a silver bismuth sulfide mineral type material, a crystalline silicon material, copper indium gallium selenide, cadmium telluride, copper zinc tin sulfide, and gallium arsenide; optionally, the first light absorbing layer includes a perovskite material.

[0117] In some embodiments, the perovskite material includes one or more of a compound of the formula A'B'Y3and a compound of the formula A'2CDY6;

[0118] 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;

[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 embodiments, one or more of the following characteristics are satisfied:

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

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

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

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

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

[0126] In some embodiments, one or more of the following features are satisfied:

[0127] (1) The monovalent metal cation in A' comprises one or more of Li + , Na + , K + , Rb + , and Cs + ; the monovalent organic cation comprises one or more of an organic amine ion, a formamidinium ion, and an imidazolium-type ion;

[0128] (2) The divalent metal cation in B' comprises one or more of the divalent cations of Pb, Sn, Zn, Ti, Ni, Fe, Co, Cu, Ga, Ge, Be, Mg, Ca, Sr, Ba, In, Mn, Cr, Mo, and Eu;

[0129] (3) The monovalent metal cation in C comprises one or more of Cs + , Ag + , K + , and Rb + ;

[0130] (4) The trivalent metal cation in D comprises one or more of Bi 3+ , Ni 3+ , Fe 3+ , Sb 3+ , In 3+ , and Cu 3+ ;

[0131] (5) Y comprises one or more of a halide ion and a pseudohalide ion; optionally, Y comprises one or more of F - , Cl - , Br - , I - , CN - , CH3COO - , SCN - , BF4 - , SeCN - , PF6 - .

[0132] In a second aspect, the present application provides a photovoltaic module comprising the laminated solar cell according to the first aspect of the present application.

[0133] In a third aspect, the present application provides a photovoltaic system comprising one or more of the laminated solar cell according to the first aspect of the present application and the photovoltaic module according to the second aspect of the present application.

[0134] In a fourth aspect, the present application provides a power consumption device comprising one or more of the laminated solar cell provided in the first aspect and the photovoltaic module provided in the second aspect.

[0135] In a fifth aspect, the present application provides a power generation device comprising one or more of the laminated solar cell provided in the first aspect and the photovoltaic module provided in the second aspect.

[0136] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF DRAWINGS

[0137] To better describe and illustrate the embodiments or examples provided by the present application, reference can 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 the disclosed application, the presently described embodiments or examples, and any one of the best modes of these applications presently understood. Moreover, in all the drawings, the same reference numbers are used to represent the same components. In the drawings:

[0138] FIG. 1 is a schematic diagram of a solar cell according to an embodiment of the present application.

[0139] FIG. 2 is a schematic diagram of a solar cell according to another embodiment of the present application.

[0140] FIG. 3 is a schematic diagram of a solar cell according to another embodiment of the present application.

[0141] FIG. 4 is a schematic diagram of a solar cell according to another embodiment of the present application.

[0142] FIG. 5 is a schematic diagram of a solar cell according to another embodiment of the present application.

[0143] FIG. 6 is a schematic diagram of a solar cell according to another embodiment of the present application.

[0144] FIG. 7 is a schematic diagram of a cross-section of a first cell unit of a solar cell according to an embodiment of the present application.

[0145] FIG. 8 is a schematic diagram of a power consumption device using the solar cell according to an embodiment of the present application as a power source.

[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 device. DETAILED DESCRIPTION

[0149] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present 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 can understand that the order of writing each step in the method of each embodiment or example does not mean 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. If not specifically stated, all steps of the present application can be performed in sequence or randomly, preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method also comprises step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0155] In the present application, A (such as B) means that B is one non-limiting example of A, and it can be understood that A is not limited to B.

[0156] In the present application, "optionally", "optional" and "optional" mean that it can or can not be present, that is, it means to select any one from the two parallel schemes of "have" or "have". If there are multiple "options" in a technical solution, if there is no special statement and no contradictory relationship or mutual restriction, each "option" is independent.

[0157] Compared with single-junction solar cells, the stacked solar cell can absorb different wavelengths of sunlight because it includes a plurality of different band gap semiconductor materials arranged in layers, so it can more effectively utilize sunlight and has higher conversion efficiency.

[0158] Generally, the stacked solar cell includes a wide-bandgap light-absorbing layer and a narrow-bandgap light-absorbing layer arranged in layers. Taking the direction of incident light from the wide-bandgap light-absorbing layer to the narrow-bandgap light-absorbing layer as an example, the wide-bandgap light-absorbing layer absorbs high-energy photons because the wide-bandgap requires high-energy photons to be excited, and the energy required to move from the valence band to the conduction band is higher, such as ultraviolet light and other shorter-wavelength light. Then the remaining light enters the narrow-bandgap light-absorbing layer and is absorbed by the narrow-bandgap light-absorbing layer, which only needs low-energy photons to be excited, such as infrared light and other longer-wavelength light. In addition, because the diffusion depth of long-wavelength light is deeper, the narrow-bandgap light-absorbing layer is generally arranged in the lower layer. In this way, the battery converts light energy into electrical energy based on the photovoltaic effect.

[0159] The commonly used narrow-bandgap light-absorbing layer includes a crystalline silicon light-absorbing layer or a tin-containing perovskite material. For the tin-containing perovskite material, divalent tin is easily oxidized to tetravalent tin, and is sensitive to water oxygen, which leads to decomposition due to thermal instability, light influence, and chemical instability, and thus the tin-containing perovskite material has poor stability as a narrow-bandgap tandem cell, which further affects the photoelectric conversion efficiency of the tandem cell. For example, the crystal structure of the tin-containing perovskite material is easily changed, leading to decomposition, which destroys the structural integrity of the tin-containing perovskite material and leads to reduced stability.

[0160] An embodiment of the present application provides a tandem solar cell, comprising:

[0161] a first cell unit comprising a first light-absorbing layer;

[0162] a second cell unit comprising a second light-absorbing layer, the second light-absorbing layer comprising a silver bismuth sulfide mineral type material; and

[0163] a connecting layer arranged between the first cell unit and the second cell unit and connecting the first cell unit and the second cell unit.

[0164] The bandgap of the first light-absorbing layer is greater than the bandgap of the second light-absorbing layer.

[0165] The silver bismuth sulfide mineral type material is a kind of semiconductor material, which has light absorption and a high light absorption coefficient, can be used as a photosensitive material to absorb light energy, and has good thermal stability and can be used as a light-absorbing layer of a narrow-bandgap cell to replace the narrow-bandgap light-absorbing layer with poor stability in a tandem solar cell. Thus, the tandem solar cell containing the silver bismuth sulfide mineral type material as a narrow-bandgap cell, the first cell unit being a wide-bandgap cell unit and the second cell unit being a narrow-bandgap cell unit, can absorb a wider spectrum range, effectively utilize solar energy, and has higher stability, and thus the tandem solar cell has good device stability and provides good photoelectric conversion efficiency during long-term operation.

[0166] Further, 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] The traditional stacked solar cell usually uses a tin-containing perovskite material as a narrow-bandgap light-absorbing layer. Since the narrow-bandgap perovskite material generally contains tin, on the one hand, the valence of tin is divalent, and divalent tin ions are unstable and are easily oxidized; on the other hand, the narrow-bandgap perovskite material also contains lead, and the mismatched crystallization rate of tin and lead leads to instability of the structure of the narrow-bandgap perovskite material. The silver bismuth sulfide mineral type material is used as the light-absorbing material of the narrow-bandgap cell, which can avoid the problems of easy oxidation of divalent tin ions and mismatched crystallization rate of tin and lead.

[0168] The term "layer" as used in this application refers to any substantially layer-like structure. A layer can have a thickness that varies over the extent of the layer. Typically, a layer has a thickness that 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 by conventional methods in the art. For example, a Zygo NewView 9000 model white light interferometer can be used for the measurement.

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

[0170] The hexagonal system has one 6-fold symmetry axis or 6-fold inversion axis, which is the vertical crystallographic axis C-axis of the crystal. The other three horizontal crystallographic axes are positive end-to-end at an angle of 120 degrees. Among the axis angles a, b and g, a = b = 90°, g = 120°; among the axis lengths a, b and c, a = b ≠ c.

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

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

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

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

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

[0176] Further, the divalent inorganic anion includes one or more of an oxygen family element, specifically O 2- , S 2- , Se 2- , and Te 2- ; optionally including S 2- .

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

[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 plurality of monovalent, divalent, and trivalent.

[0179] Further, the metal cation includes one or more of 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+ . Optionally, the metal cation includes one or more of Li + , a sodium ion (Na + ), a potassium ion (K + ), a rubidium ion (Rb + ), a cesium ion (Cs + ), a silver ion (Ag + ). More optionally, the metal cation includes a silver ion (Ag + ).

[0180] Further, the organic cation can include one or more of an organic amine ion, a formamidinium ion (HC(NH2)2 + , FA + ), and an imidazolium ion; further, the organic amine ion includes a methylamine ion (CH3NH3 + , MA + ), a dimethylammonium ion (MDA 2+ ), a phenethylammonium ion (PEA + ), and an oleyl ammonium ion (OA +one or more of an ethylammonium ion, a propylammonium ion, a butylammonium ion, a pentylammonium ion, and a hexylammonium ion.

[0181] wherein the imidazolium ion refers to an ion containing an imidazole group and the imidazole group carries a charge; as an example, it includes one or more of an imidazolium ion and a derivative ion of imidazole.

[0182] Further, M includes at least two cations, which are a first cation A and a second cation B, respectively. The first cation A and the second cation B are different in element species.

[0183] Further, the first cation A and the second cation B each independently include one or more of a metal cation and an organic cation, wherein the valence of the metal cation and the organic cation can be any one or any multiple of monovalence to trivalence.

[0184] Further, the first cation A and the second cation B each independently include a metal cation, and the two are different in element species.

[0185] Further, the first cation A and the second cation B each independently include one or more of 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+ , and the two are different in element species.

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

[0187] In some embodiments, the silver bismuth sulfide type material includes a compound of the formula A x B y X2. Wherein x and y are values such that the compound of A x B y X2is overall charge neutral. In other words, x and y are values such that the compound of A x B yThe algebraic sum of the valencies of all atoms in the compound of X2 is equal to zero.

[0188] Further, x and y can be any number from 0 to 4, as examples, 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 a range between any two of the above values.

[0189] Further, X is a divalent anion, and x and y can be values such that A x B y The compound of X2 as a whole can be electrically neutral.

[0190] Further, the divalent anion includes one or more of O 2- , S 2- , Se 2- , and Te 2- ; optionally, X includes S 2- .

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

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

[0193] In some embodiments, the silver bismuth sulfide type material includes a compound of the formula ABX2, the first cation A is a monovalent cation, the second cation B is a trivalent cation, and X is a divalent anion. The perovskite material generally contains tin elements, and the valence of the tin element is divalent. The divalent tin ion is unstable and is easily oxidized. Thus, the silver bismuth sulfide type material of the formula ABX2 does not contain divalent tin ions, and thus is not easily oxidized and has good stability in an oxidizing environment.

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

[0195] Further, X comprises a divalent anion X' and a divalent anion X", then the chemical formula is A x B y X2, the chemical formula is A x B y X' z X" 2-z , wherein z is 0-2. The value of z can be any number in the range of 0 to 2, as an 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 a range consisting of any two of the above values as end values.

[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 a value in the range of 0-2 that is not an end value, and the divalent anion X' and the divalent anion X" are different in element, it means that two different divalent anions X' and X" exist at the same time. Further, X' is S 2- , and z is not 0. Further, X" is selected from one or more of O 2- , Se 2- , and Te 2- . Further, the chemical formula is A x B y X2, the chemical formula is A x B y S z X" 2-z .

[0197] As an example, the chemical formula is A x B y X2, the chemical formula is 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 .

[0198] Further, the first cation A is a monovalent cation, the second cation B is a trivalent cation, and X comprises a divalent anion X' and a divalent anion X", then the chemical formula is ABX2, the chemical formula is ABX' z X" 2-zwherein z is 0-2. The value of z can be any number in the range of 0 to 2, and as examples 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 a range defined by any two of the above values as endpoints.

[0199] When z is 0, the divalent anion X' is absent, and when z is 2, the divalent anion X" is absent. When z is a value in the range of 0-2 that is not an endpoint, then both divalent anions X' and X" are present. Further, X' is S 2- and z is not 0. Further, X" is selected from one or more of O 2- , Se 2- , and Te 2- . Further, the compound of formula ABX2is of formula ABS z X" 2-z .

[0200] As examples, the compound of formula ABX2includes, but is not limited to, one or more of AgBiS2, AgBiS z O 2-z , AgBiS z Se 2-z , AgBiS z Te 2-z .

[0201] Further, as an example, AgBiS2includes one or more of a cubic rock salt phase and a hexagonal phase. Optionally, the above-mentioned tandem solar cell includes AgBiS2in a cubic rock salt phase, which has the advantages of high absorption coefficient, suitable band gap, good charge transport performance, and good material stability.

[0202] Silver bismuth sulfide type materials can be formed using hydrothermal method, solvothermal method, chemical vapor deposition (CVD), precursor pyrolysis method, sol-gel method, etc.

[0203] In some embodiments, the silver bismuth sulfide type material is a nanocrystal, such as a quantum dot, with a particle size of 2-10 nm. However, the synthesis of nanocrystals is complex, and there are a large number of surface traps on the surface of the nanocrystals, which results in low carrier transport rate and serious recombination, thereby restricting the charge extraction efficiency.

[0204] In some embodiments, the silver bismuth sulfide mineral type material has a grain size of 10 nm or more, and optionally in the range of 10 nm to 10 μιη, and by way of example, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μιη, 2 μιη, 3 μιη, 4 μιη, 5 μιη, 6 μιη, 7 μιη, 8 μιη, 9 μιη, 10 μιη, or a range defined by any two of the aforementioned values as endpoints.

[0205] In some embodiments, the silver bismuth sulfide mineral type material has a grain size in the range of 10 nm to 5 μιη or 500 nm to 5 μιη. Optionally, the silver bismuth sulfide mineral type material has a grain size in the range of 10 nm to 1 μιη or 500 nm to 1 μιη. A large grain size of the silver bismuth sulfide mineral type material reduces the grain boundaries, and reduces non-radiative recombination of electrons and holes at the grain boundaries.

[0206] In some embodiments, the silver bismuth sulfide mineral type material has a grain size in the range of 1 μιη to 10 μιη. Optionally, the silver bismuth sulfide mineral type material has a grain size in the range of 5 μιη to 10 μιη, or 1 μιη to 5 μιη, or 4 μιη to 6 μιη.

[0207] In some embodiments, the silver bismuth sulfide mineral type material has a grain size in the range of 10 nm to 500 nm, or 50 nm to 500 nm. Optionally, the silver bismuth sulfide mineral type material has a grain size in the range of 10 nm to 400 nm, or 50 nm to 400 nm. Optionally, the silver bismuth sulfide mineral type material has a grain size in the range of 10 nm to 200 nm, or 50 nm to 200 nm. Optionally, the silver bismuth sulfide mineral type material has a grain size in the range of 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 agray bismuth sulfide mineral type material includes one or both of polycrystalline and single crystal. Polycrystalline refers to a crystalline particle with grain boundaries, which are the interface regions between different grains in a polycrystalline material. Single crystal refers to a crystal formed by long-range ordered arrangement of structural units in three-dimensional space. Polycrystalline refers to a material composed of multiple grains, which are crystalline bodies formed by ordered arrangement of atoms or molecules. The lattice of each grain is periodically arranged, but the orientation of these grains is random. Because the orientations of the grains are different, there are grain boundaries between the crystalline particles. Single crystal has ordered and regular structure due to the internal atomic arrangement, and the atomic arrangement in each direction is consistent, so there is no grain boundary. In other words, the agray bismuth sulfide mineral type material includes one or both of polycrystalline agray bismuth sulfide mineral type material and single crystal agray bismuth sulfide mineral type material.

[0209] In some embodiments, the band gap of the agray bismuth sulfide mineral type material is 0.8 eV to 1.4 eV, optionally 0.8 eV to 1.2 eV, and more optionally 0.9 eV to 1.1 eV. As an example, the band gap of the agray bismuth sulfide mineral type 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 a range formed by any two of the above values as end values. The band gap of the agray bismuth sulfide mineral type material in the above range can be a good narrow-band-gap light-absorbing material, which has the advantages of high absorption coefficient, suitable band gap, good charge transport performance, and good material stability. The thin film thereof can achieve high current density in a 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. The chemical formula is A x B y X2. Thus, the agray bismuth sulfide mineral type material with the chemical formula ABX2 does not contain divalent cations, such as divalent tin ions, and is not easily oxidized, so it has good stability in an oxidizing environment and does not have the problem of mismatched crystallization rate of tin and lead.

[0211] In some embodiments, the second light absorbing layer has a thickness of 10 nm to 20 μm, for example, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, or a range between any two of the aforementioned values.

[0212] Further, the second light absorbing layer has a thickness of 10 nm to 10 μm, or 500 nm to 10 μm. Alternatively, the second light absorbing layer has a thickness of 10 nm to 5 μm, or 500 nm to 5 μm.

[0213] Further, the second light absorbing layer has a thickness of 1 μm to 20 μm. Alternatively, the second light absorbing layer has a thickness of 5 μm to 20 μm.

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

[0215] The silver bismuth sulfide type material has a high light absorption coefficient, and a thin film thereof can achieve a high current density in a small thickness range.

[0216] In some embodiments, the first light absorbing layer has a band gap of 1.5 eV to 1.9 eV, optionally 1.53 eV to 1.65 eV. For example, the first light absorbing layer can have a band gap of 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 a range defined by any two of the above values as endpoints.

[0217] Further, the second light absorbing layer has a band gap of 0.8 eV to 1.2 eV, optionally 0.9 eV to 1.1 eV. For example, the silver bismuth sulfide type material can have a band gap of 0.8 eV, 0.85 eV, 0.9 eV, 0.95 eV, 1 eV, 1.1 eV, 1.2 eV, or a range defined by any two of the above values as endpoints. The silver bismuth sulfide type material has a band gap in the above range, which is a good narrow-band gap light absorbing material, having high absorption coefficient, suitable band gap, good charge transport performance, good material stability, etc., and its thin film can achieve high current density in a small thickness range.

[0218] Further, the first light absorbing layer has a band gap of 1.5 eV to 1.9 eV, and the second light absorbing layer has a band gap of 0.9 eV to 1.1 eV; this can effectively absorb light of long and short wavelengths, thereby improving the photoelectric conversion efficiency.

[0219] In some embodiments, the first light absorbing layer includes one or more semiconductor materials selected from the group consisting of perovskite material, silver bismuth sulfide type material, crystalline silicon material, copper indium gallium selenium, cadmium telluride, copper zinc tin sulfide, and gallium arsenide. In this application, the first light absorbing layer can be matched with the second light absorbing layer of the silver bismuth sulfide type material, so that the obtained stacked solar cell can absorb a wider spectrum range and improve the efficient use of solar energy.

[0220] In some embodiments, the first light absorbing layer includes one or more semiconductor materials selected from the group consisting of perovskite material, copper indium gallium selenium, cadmium telluride, copper zinc tin sulfide, and gallium arsenide.

[0221] Further, the first light absorbing layer includes 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 of the formula A’B’Y3 and a compound of the formula A’2CDY6.

[0223] wherein A' comprises a monovalent cation, B' comprises a divalent cation, C comprises a monovalent cation, D comprises a trivalent cation, and Y comprises 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' comprises one or more of Li + , Na + , K + , Rb + , and Cs + . The monovalent organic cation comprises one or more of an organic amine ion, a formamidinium ion, and an imidazolium-type ion. Further, the organic amine ion comprises one or more of a methylamine ion (CH3NH3 + , MA + ), a dimethylammonium ion (MDA 2+ ), a phenethylammonium ion (PEA + ), an oleyl ammonium ion (OA + ), an ethylamine ion, a propylamine ion, a butylamine ion, a pentylamine ion, and a hexylamine ion.

[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 one or more of Cs + , Ag + , K + , and Rb + .

[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 comprises one or more of Bi 3+ , Ni 3+ , Fe 3+ , Sb 3+ , In 3+ , and Cu 3+ .

[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 one or more of F - , Cl - , Br - , I - , CN - , CH3COO - , SCN - , BF4 - , SeCN - , PF6 - .

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

[0230] The perovskite material layer can be prepared by methods commonly used in the art, including but not limited to sol-gel method, coating, multi-source co-evaporation, etc. It can be understood that the coating can be implemented by, but not limited to, spin coating, slot coating, brush coating, wiping coating, blade coating, screen printing and spraying, etc. Further, the perovskite material layer is a three-dimensional perovskite film.

[0231] As an example, the perovskite material in the perovskite material layer can comprise 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 perovskite light absorbing layer can be selected from one or more of CsFAPbI3, CsPbI3, FAPbI3.

[0232] As an example, the perovskite material has a general formula as follows: Cs a FA b MA c Pb d Sn e I f Br g , wherein 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 stacked solar cell comprises: a first electrode and a second electrode; the first cell unit comprises the first electrode, which is disposed on a side of the first light-absorbing layer away from the connecting layer; and the second cell unit comprises the second electrode, which is disposed on a side of the second light-absorbing layer away from the connecting layer.

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

[0235] In some embodiments, the light-transmitting electrode refers to an electrode having light-transmitting property for visible light. Further, the light-transmitting electrode has a light transmittance for visible light ≥ 50%, optionally ≥ 60%, or ≥ 70%, or ≥ 80%, or ≥ 85%, or ≥ 90%. As an example, the light transmittance of the light-transmitting electrode for visible light can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or a range formed by any two of the above values as end values. Further, the light transmittance of the light-transmitting electrode for visible light can be 50% to 100%, optionally 60% to 80% or 80% to 100% or 80% to 95%.

[0236] In some embodiments, the first cell unit further comprises 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-absorbing layer;

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

[0239] In some embodiments, 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.

[0240] In some embodiments, the second cell unit further comprises 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-absorbing layer;

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

[0243] In some embodiments, 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.

[0244] Thus, by setting the charge transport layer, the efficiency of the battery cell charge transport and extraction can be improved.

[0245] In some embodiments, the connecting layer includes a recombination layer, holes from the first battery cell and electrons from the second battery cell, or electrons from the first battery cell and holes from the second battery cell recombine and annihilate in the recombination layer, thereby achieving circuit connection of the two battery cells. The connecting layer includes a recombination layer, and the preparation of the stacked solar cell is simple, the top cell can be directly deposited on the bottom cell to form a single complete cell with a total of two electrodes, forming a two-terminal stacked solar cell.

[0246] The working principle of the stacked solar cell with a connecting layer including a recombination layer: two battery cells with different bandgaps are connected in series through the recombination layer, so that they can absorb sunlight in different wavelength ranges, thereby improving the photoelectric conversion efficiency of the entire cell. Sunlight is incident from the bottom cell, the bottom cell 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, the top cell absorbs this portion of the sunlight and generates additional voltage and current, the voltages of the two are added, and the currents are matched (take the lower value) to output. The structure design is relatively simple, reducing the number of electrodes and connecting layers, reducing the complexity and cost of the cell; by selecting appropriate battery cell combinations and optimizing the stacked structure, a higher photoelectric conversion efficiency can be achieved; due to the relatively simple structure, better stability, reducing the links that may fail or performance decline.

[0247] In some embodiments, the stacked solar cell includes a first electrode, a first charge transport layer, a first light absorbing layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorbing layer, a fourth charge transport layer, and a second electrode arranged in layers. Further, the charge transport layers on both sides of the recombination layer cannot be electron transport layers at the same time, nor can they be hole transport layers at the same time. In other words, 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. Alternatively, 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.

[0248] In some embodiments, the components of the recombination layer include one or more of metal materials, transparent conductive oxides, and carbon materials.

[0249] Further, the transparent conductive oxide layer includes, but is 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). Further, the metallic material includes, but is not limited to, one or more of gold, copper, silver, platinum, aluminum, and iron. Further, the carbon material includes one or more of graphite, graphene, and carbon nanotube.

[0250] Further, the composite layer can be a stack of one or more of a metallic 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] Further, the metallic layer includes, but is not limited to, a gold layer.

[0252] In some embodiments, the composite layer has a thickness of 0.1 nm to 200 nm, such as 0.1 nm, 0.5 nm, 0.8 nm, 1 nm, 1.2 nm, 1.5 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 90 nm, 100 nm, 130 nm, 150 nm, 160 nm, 180 nm, 190 nm, 200 nm, or a range defined by any two of the above values as endpoints, such as 0.5 nm to 10 nm, 0.5 nm to 3 nm, further such as 0.8 nm to 1.2 nm.

[0253] In other embodiments, the connecting layer includes an insulating layer. The stacked solar cell further includes a third electrode and a fourth electrode, 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. The connecting layer with the insulating layer thus electrically isolates the first cell unit and the second cell unit, each of the two cell units has two electrodes, a total of four electrodes, and the circuit of the two cell units is independent of each other, forming a four-terminal stacked solar cell.

[0254] In some embodiments, the first cell unit includes a first electrode, a first light absorbing layer, and a third electrode, which are sequentially stacked. The second cell unit includes a fourth electrode, a second light absorbing layer, and a second electrode, which are sequentially stacked.

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

[0256] The four-terminal tandem solar cell has lower requirements for the current and voltage matching of the cell units, because each cell unit works independently and does not need to be accurately matched in current and voltage, unlike the two-terminal tandem solar cell; the four-terminal tandem solar cell can more flexibly select different types and performance of cell units for combination to adapt to different application scenarios and requirements; and the performance loss caused by the mutual influence between the cell units is reduced to a certain extent.

[0257] Further, the third electrode and the fourth electrode are located at the middle position 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 being absorbed by the previous cell unit to enter the next cell unit, the third electrode and the fourth electrode can also be set as light-transmitting electrodes.

[0258] Further, at least one of the first electrode and the second electrode is a light-transmitting electrode. Further, only one of the first electrode and the second electrode is a light-transmitting electrode, and the light-transmitting electrode serves as the incident side of the sunlight. Further, both the first electrode and the second electrode are light-transmitting electrodes, and both electrodes can serve as the incident side of the sunlight. For example, the solar light can be incident from both sides, which is conducive to improving the sunlight intensity received by the tandem solar cell.

[0259] In some embodiments, as an example of the 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 which are arranged in layers.

[0260] Since the circuits of the cell units in the four-terminal tandem solar cell are independent, the types of the charge transport layers located on both sides of the connecting layer or the insulating layer are not limited and can be arbitrarily combined. In other words, the materials of the second charge transport layer and the third charge transport layer can be the same or different, and each can independently be an electron transport layer or a hole transport layer. Further, 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.

[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 derivatives, dopants, and passivated versions of the resulting materials: [6,6]-phenyl C61 butyric acid methyl ester (PC61BM), [6,6]-phenyl C71 butyric acid methyl ester (PC71BM), fullerene C60 (C60), fullerene C61, fullerene C70 (C70), tin dioxide (Sn02), zinc oxide (ZnO), perylene imide (PDI)-based materials, naphthalene imide (NDI)-based materials, and the like.

[0263] Further, the electron transport layer has a thickness of 1 nm to 300 nm, which, by way of example, 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 a range defined by any two of the aforementioned values as endpoints. Further, the electron transport layer has a thickness of 1 nm to 100 nm; further, 5 nm to 100 nm; further, 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 derivatives, dopants, and passivated versions of the resulting materials:

[0265] nickel oxide, molybdenum oxide, molybdenum sulfide, cuprous oxide, cuprous iodide, cuprous thiocyanate, 2,2',7,7'-tetrakis(N,N-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-OMeTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, poly-3-hexylthiophene, methoxytriphenylamine-fluoroformamid, triptycene-core triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-4-anilino carbazole-spirobifluorene, polythiophene, and self-assembled monomolecular materials.

[0266] In some embodiments, the self-assembled monomolecular material satisfies the structure shown in the following general formula: Q-L-A, wherein Q is selected from substituted or unsubstituted carbazolyl or triphenylamino, L is selected from substituted or unsubstituted alkylene chain, and A is selected from oxygen-containing acid group.

[0267] In some embodiments, the substituent of the substituted or unsubstituted carbazolyl or triphenylaminyl in the self-assembled monomolecular material includes any one of a halogen group, an alkoxy group, an oxygen-containing acid group, a substituted or unsubstituted aromatic group having 6 to 15 ring-forming atoms, a substituted or unsubstituted heteroaromatic group having 5 to 15 ring-forming atoms, and a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms. In the present application, the structure of the substituent of the substituted or unsubstituted carbazolyl or triphenylaminyl is such that the organic compound has an energy level more suitable for a perovskite material, and when applied to the preparation of a hole transport layer of a solar cell, the performance of the solar cell is further improved.

[0268] In some embodiments, the substituted or unsubstituted alkylene chain in the self-assembled monomolecular material includes any one of a substituted or unsubstituted alkylene chain having 2 to 11 carbon atoms substituted with a halogen group, an alkoxy group, an oxygen-containing acid group, an aromatic group having 6 to 15 ring-forming atoms, or a heteroaromatic group having 5 to 15 ring-forming atoms. By adjusting the number of carbon atoms in L and its substituents, the hydrophobicity of the organic compound is improved while reducing the steric hindrance of the organic compound, and the photoelectric conversion efficiency and stability of the solar cell are further improved.

[0269] In some embodiments, the oxygen-containing acid group in the self-assembled monomolecular material is selected from any one of a phosphonic acid group, a hypophosphorous acid group, a sulfonic acid group, a carboxylic acid group, a sulfinic acid group, a boric acid group, or a silicic acid group.

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

[0271] In some embodiments, the heteroatom in the heteroaromatic group is selected from at least one of N, O, and S, so that the organic compound has an energy level more suitable for commonly used metal oxide hole transport materials and perovskite materials, and when applied to the preparation of a passivation film of a solar cell, the performance of the solar cell is further improved.

[0272] In some embodiments, the alkoxy group is generally represented by RO-, and examples include methoxy CH3O-, ethoxy C2H5O-, propoxy C3H7O-, and the like.

[0273] In some embodiments, the self-assembled monomolecular material comprises at least one of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz), [4-(9H-carbazol-9-yl)butyl]phosphonic acid (4PACz), [4-(3,6-dibromo-9H-carbazol-9-yl)butyl]phosphonic acid (Br-4PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), [2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl]phosphonic acid (Me-2PACz), [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dibromo-9H-carbazol-9-yl)ethyl]phosphonic acid (Br-2PACz). The self-assembled monomolecular material is selected from the above-mentioned materials, has good hole transport efficiency, and has good energy level matching with the perovskite layer, which is conducive to improving the photoelectric conversion efficiency of the perovskite solar cell.

[0274] Further, the thickness of the hole transport layer is 1 nm to 500 nm, which 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, 320 nm, 350 nm, 360 nm, 380 nm, 400 nm, 440 nm, 480 nm, 500 nm, or a range formed by any two of the above-mentioned values as end values. Further, the thickness of the hole transport layer is 1 nm to 300 nm, which can be 1 nm to 100 nm, 5 nm to 100 nm, or 1 nm to 50 nm.

[0275] Understandably, in the stacked solar cell, one or more of the first charge transport layer, the second charge transport layer, the third charge transport layer, and the fourth charge transport layer can be included.

[0276] Referring to FIG. 1, as an example, the stacked solar cell 10 includes a first electrode 210, a first charge transport layer 310, a first light absorbing layer 110, a second charge transport layer 320, a connecting layer 900, a third charge transport layer 330, a second light absorbing layer 120, a fourth charge transport layer 340, and a second electrode 220 which are stacked.

[0277] Further, the solar cell further comprises a substrate, and the first electrode is disposed on the substrate. The substrate can be glass, so that the substrate and the first electrode material form transparent conductive glass. The transparent conductive glass can be, for example, FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), and the like.

[0278] It can be understood that the solar cell includes a formal structure and an inverse structure in terms of structure. The first electrode is a light-transmitting electrode, and the first electrode is disposed on the substrate. The formal structure of the stacked solar cell is determined according to the formal or inverse of the first cell unit. If the first cell unit comprises a first electrode, an electron transport layer, a first light-absorbing layer, and a hole transport layer disposed in sequence, the stacked solar cell is a formal structure. If the first cell unit comprises a first electrode, a hole transport layer, a first light-absorbing layer, and an electron transport layer disposed in sequence, the stacked solar cell is an inverse structure.

[0279] Since the first electrode is a light-transmitting electrode, it serves as the solar light incident side. In the inverse structure, the film layer located near the solar light incident side of the light-absorbing layer is the hole transport layer. Therefore, the side of the light-absorbing layer near the hole transport layer generates more holes due to the photovoltaic effect, which can make the hole concentration in the hole transport layer higher. Since the hole transport rate is slower than the electron transport rate, the hole transport layer is disposed near the solar light incident side. The holes generated on the side of the light-absorbing layer near the hole transport layer do not need to cross the entire light-absorbing layer, thus shortening the transport path, which is beneficial to improving the hole collection rate. In addition, through the inverse structure, it is beneficial to improve the rate matching of the hole transport rate and the electron transport rate.

[0280] Please continue to refer to FIG. 1. As an example, the stacked solar cell 10 comprises a substrate 800, a first electrode 210, a first charge transport layer 310, a first light-absorbing layer 110, a second charge transport layer 320, a connecting layer 900, a third charge transport layer 330, a second light-absorbing layer 120, a fourth charge transport layer 340, and a second electrode 220 disposed in sequence.

[0281] As an example of the formal structure of the solar cell, please refer to FIG. 1. The stacked solar cell 10 comprises a substrate 800, a first electrode 210, a first charge transport layer 310, a first light-absorbing layer 110, a second charge transport layer 320, a connecting layer 900, a third charge transport layer 330, a second light-absorbing layer 120, a fourth charge transport layer 340, and a second electrode 220 disposed in sequence. At this time, 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] Further, in the case where the connecting layer 900 comprises a composite layer, the stacked solar cell 10 is a two-terminal stacked solar cell, and the third charge transport layer 330 is an electron transport layer, and the fourth charge transport layer 340 is a hole transport layer.

[0283] Please refer to FIG. 2, further, in the case where the connecting layer 900 comprises an insulating layer, the stacked solar cell 10 is a four-terminal stacked solar cell, and either of the third charge transport layer 330 and the fourth charge transport layer 340 is an electron transport layer, and the other is a hole transport layer. The stacked solar cell 10 further comprises a third electrode 230 and a fourth electrode 240, the third electrode 230 is disposed between the first light absorbing 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 absorbing 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 the reverse structure of the solar cell, please refer to FIG. 1, the solar cell 10 comprises a substrate 800, a first electrode 210, a first charge transport layer 310, a first light absorbing layer 110, a second charge transport layer 320, a connecting layer, a third charge transport layer 330, a second light absorbing layer 120, a fourth charge transport layer 340 and a second electrode 220 which are stacked; at this time, 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 at this time, 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 at this time, the third charge transport layer 330 and the fourth charge transport layer 340 can be the same or different, and each is independently an electron transport layer or a hole transport layer.

[0285] In some embodiments, the first cell and the second cell are connected by a common electrode. For example, a common fifth electrode is used for the connection, and the second electrode in the second cell is disposed opposite to the common fifth electrode. In this way, the stacked solar cell comprises a first electrode, a first light absorbing layer, a common fifth electrode, a second light absorbing layer and a second electrode which are stacked in sequence. The fifth electrode, as a common electrode, can be used as a positive electrode or a negative electrode for output, and the first electrode and the second electrode are electrodes opposite to the common electrode in polarity, thus forming a three-terminal stacked solar cell. The two cells in the three-terminal stacked solar cell are connected in parallel, and there is no problem of current mismatch.

[0286] Further, the common electrode has a large thickness, but is generally smaller than the total thickness of the third electrode and the fourth electrode in the four-terminal stacked solar cell, so that the amount of electrode material can be reduced, and the cost can be reduced to some extent.

[0287] Further, the common electrode comprises a transparent conductive oxide layer, a gate line electrode layer and another transparent conductive oxide layer which are stacked. The transparent conductive oxide layer can play a good light transmission role, and the gate line electrode layer can improve the collection of carriers on the basis of occupying as little light absorption area as possible. Further, the gate line electrode layer comprises a metal gate line.

[0288] In some embodiments, the first cell unit further comprises a first passivation layer arranged on a side of the first light-absorbing layer facing the first electrode, and optionally, the first passivation layer is arranged on at least part 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 part of the surface of the first light-absorbing layer facing the first electrode, and improve the stability and light absorption efficiency of the first light-absorbing layer.

[0289] In this application, "at least part of the surface" can be part or all of the surface, and the like hereinafter.

[0290] In some embodiments, the first cell unit further comprises a second passivation layer arranged on a side of the first light-absorbing layer facing the connecting layer, and optionally, the second passivation layer is arranged on at least part 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 part of the surface of the first light-absorbing layer facing the connecting layer, and improve the stability and light absorption efficiency of the first light-absorbing layer.

[0291] In some embodiments, the second cell unit further comprises a third passivation layer arranged on a side of the second light-absorbing layer facing the connecting layer, and optionally, the third passivation layer is arranged on at least part 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 part of the surface of the second light-absorbing layer facing the connecting layer, and improve the stability and light absorption efficiency of the second light-absorbing layer.

[0292] In some embodiments, the second cell unit further comprises a fourth passivation layer arranged on a side of the second light-absorbing layer facing the second electrode, and optionally, the fourth passivation layer is arranged on at least part 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 part of the surface of the second light-absorbing layer facing the second electrode, and improve the stability and light absorption efficiency of the second light-absorbing layer.

[0293] In some embodiments, the first cell unit comprises a first passivation layer and a first charge transport layer, and the first passivation layer is arranged between the first charge transport layer and the first light-absorbing layer.

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

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

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

[0297] In some embodiments, the material of the first passivation layer and the second passivation layer is a material for passivating the first light absorbing layer, the material of the first passivation layer and / or the second passivation layer is chemically bonded with anions or cations of the material of the first light absorbing layer. The bulk structure of the first light absorbing layer material crystal can generate anion or cation defects, and the material of the first passivation layer and / or the second passivation layer can be chemically bonded with the anions or cations at the defect sites to passivate the defects, reduce non-radiative recombination of carriers, and improve the conversion efficiency of the solar cell.

[0298] For example, the first light absorbing material includes a perovskite material, the perovskite material can generate anion vacancy defects such as iodine vacancy defects, bromine vacancy defects, and / or cation vacancy defects such as A-site cation defects during crystallization. By selecting a material that can be chemically bonded with anions or cations of the perovskite material, the above defects can be passivated, and non-radiative recombination caused by defects can be improved.

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

[0300] In some embodiments, the material of the third passivation layer and / or the fourth passivation layer is chemically bonded with anions or cations of the material of the second light absorbing layer. Further, the material of the third passivation layer and the fourth passivation layer can be used for but not limited to passivating cation sites or anion sites in silver bismuth sulfide type materials, especially divalent anion sites, such as S2- defects of the group-va element sites are passivated.

[0301] In some embodiments, the thickness of the first passivation layer, the second passivation layer, the third passivation layer, and the fourth passivation layer can be the same or different, each independently 1 nm to 20 nm, for example, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 15 nm, 16 nm, 20 nm, or a range formed by any two of the above values as end values.

[0302] Understandably, in the stacked solar cell, one or more of the first passivation layer, the second passivation layer, the third passivation layer, and the fourth passivation layer can be included.

[0303] In some embodiments, the stacked solar cell includes a first electrode, 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 connection 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, and a second electrode.

[0304] Referring to FIG. 3, for example, the stacked solar cell 10 includes a substrate 800, a first electrode 210, a first passivation layer 410, a first light absorbing layer 110, a second passivation layer 420, a connection layer 900, a third passivation layer 430, a second light absorbing layer 120, a fourth passivation layer 440, and a second electrode 220 stacked.

[0305] In some embodiments, the stacked solar cell includes a first electrode, 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 connection 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, and a second electrode.

[0306] Referring to FIG. 4, for 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 absorbing layer 110, a second passivation layer 420, a second charge transport layer 320, a connection layer 900, a third charge transport layer 330, a third passivation layer 430, a second light absorbing layer 120, a fourth passivation layer 440, a fourth charge transport layer 340, and a second electrode 220 stacked.

[0307] In some embodiments, the stacked solar cell includes a first electrode, an optional first charge transport layer, a first light absorbing layer, an optional second charge transport layer, a connection layer, an optional third charge transport layer, a second light absorbing layer, an optional fourth charge transport layer, and a second electrode.

[0308] As an example, the stacked solar cell includes a substrate, a first electrode, a first charge transport layer, a first light absorbing layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorbing layer, a fourth charge transport layer, and a second electrode, which are stacked.

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

[0310] It is appreciated that the barrier layer is used to prevent the reverse transmission of carriers (electrons or holes), so as to avoid the recombination of carriers, thereby improving the open circuit voltage and photoelectric conversion efficiency of the cell. In some embodiments, the stacked solar cell includes the first barrier layer and the first charge transport layer described above. Further, the first barrier layer can be disposed between the first electrode and the first charge transport layer. Further, the first barrier layer can be disposed between the first charge transport layer and the first light absorbing layer. It is appreciated that the first barrier layer can be disposed between the first electrode and the first charge transport layer, between the first charge transport layer and the first light absorbing layer, or both.

[0311] Further, when the first charge transport layer described above is an electron transport layer, the first barrier layer is a hole barrier layer. The function of the hole barrier layer is to transport electrons and block holes, so as to reduce the recombination of electrons and holes, thereby improving the open circuit voltage and photoelectric conversion efficiency of the cell. Further, when the first charge transport layer described above is a hole transport layer, the first barrier layer is an electron barrier layer. The function of the electron barrier layer is to transport holes and block electrons, so as to reduce the recombination of electrons and holes, thereby improving the open circuit voltage and photoelectric conversion efficiency of the cell.

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

[0313] In some embodiments, the stacked solar cell includes the second barrier layer and the second charge transport layer described above. Further, the second barrier layer can be disposed between the second charge transport layer and the connecting layer. Further, the second barrier layer can be disposed between the first light absorbing layer and the second charge transport layer. It is appreciated that the second barrier layer can be disposed between the second charge transport layer and the connecting layer, between the first light absorbing layer and the second charge transport layer, or both.

[0314] Further, the second charge transport layer is an electron transport layer, and the second barrier layer is a hole barrier layer. The function of the hole barrier layer is to transport electrons and block holes, so as to reduce the recombination of electrons and holes, and improve the open circuit voltage and photoelectric conversion efficiency of the cell. Further, the second charge transport layer is a hole transport layer, and the second barrier layer is an electron barrier layer. The function of the electron barrier layer is to transport holes and block electrons, so as to reduce the recombination of electrons and holes, and improve the open circuit voltage and photoelectric conversion efficiency of the cell.

[0315] Further, one of the first barrier layer and the second barrier layer is an electron barrier layer, and the other is a hole barrier layer. In some embodiments, the stacked solar cell further comprises a third barrier layer, which is arranged between the connecting layer and the second light absorbing layer.

[0316] In some embodiments, the stacked solar cell comprises a third barrier layer and the third charge transport layer described above. Further, the third barrier layer is arranged between the connecting layer and the third charge transport layer. Further, the third barrier layer is arranged between the third charge transport layer and the second light absorbing layer. Understandably, the third barrier layer can be arranged between the connecting layer and the third charge transport layer, between the third charge transport layer and the second light absorbing layer, or both.

[0317] Further, the third charge transport layer is an electron transport layer, and the third barrier layer is a hole barrier layer. The function of the hole barrier layer is to transport electrons and block holes, so as to reduce the recombination of electrons and holes, and improve the open circuit voltage and photoelectric conversion efficiency of the cell. Further, the third charge transport layer is a hole transport layer, and the third barrier layer is an electron barrier layer. The function of the electron barrier layer is to transport holes and block electrons, so as to reduce the recombination of electrons and holes, and improve the open circuit voltage and photoelectric conversion efficiency of the cell.

[0318] In some embodiments, the stacked solar cell further comprises a fourth barrier layer, which is arranged between the second light absorbing layer and the second electrode.

[0319] In some embodiments, the stacked solar cell comprises a fourth barrier layer and the fourth charge transport layer described above. Further, the fourth barrier layer is arranged between the fourth charge transport layer and the connecting layer. Further, the fourth barrier layer is arranged between the second light absorbing layer and the fourth charge transport layer. Understandably, the fourth charge transport layer and the connecting layer, the second light absorbing layer and the fourth charge transport layer, or both can be arranged with the fourth barrier layer.

[0320] Further, the fourth charge transport layer is an electron transport layer, and the fourth barrier layer is a hole barrier layer. The function of the hole barrier layer is to transport electrons and block hole transport, so as to reduce the recombination of electrons and holes, and improve the open circuit voltage and photoelectric conversion efficiency of the cell. Further, the fourth charge transport layer is a hole transport layer, and the fourth barrier layer is an electron barrier layer. The function of the electron barrier layer is to transport holes and block electron transport, so as to reduce the recombination of electrons and holes, and improve the open circuit voltage and photoelectric conversion efficiency of the cell.

[0321] Further, one of the third barrier layer and the fourth barrier layer is an electron barrier layer, and the other is a hole barrier layer.

[0322] Further, if the stacked solar cell is a two-terminal stacked solar cell, one of the second barrier layer and the third barrier layer is an electron barrier layer, and the other is a hole barrier layer.

[0323] Further, the LUMO (lowest unoccupied molecular orbital) energy level of the material of the hole barrier layer is lower than the conduction band bottom CBM of the material of the light absorbing layer of the corresponding cell unit, and the HOMO (highest occupied molecular orbital) energy level of the material of the hole barrier layer is lower than the valence band top VBM of the material of the light absorbing layer of the corresponding cell unit, so that the function of transporting electrons and blocking holes can be achieved.

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

[0325] Further, the material of the hole barrier layer includes but is not limited to one or more of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP), SnO2, ZnO, and cerium oxide (CeOx), x is any value within 0-2.

[0326] Further, the thickness of the hole barrier layer is 0.5 nm-50 nm, further 1 nm-50 nm, 0.5 nm-20 nm, or 1 nm-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 a range formed by any two of the above as end values.

[0327] Further, the LUMO energy level of the material of the electron barrier layer is higher than the conduction band bottom CBM of the material of the light absorbing layer of the corresponding cell unit, and the HOMO energy level of the material of the electron barrier layer is higher than the valence band top VBM of the material of the light absorbing layer of the corresponding cell unit, so that the function of transporting holes and blocking electrons can be achieved.

[0328] Further, the electron blocking layer includes, but is not limited to, one or more of molybdenum oxide, vanadium oxide, LiF, and AI2O3. Optionally, the electron blocking layer includes AI2O3. Further, the electron blocking layer has a thickness of 0.5 nm to 50 nm, further 1 nm to 50 nm, 0.5 nm to 20 nm, or 1 nm to 20 nm, as an example, 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 a range defined by any two of the above values as end values.

[0329] Further, the first and second blocking layers can have the same or different thicknesses, each independently of the other, of 0.5 nm to 50 nm, as an example, 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 a range defined by any two of the above values as end values.

[0330] In some embodiments, the tandem solar cell includes a first electrode, an optional first blocking layer, an optional first charge transport layer, a first light absorbing layer, an optional second charge transport layer, a connecting layer, an optional third charge transport layer, a second light absorbing layer, an optional fourth charge transport layer, an optional fourth blocking layer, and a second electrode, stacked in that order.

[0331] As an example, the tandem solar cell includes a substrate, a first electrode, a first blocking layer, a first charge transport layer, a first light absorbing layer, a second charge transport layer, a connecting layer, a third charge transport layer, a second light absorbing layer, a fourth charge transport layer, a fourth blocking layer, and a second electrode, stacked in that order.

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

[0333] As an example, the tandem solar cell includes a substrate, a first electrode, a first charge transport layer, a first light absorbing layer, a second charge transport layer, a second blocking layer, a connecting layer, a third blocking layer, a third charge transport layer, a second light absorbing layer, a fourth charge transport layer, and a second electrode, stacked in that order.

[0334] In some embodiments, the stacked solar cell includes a first electrode, an optional first blocking layer, an optional first charge transport layer, a first light absorbing layer, an optional second charge transport layer, an optional second blocking layer, a connecting layer, an optional third blocking layer, an optional third charge transport layer, a second light absorbing layer, an optional fourth charge transport layer, an optional fourth blocking layer, and a second electrode.

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

[0336] In some embodiments, the stacked 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.

[0337] As an example, the stacked solar cell includes a substrate, a first electrode, a first charge transport layer, a first blocking layer, a first light absorbing layer, a second blocking layer, a second charge transport layer, a connecting layer, a third charge transport layer, a third blocking layer, a second light absorbing layer, a fourth blocking layer, a fourth charge transport layer, and a second electrode.

[0338] In some embodiments, the stacked solar cell includes a first electrode, an optional first blocking layer, 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, an optional second blocking layer, a connecting layer, an optional third blocking 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, an optional fourth blocking layer, and a second electrode.

[0339] As an example, the stacked solar cell includes a substrate, a first electrode, a first blocking layer, a first charge transport layer, a first blocking layer, a first light absorbing layer, a second blocking layer, a second charge transport layer, a second blocking layer, a connecting layer, a third blocking layer, a third charge transport layer, a third blocking layer, a second light absorbing layer, a fourth blocking layer, a fourth charge transport layer, a fourth blocking layer, and a second electrode.

[0340] In some embodiments, the stacked solar cell includes a first electrode, an optional first blocking 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 blocking layer, and a second electrode, stacked in order. Optionally, one or more of the 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 is also provided with a blocking layer.

[0341] As an example, the stacked solar cell includes a substrate, a first electrode, a first blocking layer, a first charge transport layer, a first passivation layer, a first light absorbing 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 absorbing layer, a fourth passivation layer, a fourth charge transport layer, a fourth blocking layer, and a second electrode, stacked in order. Optionally, one or more of the 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 is also provided with a blocking layer.

[0342] In some embodiments, the stacked solar cell includes a first electrode, 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, an optional second blocking layer, a connecting layer, an optional third blocking 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, and a second electrode, stacked in order.

[0343] As an example, the stacked solar cell includes a substrate, a first electrode, a first charge transport layer, a first passivation layer, a first light absorbing layer, a second passivation layer, a second charge transport layer, a second blocking layer, a connecting layer, a third blocking layer, a third charge transport layer, a third passivation layer, a second light absorbing layer, a fourth passivation layer, a fourth charge transport layer, and a second electrode, stacked in order.

[0344] In some embodiments, the stacked solar cell includes a first electrode, an optional first blocking 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, an optional second blocking layer, a connecting layer, an optional third blocking 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 blocking layer, and a second electrode, stacked in order.

[0345] As an example, the 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 absorbing 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 absorbing layer, a fourth passivation layer, a fourth charge transport layer, a fourth barrier layer, and a second electrode, which are stacked.

[0346] In some embodiments, the stacked 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 absorbing 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 absorbing layer, an optional fourth passivation layer, an optional fourth barrier layer, an optional fourth charge transport layer, and a second electrode, which are stacked.

[0347] As an example, the 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 absorbing 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 absorbing layer, a fourth passivation layer, a fourth barrier layer, a fourth charge transport layer, and a second electrode, which are stacked.

[0348] Understandably, in the stacked solar cell, one or more of the first barrier layer, the second barrier layer, the third barrier layer, and the fourth barrier layer can be included.

[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 stacked 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] One of the first charge injection layer and the second charge injection layer is an electron injection layer, and the other is a hole injection layer. When the first charge transport layer is an electron transport layer, the first charge injection layer is an electron injection layer. The electron injection layer can facilitate efficient injection of electrons into the electron transport layer. When the first charge transport layer is a hole transport layer, the first charge injection layer is a hole injection layer. The hole injection layer can facilitate 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, the third charge injection layer being disposed between the connecting layer and the third charge transport layer.

[0353] In some embodiments, the tandem solar cell further comprises a fourth charge injection layer and a fourth charge transport layer, 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 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 comprises a third charge injection layer and a third charge transport layer, the third charge transport layer is an electron transport layer, and the third charge injection layer is an electron injection layer. The electron injection layer can facilitate efficient injection of electrons into the electron transport layer. As an example, the tandem solar cell further comprises a third charge injection layer and a third charge transport layer, the third charge transport layer is a hole transport layer, and the third charge injection layer is a hole injection layer. The hole injection layer can facilitate efficient injection of holes into the hole transport layer.

[0356] As an example, the tandem solar cell further comprises a fourth charge injection layer and a fourth charge transport layer, the fourth charge transport layer is an electron transport layer, and the fourth charge injection layer is an electron injection layer. The electron injection layer can facilitate efficient injection of electrons into the electron transport layer. As an example, the tandem solar cell further comprises a fourth charge injection layer and a fourth charge transport layer, the fourth charge transport layer is a hole transport layer, and the fourth charge injection layer is a hole injection layer. The hole injection layer can facilitate efficient injection of holes into the hole transport layer.

[0357] Further, the material of the electron injection layer comprises one or more of zinc oxide (ZnO), titanium oxide (TiO2), cesium fluoride (CsF), LiF, Li2O, fullerene and its derivatives, carbon nanotube (CNT) and graphene.

[0358] Further, the material of the hole injection layer comprises but is not limited to tetrafluoro tetracyanoquinodimethane, N,N'-bis[4-di(m-tolyl)aminophenyl]-N,N'-diphenylbenzidine, tungsten oxide (WO 3-x ), CD2, C is one or more of Cr or Mo; D is one or more of O, S, Se and Te.

[0359] In some embodiments, the tandem solar cell comprises a first electrode, an optional first charge injection layer, an optional first charge transport layer, a first light absorbing 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 absorbing layer, an optional fourth charge transport layer, an optional fourth charge injection layer and a second electrode, which are stacked.

[0360] Referring to FIG. 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 absorbing layer 110, a second charge transport layer 320, a second charge injection layer 720, a connection layer 900, a third charge injection layer 730, a third charge transport layer 330, a second light absorbing layer 120, a fourth charge transport layer 340, a fourth charge injection layer 740, and a second electrode 220, which are stacked.

[0361] In some embodiments, the stacked 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 absorbing layer, an optional second passivation layer, an optional second charge transport layer, an optional second charge injection layer, a connection layer, an optional third charge injection 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 charge injection layer, and a second electrode, which are stacked.

[0362] As an example, the 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 absorbing layer, a second passivation layer, a second charge transport layer, a second charge injection layer, a connection layer, a third charge injection layer, a third charge transport layer, a third passivation layer, a second light absorbing layer, a fourth passivation layer, a fourth charge transport layer, a fourth charge injection layer, and a second electrode, which are stacked.

[0363] In some embodiments, the stacked 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 absorbing layer, an optional second passivation layer, an optional second charge transport layer, an optional second charge injection layer, a connection layer, an optional third charge injection 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 charge injection layer, and a second electrode, which are stacked.

[0364] As an example, the 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 absorbing layer, a second passivation layer, a second charge transport layer, a second charge injection layer, a connection layer, a third charge injection layer, a third charge transport layer, a third passivation layer, a second light absorbing layer, a fourth passivation layer, a fourth charge transport layer, a fourth charge injection layer, and a second electrode, which are stacked.

[0365] Understandably, one or more of the above-mentioned charge transport layers, passivation layers, blocking layers, and charge injection layers can be arbitrarily combined with each other on the basis of not contradicting each other to form a combined technical solution, all within the scope of the technical solutions of the present application.

[0366] In some embodiments, the material of the first electrode, the second electrode, the third electrode, and the fourth electrode each independently includes one or more of an inorganic conductive material, an organic conductive material, and an organic-inorganic hybrid conductive material.

[0367] As an example, the inorganic conductive material includes one or more of a carbon material, a metal material and an alloy thereof, and a conductive metal oxide.

[0368] Further, the carbon material includes but is not limited to one or more of graphite, graphene, and carbon nanotubes.

[0369] Further, the conductive metal oxide includes a transparent conductive metal oxide.

[0370] Further, the metal material in the metal material and the alloy thereof includes 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 an example, the organic conductive material includes one or more of polyacrylic acid, polyimide (PI), polyaniline (PANI), polythiophene (PT) and derivatives thereof, and polypyrrole. The polythiophene (PT) and derivatives thereof include but are not limited to poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS).

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

[0373] The material of the light-transmitting electrode includes but is not limited to a transparent conductive metal oxide. As an example, the material of the light-transmitting electrode can include but is 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), and the like transparent conductive metal oxide.

[0374] Further, the solar cell further comprises a substrate, and the first electrode is disposed on the substrate. The substrate can be glass, so that the substrate and the first electrode material form transparent conductive glass. The transparent conductive glass can be, for example, FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), lanthanide metal-doped indium oxide, antimony-doped tin oxide, gallium zinc oxide (GZO), indium tungsten oxide (IWO), and the like.

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

[0376] When one of the electrodes is a light-transmitting electrode, the other electrode can be a light-transmitting electrode or a non-light-transmitting electrode. If the other electrode is a non-light-transmitting electrode, the material thereof includes, but is not limited to, an organic material, or an inorganic material, or a conductive material mixed in different proportions from both organic and inorganic materials. Further, the inorganic material includes a metal material, and the corresponding electrode is a metal electrode.

[0377] The above-mentioned electrode layer, hole transport layer, electron transport layer, barrier layer, injection layer, light absorption layer, and the like can be prepared by using a preparation method commonly used in the art, including but not limited to one or more of coating and deposition methods.

[0378] Further, the coating method includes, but is not limited to, one or more of spin coating, spraying, brushing, rubbing, screen printing, gravure coating, blade coating, and slot coating. Further, according to the precursor used in the coating method, it includes, but is not limited to, one or more of sol-gel method and solution method.

[0379] Further, the deposition method includes, but is not limited to, one or more of vacuum evaporation, sputtering deposition, plasma deposition, ion deposition, atomic layer deposition, and vacuum flash evaporation.

[0380] For example, the tin dioxide electron transport layer can be prepared by using atomic layer deposition technology (ALD); the organic electron transport layer such as [6,6]-phenyl C61 butyric acid methyl ester can be prepared by vacuum evaporation;

[0381] For example, the perovskite layer can be prepared by using vacuum flash evaporation (VCD), vacuum evaporation, multi-source co-evaporation, and the like; the perovskite layer can also be prepared by using a coating method.

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

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

[0384] The solution method includes spin coating, spraying, blade coating and slot coating, etc., and the solid deposition method includes vacuum evaporation, sputtering deposition, plasma deposition, ion deposition, etc.

[0385] It can be understood that the structure of the stacked solar cell involved in the present application can not be limited to the structure layers listed above. Other functional layers such as buffer layers can also be introduced according to requirements.

[0386] In some embodiments, the direction of the structure layer stack of the stacked solar cell is the thickness direction, which can be referred to as the first direction, and can also refer to the Y direction in FIG. 7.

[0387] Referring to FIG. 7, the first cell unit and the second cell unit in the stacked solar cell 10 are both provided with P1 channels, P2 channels and P3 channels. The P1 channels, P2 channels and P3 channels are etching regions arranged across layers, used to divide the large-area film layer of the first cell unit or the second cell unit into multiple sub-cells, and to form a series structure of the multiple sub-cells in the first cell unit or the second cell unit, so as to improve the output voltage and power. The P1, P2 and P3 are respectively used to connect the structure layers arranged at intervals, so that the structure layer between the first electrode of one sub-cell and the second electrode of another sub-cell constitutes a path, and the cell unit forms a battery assembly.

[0388] The P1 channels, P2 channels and P3 channels can each independently be a linear etching region, also referred to as an etching line. The P1 channels, P2 channels and P3 channels can each independently be a laser etching region. The number of P1 channels, P2 channels and P3 channels can each independently be one or more.

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

[0390] It can be understood that the height of each channel is determined according to the thickness of the structure 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 stacked solar cell.

[0391] In some embodiments, the first cell in the stacked solar cell 10 shown in FIG. 7 is provided as an example to illustrate the P1 channel, P2 channel and P3 channel structures thereof.

[0392] For a two-terminal stacked solar cell, the P2 channel and the P3 channel are simultaneously used to scribe and separate the film layers of the first cell and the second cell. As an example, for a two-terminal stacked solar cell, the P1 channel is formed on the first electrode first, then the first cell and the second cell are prepared on the first electrode, the P2 channel is formed before the second electrode is prepared; and then the P3 channel is formed after the second electrode is formed.

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

[0394] The first cell includes, in sequence along the Y direction, 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. The solar cell 10 is provided with a P1 channel for separating the first electrode 210, a P2 channel for separating the first charge transport layer 310, the first light absorption layer 110 and the second charge transport layer 320, and a P3 channel for separating the third electrode 230.

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

[0396] The P2 channel separates the light absorption layer along the thickness direction Y of the solar cell and exposes the first electrode. The P2 channel is filled with a material of the third electrode or other conductive material to connect the first electrode and the third electrode of adjacent sub-cells.

[0397] The P3 channel separates the third electrode along the thickness direction Y of the solar cell, thereby forming a plurality of sub-cells, so that the third electrodes of adjacent two sub-cells in the X direction are not connected to each other to achieve insulation. Through the channels, the division and connection of the sub-cells in the solar cell can be achieved.

[0398] The channels in the stacked solar cell 10 separate the cell units in the solar cell 10 into a plurality of sub-cells, each of which includes a P1 channel, a P2 channel and a P3 channel, and the P1 channel, the P2 channel and the P3 channel in each sub-cell are arranged in sequence along the X direction.

[0399] Each sub-cell includes an active region 11 and three channel-surrounded dead regions 12. The active region 11 refers to a region in a solar cell that can effectively absorb photons, generate photo-generated carriers (electrons and holes), and achieve charge separation and transport, corresponding to the region between the directly adjacent P3 channel and P1 channel, where the P3 channel and P1 channel are directly adjacent, meaning that no P2 channel is arranged between the two.

[0400] In the solar cell 10 shown in FIG. 7, the P1 channel penetrates 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 penetrates 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; and the P3 channel penetrates 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 side surface of the first electrode 210, where the outer side surface of the first electrode 210 refers to the side surface of the first electrode 210 facing the first light absorption layer 110.

[0401] In the present application, "stacked" means that two adjacent structure layers defined are arranged adjacent to each other, and the two adjacent structure layers can be in direct contact; it can be understood that an unavoidable transition layer can be formed during the process of combining the two adjacent structure layers.

[0402] An embodiment of the present application also provides a photovoltaic module, which includes the above-mentioned solar cell.

[0403] The above-mentioned solar cell has good stability, and can improve the stability and photoelectric conversion efficiency of the photovoltaic module.

[0404] In the above-mentioned photovoltaic module, one or more of the above-mentioned solar cells are included, which can be selected according to specific application scenarios; further, the above-mentioned photovoltaic module includes a plurality of the above-mentioned solar cells, which are connected in series or in parallel to form a cell piece. Further, the above-mentioned photovoltaic module can further include a stacked cell, which includes one or more of the above-mentioned solar cells.

[0405] In some embodiments, the above-mentioned photovoltaic module further includes a photovoltaic glass layer, an adhesive layer, and a back plate.

[0406] The two surfaces of the cell piece are respectively provided with an adhesive layer, a back plate is arranged on the surface away from the cell piece in one of the adhesive layers, and a photovoltaic glass layer is arranged on the surface away from the cell piece in the other adhesive layer.

[0407] The photovoltaic glass layer and the back plate are used for protecting the solar cell, and have the functions of sealing, insulation and waterproofing; the adhesive layer is used for bonding the photovoltaic glass layer and the solar cell and bonding the back plate and the solar cell.

[0408] Non-limitingly, the material of the photovoltaic glass layer can be tempered glass, the material of the back plate can be TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the material of the adhesive layer can be EVA (polyethylene-polyvinyl acetate copolymer).

[0409] Further, the photovoltaic module further comprises a junction box and a frame.

[0410] The junction box is used for protecting the power generation system of the entire photovoltaic module, and is equivalent to a current transfer station. When a short circuit occurs in the solar cell, the junction box automatically disconnects the short-circuited cell string.

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

[0412] Further, the connection between the frame and other parts of the photovoltaic module is bonded and sealed by silicone. The photovoltaic module can convert solar energy into electrical energy, which can be stored in a storage battery or used to drive a load.

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

[0414] An embodiment of the present application also provides a photovoltaic system comprising the photovoltaic module.

[0415] The photovoltaic system uses the photovoltaic effect of the solar cell in the photovoltaic module to directly convert solar radiation energy into electrical energy, and has high stability and efficiency.

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

[0417] The photovoltaic module is the core part of the photovoltaic power generation system. In the photovoltaic system, one or more photovoltaic modules are included, which can be selected according to the specific application scenario. Further, when the photovoltaic system includes a plurality of photovoltaic modules, the plurality of photovoltaic modules form a photovoltaic array.

[0418] The photovoltaic system can be an independent photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0419] The stand-alone photovoltaic power generation system includes a photovoltaic array, a battery pack, a charge controller, a power electronic converter (inverter), a load, etc. The working principle is that solar radiation energy is first converted into electric energy by the photovoltaic array, and then converted by the power electronic converter to supply power to the load. At the same time, the excess electric energy is stored in the energy storage device in the form of chemical energy through the charge controller. Thus, when the sunlight is insufficient, the energy stored in the battery can be converted into AC 220V, 50Hz electric energy through the power electronic inverter, filtering, and power transformer to supply the AC load.

[0420] The grid-connected photovoltaic power generation system includes a photovoltaic array, a high-frequency DC / DC booster circuit, a power electronic converter (inverter), and system monitoring. The working principle is that solar radiation energy is converted by the photovoltaic array, and then converted into high-voltage DC through the high-frequency DC / DC booster circuit. Then, the high-voltage DC is inverted by the power electronic inverter to output a sinusoidal AC current consistent with the grid voltage and frequency to the grid.

[0421] The above two photovoltaic power generation systems have their own characteristics, and can be selected according to specific application scenarios.

[0422] An embodiment of the present application provides a power utilization device, which includes one or more of the above-mentioned solar cells and the above-mentioned photovoltaic modules.

[0423] In some embodiments, the above-mentioned solar cells or photovoltaic modules can be used as a power supply of the power utilization device, and can also be used as an energy storage unit of the power utilization device.

[0424] Further, the power utilization device can include a mobile device, such as an electric vehicle, an electric train, a ship, a satellite, etc., but is not limited thereto.

[0425] FIG. 8 is a power utilization device 20 as an example. The power utilization device 20 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0426] In some embodiments, the above-mentioned solar cells can be used as a power generation device of the power utilization device. The type of the power generation device can include, but is not limited to, integrated power generation. The position of the power generation device can include, but is not limited to, the roof of the car, the back plate, etc.

[0427] An embodiment of the present application provides a power generation device, which includes one or more of the above-mentioned solar cells and the above-mentioned photovoltaic modules.

[0428] Further, the power generation device is a photovoltaic photoelectric device.

[0429] In order to make the technical problems, technical solutions and beneficial effects solved in the present application clearer, the present application will be further described in detail below in conjunction with embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting on the application or its applications. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort fall within the scope of protection of the present application.

[0430] Unless specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in the art or according to the product manual are used. Unless the manufacturer of reagents or instruments is specified, all the reagents or instruments used are conventional products that can be commercially available.

[0431] Embodiment 1

[0432] The preparation of the two-end laminated solar cell comprises the following steps:

[0433] 1. First electrode: Take FTO conductive glass with a size of 2.0*2.0 cm, remove 0.35 cm of FTO at both ends by laser etching, and expose the glass substrate; clean the etched FTO conductive glass with cleaning solution, deionized water and ethanol successively; dry the solvent under a nitrogen gun, and further clean in a UV-ozone machine.

[0434] 2. First charge transport layer (hole transport layer): After UV-ozone treatment, spin-coat 15 mg / mL NiOx(1≤x≤2) nanoparticle aqueous solution on the FTO conductive glass at a speed of 2000 rpm / s in a glove box to form a first charge transport layer with a thickness of 30 nm, and then perform heat annealing treatment at 150°C for 10 min.

[0435] 3. First light absorbing layer: Add 0.903 0.65 mmol of FAI, 0.147 0.39 mmol of FABr, 0.301 0.13 mmol of CsI, 0.049 0.13 mmol of CsBr, 1.204 0.78 mmol of PbI2 and 0.196 0.52 mmol of PbBr2 into 1 mL of mixed solvent of DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide) (the volume ratio of DMF to DMSO is 4:1), stir at a speed of 600 rpm on a magnetic stirrer for 8 h, and filter to prepare a perovskite precursor solution.

[0436] 100 μL of the above perovskite precursor solution was spin-coated onto the first charge transport layer, and the spin-coating process was as follows: first, spin-coating at a spin speed of 2000 rpm and an acceleration of 200 rpm / s for 10 s, then spin-coating at a spin speed of 4000 rpm and an acceleration of 1000 rpm / s for 25 s, then adding 200 μL of chlorobenzene dropwise to the spin-coated perovskite precursor solution, followed by spin-coating the perovskite precursor solution again (spin speed of 4000 rpm and spin-coating time of 15 s), and then transferring to a hot stage for annealing at 100°C for 15 min to form a first light-absorbing layer.

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

[0438] 5. Composite layer: ITO film was first spin-coated on the second charge transport layer, and the spin-coating process was as follows: first, spin-coating at a low speed of 350 rpm for 9-2 s, then increasing the spin speed to 4000 rpm and spin-coating for 40 s, and then placing it on a hot stage for annealing at 100°C for 10 min.

[0439] 6. Third charge transport layer (hole transport layer): Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid) (PEDOT:PSS) was spin-coated on the above composite layer (spin speed of 4000 rpm and spin-coating time of 30 s), and then transferred to a hot stage for annealing at 150°C for 10 min to form a 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, stirred on a magnetic stirrer at a speed of 600 rpm for 2 h, filtered, and a silver bismuth sulfide precursor solution was prepared. 100 μL of the above silver bismuth sulfide precursor solution was spin-coated onto the above third charge transport layer, first at a spin speed of 6000 rpm for 60 s, and then transferred to a hot stage for annealing at 150°C for 10 min to form a second light-absorbing layer with a thickness of 50 nm.

[0441] 8. Fourth charge transport layer (electron transport layer): A layer of C60 with a thickness of 20 nm was evaporated on the above second light-absorbing layer to form a fourth charge transport layer.

[0442] 9. Second electrode (back electrode layer): A layer of copper (Cu) with a thickness of 100 nm was evaporated on the above fourth charge transport layer to form a back electrode layer. A two-terminal tandem solar cell was prepared.

[0443] Example 2

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

[0445] The difference between the embodiment 1 and the embodiment 2 is that the material of the (6) connecting layer is different, and the (6) connecting layer is an insulating layer. The insulating layer is transparent glass. In addition, the embodiment 2 further comprises the steps of transferring the insulating layer into a magnetron sputtering cabin, and depositing an ITO layer on each of the two opposite surfaces of the insulating layer.

[0446] The ITO layers on the two sides of the insulating layer are respectively used as the third electrode and the fourth electrode.

[0447] The photoelectric conversion efficiency and the stability of the stacked solar cell device are tested.

[0448] (1) The photoelectric conversion efficiency of the stacked solar cell device is tested. The testing method is as follows:

[0449] The battery performance is tested by using a Keithley 2400 SMU under the light source of 100 mW / cm 2 , and the photoelectric conversion efficiency is obtained. The photoelectric conversion efficiency PCE is calculated by the following parameters: PCE = Pout / Popt = Voc x Jsc x (Vmpp x Jmpp) / (Voc x Jsc) / Popt = Voc x Jsc x FF / Popt

[0450] , wherein Pout, Popt, Vmpp, Jmpp, Voc and Jsc are the working output power of the battery, the incident light power, the maximum power point voltage of the battery, the maximum power point current of the battery, the open circuit voltage and the short circuit current, respectively. FF is the fill factor.

[0451] (2) The stability of the stacked solar cell device is tested. The testing method is as follows:

[0452] The stacked solar cell is placed under the light source of 100 mW / cm 2 at 65°C, and the change of the photoelectric conversion efficiency with the aging time is tracked. The time required for the photoelectric conversion efficiency to decay to 80% of the initial efficiency is recorded as T80, and the size of the parameter represents the stability of the stacked solar cell.

[0453] The stacked solar cell prepared by the above embodiment comprises the silver bismuth sulfide ore type material thin film AgBiS2. Since the silver bismuth sulfide ore type material has good thermal stability, and the stacked solar cell can effectively utilize solar energy, the stacked solar cell has good device stability in the long-term working process, and provides good photoelectric conversion efficiency.

[0454] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, it is to be understood that the application encompasses all such possible combinations.

[0455] The above-described embodiments only express several implementation manners of the application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the application, and these all belong to the protection scope of the application. Therefore, the patent protection scope of the application should be subject to the appended claims, and the description and drawings can be used to explain the scope of the claims.

Claims

1. A stacked solar cell, comprising: a first cell unit comprising a first light-absorbing layer; a second cell unit comprising a second light-absorbing layer, the second light-absorbing layer comprising a silver bismuth sulfide mineral type material; and a connecting layer disposed between and connecting the first cell unit and the second cell unit; wherein the first light-absorbing layer has a band gap greater than the band gap of the second light-absorbing layer. The silver bismuth sulfide mineral type material comprises one or more of a cubic rock salt phase crystal form and a hexagonal phase crystal form.

2. The tandem solar cell of claim 1, wherein, The silver bismuth sulfide mineral type material has a grain size of 10 nm or more, optionally 10 nm to 10 μm, more optionally 10 nm to 500 nm or 50 nm to 200 nm.

3. The tandem solar cell of any of claims 1 to 2, wherein, The silver bismuth sulfide mineral type material comprises one or both of a polycrystal and a single crystal.

4. The solar cell of any one of claims 1 to 3, wherein, The silver bismuth sulfide mineral type material has a band gap of 0.8 eV to 1.4 eV, optionally 0.8 eV to 1.2 eV, more optionally 0.9 eV to 1.1 eV.

5. The tandem solar cell according to any one of claims 1 to 4, wherein, The first light-absorbing layer has a band gap of 1.5 eV to 1.9 eV, optionally 1.53 eV to 1.65 eV.

6. The tandem solar cell according to any one of claims 1 to 5, wherein The first light-absorbing layer has a thickness of 200 nm to 1000 nm, optionally 400 nm to 600 nm.

7. The tandem solar cell according to any one of claims 1 to 6, wherein The second light-absorbing layer has a thickness of 10 nm to 20 μm, optionally 10 nm to 10 μm, more optionally 30 nm to 500 nm or 50 nm to 200 nm.

8. The tandem solar cell according to any one of claims 1 to 7, wherein The stacked solar cell comprises:

9. The tandem solar cell according to any one of claims 1 to 8, wherein, a first electrode and a second electrode; wherein the first cell unit comprises the first electrode, the first electrode being disposed on a side of the first light-absorbing layer distal to the connecting layer, and the second cell unit comprises the second electrode, the second electrode being disposed on a side of the second light-absorbing layer distal to the connecting layer. The first cell unit further comprises one or both of a first charge transport layer and a second charge transport layer; 10. The tandem solar cell of claim 9, wherein, The first charge transport layer is located between the first electrode and the first light-absorbing layer; The second charge transport layer is located between the first light-absorbing layer and the connecting layer; wherein 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. The second cell unit further comprises one or both of a third charge transport layer and a fourth charge transport layer; 11. The tandem solar cell of any of claims 9 to 10, wherein, The third charge transport layer is located between the connecting layer and the second light-absorbing layer; The fourth charge transport layer is located between the second light-absorbing layer and the second electrode; wherein 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. The electron transport layer comprises one or more of the following materials and derivatives, dopants and passivated materials thereof:

12. The tandem solar cell of any of claims 10 to 11, wherein, [6,6]-phenyl C61 butyric acid methyl ester, [6,6]-phenyl C71 butyric acid methyl ester, fullerene C61, fullerene C60, fullerene C70, tin dioxide, zinc oxide, perylene imide materials and naphthalene imide materials. The electron transport layer has a thickness of 1 nm to 300 nm, optionally 1 nm to 100 nm.

13. The tandem solar cell of any of claims 10 to 12, wherein, ​ 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 derivatives, dopants and passivated materials thereof: Nickel oxide, molybdenum oxide, molybdenum sulfide, cuprous oxide, cuprous iodide, cuprous thiocyanate, 2,2',7,7'-tetrakis(N,N-p-methylanilino)-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, poly-3-hexylthiophene, methoxyphenylamine-fluoromethylformamide, triphenylamine with a core of triptycene, 3,4-ethylenedioxythiophene-methoxyphenylamine, N-4-aniline carbazole-spirofluorene, polythiophene and self-assembled monomolecular material.

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

16. The tandem solar cell of any one of claims 9 to 15, wherein, One or more of the following conditions are met: (1) The first battery unit further comprises a first passivation layer, which is arranged on the side of the first light absorbing layer facing the first electrode, and optionally, the first passivation layer is arranged on at least part of the surface of the first light absorbing layer facing the first electrode; (2) The first battery unit further comprises a second passivation layer, which is arranged on the side of the first light absorbing layer facing the connecting layer, and optionally, the second passivation layer is arranged on at least part of the surface of the first light absorbing layer facing the connecting layer; (3) The second battery unit further comprises a third passivation layer, which is arranged on the side of the second light absorbing layer facing the connecting layer, and optionally, the third passivation layer is arranged on at least part of the surface of the second light absorbing layer facing the connecting layer; (4) The second battery unit further comprises a fourth passivation layer, which is arranged on the side of the second light absorbing layer facing the second electrode, and optionally, the fourth passivation layer is arranged on at least part of the surface of the second light absorbing layer facing the second electrode. One or more of the following conditions are met:

17. The tandem solar cell of any of claims 9 to 16, wherein, (1) The first battery unit comprises a first passivation layer and a first charge transport layer, and the first passivation layer is arranged between the first charge transport layer and the first light absorbing layer; (2) The first battery unit comprises a second passivation layer and a second charge transport layer, and the second passivation layer is arranged between the first light absorbing layer and the second charge transport layer; (3) The second battery unit comprises a third passivation layer and a third charge transport layer, and the third passivation layer is arranged between the third charge transport layer and the second light absorbing layer; (4) The second battery unit comprises a fourth passivation layer and a fourth charge transport layer, and the fourth passivation layer is arranged between the second light absorbing layer and the fourth charge transport layer. One or more of the following conditions are met:

18. The tandem solar cell of claim 16 or 17, wherein, (1) The first battery unit comprises a first passivation layer, and the thickness of the first passivation layer is 1 nm to 20 nm; (2) The first battery unit comprises a second passivation layer, and the thickness of the second passivation layer is 1 nm to 20 nm; (3) The second battery unit comprises a third passivation layer, and the thickness of the third passivation layer is 1 nm to 20 nm; ​ (4) the second battery unit comprises a fourth passivation layer, and a thickness of the fourth passivation layer is 1 nm to 20 nm.

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

20. The tandem solar cell of any of claims 17 to 19, wherein, one or more of the following conditions is met: (1) the first battery unit further comprises a first barrier layer, and the first barrier layer is arranged between the first electrode and the first light-absorbing layer; (2) the first battery unit further comprises a second barrier layer, and the second barrier layer is arranged between the first light-absorbing layer and the connecting layer; (3) the second battery unit further comprises a third barrier layer, and the third barrier layer is arranged between the connecting layer and the second light-absorbing layer; (4) the second battery unit further comprises a fourth barrier layer, and the fourth barrier layer is arranged between the second light-absorbing layer and the second electrode; wherein one of the first barrier layer and the second barrier layer is an electron barrier layer, and the other is a hole barrier layer; one of the third barrier layer and the fourth barrier layer is an electron barrier layer, and the other is a hole barrier layer.

21. The laminated solar cell of claim 20, wherein, one or more of the following conditions is met: (1) the first battery unit comprises a first barrier layer and a first charge transport layer; optionally, the first barrier layer is arranged between the first electrode and the first charge transport layer; optionally, the first barrier layer is arranged between the first charge transport layer and the first light-absorbing layer; (2) the first battery unit further comprises a second barrier layer and a second charge transport layer; optionally, the second barrier layer is arranged between the second charge transport layer and the connecting layer; optionally, the second barrier layer is arranged between the first light-absorbing layer and the second charge transport layer; (3) the second battery unit further comprises a third barrier layer and a third charge transport layer; optionally, the third barrier layer is arranged between the connecting layer and the third charge transport layer; optionally, the third barrier layer is arranged between the third charge transport layer and the second light-absorbing layer; (4) the second battery unit further comprises a fourth barrier layer and a fourth charge transport layer; optionally, the fourth barrier layer is arranged between the fourth charge transport layer and the connecting layer; optionally, the fourth barrier layer is arranged between the second light-absorbing layer and the fourth charge transport layer.

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

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

24. The tandem solar cell of any of claims 20 to 23, wherein, The thickness of the first blocking layer and the second blocking layer is independently 0.5nm-50nm.

25. The tandem solar cell of any of claims 9 to 24, wherein, The stacked solar cell comprises the first electrode, the first charge transport layer, the first light absorbing layer, the second charge transport layer, the connecting layer, the third charge transport layer, the second light absorbing layer, the fourth charge transport layer and the second electrode which are stacked. Optionally, the stacked solar cell comprises the first electrode, the first blocking layer, the first charge transport layer, the first passivation layer, the first light absorbing layer, the second passivation layer, the second charge transport layer, the connecting layer, the third charge transport layer, the third passivation layer, the second light absorbing layer, the fourth passivation layer, the fourth charge transport layer, the fourth blocking layer and the second electrode which are stacked.

26. The tandem solar cell of any of claims 9 to 25, wherein, The material of the first electrode and the second electrode independently comprises one or more of organic conductive material, inorganic conductive material and organic-inorganic hybrid conductive material.

27. The laminated solar cell of claim 26, wherein, One or more of the following conditions are met: (1) the inorganic conductive material comprises one or more of carbon material, metal material and its alloy, and transparent conductive metal oxide; (2) the organic conductive material comprises one or more of polyacrylic acid, polyimide, polyaniline, polythiophene and its derivative, and polypyrrole.

28. The tandem solar cell of any 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 of any of claims 9 to 28, wherein, The stacked solar cell comprises the first electrode, the first charge transport layer, the first light absorbing layer, the second charge transport layer, the connecting layer, the third charge transport layer, the second light absorbing layer, the fourth charge transport layer and the second electrode which are stacked. The band gap of the first light absorbing layer is greater than the band gap of the second light absorbing layer, and the first electrode is a light-transmitting electrode. 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 laminated solar cell of any one of claims 25 or 29, wherein, The connecting layer comprises a composite layer. 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 laminated solar cell of claim 30, wherein, The material of the composite layer comprises one or more of metal material, transparent conductive oxide and carbon material.

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

33. The tandem solar cell of any of claims 30 to 32, wherein, The thickness of the composite layer is 0.1nm-200nm, and is optionally 0.5nm-10nm.

34. The tandem solar cell as claimed in any one of claims 9 to 29, wherein, The stacked solar cell further comprises a third electrode and a fourth electrode, the connecting layer comprises an insulating layer, the third electrode is arranged between the first light-absorbing layer and the connecting layer, and the fourth electrode is arranged 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 comprises the first electrode, a first charge transport layer, the first light-absorbing layer, a second charge transport layer, the third electrode, the connecting layer, the fourth electrode, a third charge transport layer, the second light-absorbing layer, a fourth charge transport layer, and the second electrode which are arranged in a stack; more optionally, 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 as claimed in any one of claims 9 to 29, wherein, The stacked solar cell comprises a first electrode, a first light-absorbing layer, a shared fifth electrode, a second light-absorbing layer, and a second electrode which are arranged in a stack.

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

37. The laminated solar cell of claim 36, wherein, The divalent anion comprises one or more of a divalent inorganic anion and a divalent organic anion.

38. The tandem solar cell of claim 37, wherein, The divalent inorganic anion comprises one or more of O 2- , S 2- , Se 2- , and Te 2- ; optionally comprising S 2- .

39. The tandem solar cell of any one of claims 36 to 38, wherein, M comprises one or more of a metal cation and an organic cation; Optionally, the metal cation comprises 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+ . Optionally, the organic cation comprises at least one of an organic amine ion, a formamidinium ion, and an imidazolium ion.

40. The laminated solar cell of claim 36, wherein, M comprises a first cation A and a second cation B which are different in element species; Optionally, the first cation A and the second cation B each independently comprise one or more of 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+ . Optionally, the first cation A comprises Ag + , Li + , Na + , K + , Rb + , and Cs + . Optionally, the second cation B comprises Bi 3+ .

41. The laminated solar cell of claim 40, wherein, The silver bismuth sulfide mineral type material includes a chemical formula of A x B y The compound of X2, wherein x and y are values such that A x B y The compound of X2 as a whole is electrically neutral.

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

43. The laminated solar cell of claim 36, wherein, The silver bismuth sulfide mineral type material includes a compound of the formula A x B y X' z X" 2-z where X includes a divalent anion X' and a divalent anion X", and z is 0 to 2.

44. The tandem solar cell of claim 43, wherein, The silver bismuth sulfide mineral type material comprises a compound of the formula ABX' z X" 2-z The first cation A is a monovalent cation, the second cation B is a trivalent cation, X comprises a divalent anion X' and a divalent anion X", and z is 0 to 2.

45. The tandem solar cell of claim 43 or 44, wherein, One or more of the following conditions are satisfied: (1) the element species of the divalent anion X’ is different from that of the divalent anion X’'; (2) X' is S 2- , z is not 0; (3) X" is selected from one or more of O 2- , Se 2- , and Te 2- .

46. The tandem solar cell of any one of claims 1 to 45, wherein, The silver bismuth sulfide mineral type materials include one or more of AgBiS2, AgBiS z O 2-z , AgBiS z Se 2-z , AgBiS z Te 2-z wherein z is 0-2.

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

48. The tandem solar cell of claim 47, wherein, The perovskite material comprises one or more of a compound having a chemical formula of A’B’Y3 and a compound having a chemical formula of A’2CDY6; wherein A’ comprises a monovalent cation, B’ comprises a divalent cation, C comprises a monovalent cation, D comprises a trivalent cation, and Y comprises a monovalent anion; 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, One or more of the following features are satisfied: (1) A’ comprises one or more of a monovalent metal cation and a monovalent organic cation; (2) B’ comprises one or more of a divalent metal cation and a divalent organic cation; (3) C comprises one or more of monovalent metal cations and monovalent organic cations; (4) D comprises one or more of trivalent metal cations and trivalent organic cations; (5) Y comprises one or more of monovalent inorganic anions and monovalent organic anions.

50. The tandem solar cell of claim 49, wherein, satisfies one or more of the following characteristics: (1) the monovalent metal cation in A' comprises one or more of Li + , Na + , K + , Rb + , and Cs + , and the monovalent organic cation comprises one or more of an organic amine ion, a formamidinium ion, and an imidazolium ion; (2) the divalent metal cations in B' comprise one or more of divalent cations of 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 cations in C include one or more of Cs + , Ag + , K + , and Rb + . (4) the trivalent metal cation in D comprises one or more of Bi 3+ , Ni 3+ , Fe 3+ , Sb 3+ , In 3+ , and Cu 3+ . (5) Y comprises one or more of halide and pseudohalide ions; optionally, Y comprises F - , Cl - , Br - , I - , CN - , CH3COO - , SCN - , BF4 - , SeCN - , PF6 - .

51. A photovoltaic module comprising the tandem solar cell of any one of claims 1-50.

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

53. An electrically powered device comprising one or more of the tandem solar cell of any one of claims 1-50 and the photovoltaic module of claim 51.

54. An electricity generating device comprising one or more of the tandem solar cell of any one of claims 1-50 and the photovoltaic module of claim 51.

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