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

Abstract

A tandem solar cell, a photovoltaic module, and an electric device. The tandem solar cell comprises a first electrode and a second electrode; at least a first battery unit and second battery unit which are arranged between the first electrode and the second electrode and arranged in sequence in a first direction; and a composite layer arranged between the first battery unit and the second battery unit, the first direction being an incident direction of light. The first battery unit comprises a first light absorption layer, a first electron transport layer, a first hole blocking layer arranged on the side of the first electron transport layer close to the first light absorption layer, and a second hole blocking layer arranged on the side of the first electron transport layer distant from the first light absorption layer, wherein the first light absorption layer, the first electron transport layer, the first hole blocking layer, and the second hole blocking layer are stacked, and the first light absorption layer comprises a perovskite material.

Description

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

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on and claims the priority of Chinese patent application with application number 202410206006.8, application date February 23, 2024, and invention name “Stacked solar cells, photovoltaic modules, power generation devices and power-using devices”. The entire content of the Chinese patent application is hereby incorporated into this disclosure as a reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a stacked solar cell, a photovoltaic module, a power generation device, and an electricity-consuming device. Background Art

[0004] Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric effect or photochemical effect. As an ideal renewable energy source, solar cells are receiving increasing attention.

[0005] With the development of solar cell technology, people have higher and higher requirements on the performance of solar cells. Tandem solar cells have good application prospects due to their high photoelectric conversion efficiency.

[0006] Tandem solar cells consist of at least two stacked cells. In each cell, the light-absorbing layer is in direct contact with the electron-transporting layer. When electrons and holes dissociated from the light-absorbing layer reach the electron-transporting layer, they undergo non-radiative recombination there, reducing the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell. Summary of the Invention

[0007] The present disclosure is made in response to the aforementioned challenges and aims to provide a tandem solar cell, photovoltaic module, power generation device, and power consumption device. By arranging a first hole blocking layer and a second hole blocking layer in the tandem solar cell, the tandem solar cell achieves multi-layer hole blocking in the first cell unit, enhancing the hole blocking effect and thereby improving the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0008] To achieve the above objectives, the present disclosure provides, in a first aspect, a tandem solar cell, comprising: a first electrode and a second electrode; at least a first cell unit and a second cell unit arranged in sequence along a first direction between the first electrode and the second electrode; and a recombination layer arranged between the first cell unit and the second cell unit, wherein the first direction is the incident direction of light; wherein the first cell unit comprises a stacked first light absorbing layer, a first electron transport layer, a first hole blocking layer arranged on a side of the first electron transport layer close to the first light absorbing layer, and a second hole blocking layer arranged on a side of the first electron transport layer away from the first light absorbing layer, wherein the first light absorbing layer comprises a perovskite material. By arranging the first hole blocking layer and the second hole blocking layer, multi-layer blocking of holes in the first cell unit can be achieved, thereby enhancing the hole blocking effect and further reducing the non-radiative recombination of holes and electrons, thereby improving the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0009] In some embodiments, the second battery cell includes a second light absorbing layer, a second electron transport layer, and a third hole blocking layer disposed between the second light absorbing layer and the second electron transport layer. The third hole blocking layer blocks holes, further reducing non-radiative recombination of electrons and holes.

[0010] In some embodiments, the first hole blocking layer includes a first hole blocking material, and the difference (σ) between the HOMO energy level of the first hole blocking material and the HOMO energy level of the perovskite material in the first light absorbing layer is less than or equal to -0.1 eV. σ within the above range can further enhance the hole blocking effect of the first hole blocking layer.

[0011] In some embodiments, the third hole-blocking layer includes a third hole-blocking material, the second light-absorbing layer includes a second light-absorbing material, and the difference (ω) between the HOMO energy level of the third hole-blocking material and the HOMO energy level of the second light-absorbing material is less than -0.1 eV. When ω is within the above range, the third hole-blocking layer further enhances its hole-blocking effect.

[0012] In some embodiments, the thickness of the first hole blocking layer is 5 nm to 20 nm. By controlling the thickness of the first hole blocking layer within the above range, the first hole blocking layer can play its hole blocking advantage while also reducing the absorption of sunlight by the first hole blocking layer.

[0013] In some embodiments, the thickness of the first hole blocking layer is 5 nm to 16 nm. By controlling the thickness of the first hole blocking layer, the advantages of the tandem solar cell can be further realized.

[0014] In some embodiments, the thickness of the third hole blocking layer is 5 nm to 20 nm. By controlling the thickness of the third hole blocking layer within the above range, the hole blocking advantage is brought into play while also helping to reduce the absorption of sunlight by the third hole blocking layer.

[0015] In some embodiments, the thickness of the third hole blocking layer is 5 nm to 10 nm. By controlling the thickness of the third hole blocking layer, the advantages of the tandem solar cell can be further realized.

[0016] In some embodiments, the first cell is disposed on the first electrode and includes a first hole transport layer, a first light absorbing layer, a first hole blocking layer, a first electron transport layer, and a second hole blocking layer, arranged sequentially along a first direction. The second cell is disposed on the composite layer and includes a second hole transport layer, a second light absorbing layer, a third hole blocking layer, and a second electron transport layer, arranged sequentially along the first direction. The second electrode is disposed on a side of the second electron transport layer away from the third hole blocking layer. The second light absorbing layer comprises a perovskite material. The arrangement of the first, second, and third hole blocking layers enables multi-layer hole blocking, enhancing the hole blocking effect and further improving the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0017] In some embodiments, a first cell is disposed on a first electrode and includes a first hole transport layer, a first light absorbing layer, a first hole blocking layer, a first electron transport layer, and a second hole blocking layer, arranged sequentially along a first direction. A second cell is disposed on a composite layer and includes a second hole transport layer, a second light absorbing layer, a third hole blocking layer, and a second electron transport layer, arranged sequentially along the first direction. The second cell further includes a fourth hole blocking layer disposed on a side of the second electron transport layer away from the third hole blocking layer and in contact with the second electron transport layer. The second electrode is disposed on a side of the fourth hole blocking layer away from the second electron transport layer. The second light absorbing layer comprises a perovskite material. By arranging the first, second, third, and fourth hole blocking layers, multi-layer hole blocking can be achieved, enhancing the hole blocking effect and further improving the open circuit voltage and photoelectric conversion efficiency of the tandem solar cell.

[0018] In some embodiments, the first battery cell is arranged on the first electrode and includes a second hole blocking layer, a first electron transport layer, a first hole blocking layer, a first light absorbing layer, and a first hole transport layer arranged in sequence along the first direction; the second battery cell is arranged on the composite layer and includes a second electron transport layer, a third hole blocking layer, a second light absorbing layer, and a second hole transport layer arranged in sequence along the first direction, and the second electrode is arranged on the second hole transport layer and in contact with the second hole transport layer; wherein the second light absorbing layer comprises crystalline silicon material.

[0019] In some embodiments, the first hole blocking layer includes 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, SnO2, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide, 2,7-bis(2,2'-bipyridin-5-yl)triphenylene, bis(8-hydroxy-2-methylquinoline At least one of )-(4-phenylphenoxy)aluminum, (6-(1,10-phenanthroline-3-yl)naphthalene-2-yl)diphenylphosphine oxide, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, and benzophenanthroline. The above materials can block the migration of holes.

[0020] In some embodiments, the second hole blocking material may include at least one of fullerene and its derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and SnO 2 , which can block the migration of holes.

[0021] In some embodiments, the third hole blocking layer includes 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, SnO2, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide, 2,7-bis(2,2'-bipyridin-5-yl)triphenylene, bis(8-hydroxy-2-methylquinolinol)-(4-phenylphenoxy)aluminum, (6-(1,10-phenanthroline-3- At least one of: (1,2-diphenyl)-2-naphthyl)-1,2,4-triazole, (2,4-diphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, (3,5-diphenyl-4-(1-naphthyl)-1,2,4-triazole, benzophenanthroline, copper phthalocyanine, 8-hydroxyquinoline-lithium, BN-ICz-1, and 2,7-bis[N-(m-tolyl)phenylamino]-9,9'-spirobi[9H-fluorene]. These materials can block the migration of holes.

[0022] In some embodiments, the HOMO energy level of the first light absorbing layer of the first cell is lower than the HOMO energy level of the second light absorbing layer of the second cell. This configuration facilitates the first cell and the second cell to form a tandem solar cell with high photoelectric conversion efficiency.

[0023] A second aspect of the present disclosure provides a photovoltaic module, which includes the stacked solar cell provided by the first aspect.

[0024] Since the photovoltaic module of the present disclosure includes the tandem solar cell provided by the present disclosure, it has at least the same advantages as the tandem solar cell.

[0025] A third aspect of the present disclosure provides a power generation device, which includes the stacked solar cell provided by the first aspect.

[0026] Since the power generation device of the present disclosure includes the tandem solar cell provided by the present disclosure, it has at least the same advantages as the tandem solar cell.

[0027] A fourth aspect of the present disclosure provides an electrical device, which includes the stacked solar cell provided in the first aspect.

[0028] Since the electric device of the present disclosure includes the tandem solar cell provided by the present disclosure, it has at least the same advantages as the tandem solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic structural diagram of a stacked solar cell according to an embodiment of the present disclosure.

[0030] FIG2 is a schematic structural diagram of an all-perovskite stacked cell according to an embodiment of the present disclosure.

[0031] FIG3 is a schematic structural diagram of an all-perovskite stacked cell according to an embodiment of the present disclosure.

[0032] FIG4 is a schematic structural diagram of a perovskite-crystalline silicon tandem cell according to an embodiment of the present disclosure.

[0033] Explanation of the figure marks: 10, 100, 200, 300 stacked solar cell; 11 first electrode; 12 second electrode; 13 first battery unit; 131 first hole transport layer; 132 first light absorption layer; 133 first hole blocking layer; 134 first electron transport layer; 135 second hole blocking layer; 14 second battery unit; 141 second hole transport layer; 142 second light absorption layer; 143 third hole blocking layer; 144 second electron transport layer; 145 fourth hole blocking layer; 15 composite layer. DETAILED DESCRIPTION

[0034] Below, with appropriate reference to the accompanying drawings, a detailed description of the embodiments of the laminated solar cell, photovoltaic module, power generation device, and power consumption device disclosed herein is specifically disclosed. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter described in the claims.

[0035] " scope " disclosed in the present disclosure is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and selected lower limit and upper limit define the boundary of special scope.The scope that this mode limits can be to include end value or not include end value, and can be combined arbitrarily, and promptly any lower limit can form a scope with any upper limit combination.For example, if the scope of 60-120 and 80-110 is listed for specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.In addition, if the minimum range value 1 and 2 listed, and if the maximum range value 3,4 and 5 listed, then the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.In the present disclosure, unless otherwise specified, numerical range " ab " represents the abbreviation of any real number combination between a and b, and wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Unless otherwise specified, all embodiments and optional embodiments of the present disclosure can be combined with each other to form new technical solutions.

[0037] Unless otherwise specified, all technical features and optional technical features disclosed herein can be combined with each other to form a new technical solution.

[0038] Unless otherwise specified, all steps of the present disclosure may be performed sequentially or randomly, preferably sequentially. For example, a method comprising steps (a) and (b) indicates that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, a method further comprising step (c) indicates that step (c) may be added to the method in any order, for example, the method may comprise steps (a), (b), and (c), or may comprise steps (a), (c), and (b), or may comprise steps (c), (a), and (b), etc.

[0039] Unless otherwise specified, the terms used in the present disclosure have the common meanings that are generally understood by those skilled in the art.

[0040] Unless otherwise specified, the numerical values ​​of the parameters mentioned in the present disclosure can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods given in the present disclosure.

[0041] As used herein, the term "layer" refers to any substantially layered structure. A layer may have a thickness that varies over the extent of the layer. Typically, a layer has an approximately constant thickness. As used herein, the term "thickness" of a layer refers to the average thickness of the layer. The thickness of a layer can be readily measured using conventional methods.

[0042] If not otherwise specified, reference in the present disclosure to a layer being on another layer includes the case where the first layer is directly on the second layer, i.e., the two layers are in direct contact, and the case where there are other layers (such as a third layer) interposed between the first and second layers.

[0043] The term "perovskite" as used in this disclosure refers to a material having a three-dimensional crystal structure related to the three-dimensional crystal structure of CaTiO3, or a layer material having a structure related to the structure of CaTiO3. Materials having a three-dimensional crystal structure related to CaTiO3 are well known and may be referred to as perovskites having a "3D perovskite structure", or as "3D perovskites". Materials comprising a layer of perovskite material are well known and are referred to in the art as "2D layered perovskites". When receiving sunlight, the electrons in the perovskite are excited, and the electrons jump from the valence band to the conduction band, generating electron-hole pairs. Unless otherwise specified, "perovskite" mentioned in this disclosure refers to 3D perovskite materials. The general chemical formula of perovskite can be expressed as ABX3, where A is generally a cation with a larger radius. For example, A includes: CH(NH2)2 + 、CH3NH3 + , K + , Rb + 、Cs + At least one of. B is a cation with a smaller radius, including but not limited to Pb 2+ 、Sn 2+ Mg 2+ , Ca 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Co 2+ , at least one of. X is an anion, for example, X includes: Cl - Br - , I -、SCN - 、CNO - 、OCN - 、OSCN - SH - OH - 、CP - 、CN - 、SeCN - When the perovskite includes more than one A cation, the different A cations may be distributed in an orderly or disordered manner on the A site. When the perovskite includes more than one B cation, the different B cations may be distributed in an orderly or disordered manner on the B site. When the perovskite includes more than one X anion, the different X anions may be distributed in an orderly or disordered manner on the X site.

[0044] Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric effect or photochemical effect. As an ideal renewable energy source, solar cells are gaining increasing attention.

[0045] With the advancement of solar cell technology, people are demanding increasingly higher performance from solar cells. Tandem solar cells consist of at least two stacked cells. By combining the band gaps of the cells, they absorb sunlight in the long-wavelength range, improving its utilization rate. Consequently, tandem solar cells achieve high photoelectric conversion efficiency.

[0046] Each cell in the stacked solar cell is equipped with a light absorption layer and a carrier transport layer (e.g., electron transport layer, hole transport layer). The light absorption layer uses a light-absorbing material (e.g., perovskite material) that can absorb photons to generate electron-hole pairs. Under the action of the electric field, the electron-hole pairs are dissociated into carriers (electrons, holes). The directional movement of the dissociated carriers forms an electric current. The presence of the carrier transport layer can enhance the dissociation effect of electrons and holes, thereby effectively improving the photoelectric conversion efficiency of the battery.

[0047] Electrons and holes dissociated from the light-absorbing layer are prone to non-radiative recombination, affecting the photoelectric conversion efficiency of the tandem cell. To further improve the photoelectric conversion efficiency of the tandem cell, it has been proposed to arrange a hole blocking layer between the electron transport layer and the recombination layer of the first cell (the first cell arranged in the incident direction). This can reduce the non-radiative recombination of electrons and holes and improve the photoelectric conversion efficiency.

[0048] To further improve the photoelectric conversion efficiency of tandem cells, especially perovskite tandem cells, it has been found that defects are prone to occur at the grain boundaries of the perovskite light absorbing layer. These defects limit further improvement in the photoelectric conversion efficiency. Therefore, it is proposed to arrange a passivation layer on the surface of the perovskite light absorbing layer. However, the inventors have found that in perovskite tandem cells, even if a hole blocking layer is arranged between the electron transport layer and the recombination layer, and a passivation layer is arranged on the surface of the perovskite light absorbing layer, non-radiative recombination of holes and electrons still occurs. Therefore, there is still room for improvement in the photoelectric conversion efficiency of tandem cells.

[0049] Based on this, the present disclosure provides a stacked solar cell, and a photovoltaic module, a power generation device, and an electric power consumption device including the stacked solar cell.

[0050] Tandem solar cells

[0051] The stacked solar cell provided by the present disclosure includes: a first electrode and a second electrode; at least a first battery unit and a second battery unit arranged in sequence along a first direction between the first electrode and the second electrode; and a composite layer arranged between the first battery unit and the second battery unit, wherein the first direction is the incident direction of light; wherein the first battery unit includes a first light absorption layer, a first electron transport layer, a first hole blocking layer arranged on a side of the first electron transport layer close to the first light absorption layer, and a second hole blocking layer arranged on a side of the first electron transport layer away from the first light absorption layer, and the first light absorption layer contains a perovskite material.

[0052] Various aspects of the disclosed tandem solar cell are further described below with reference to the accompanying drawings.

[0053] Figure 1 is a schematic diagram of a tandem solar cell according to an embodiment of the present disclosure. As shown in Figure 1 , the tandem solar cell 10 includes: a first electrode 11 and a second electrode 12; at least a first cell 13 and a second cell 14 arranged in sequence along a first direction between the first electrode 11 and the second electrode 12; and a recombination layer 15 arranged between the first cell 13 and the second cell 14, wherein the first direction is the incident direction of light. The first cell 13 includes a first hole blocking layer 133 arranged between a first light absorbing layer 132 and a first electron transport layer 134. The first cell 13 further includes a second hole blocking layer 135 arranged on a side of the first electron transport layer 134 away from the first light absorbing layer 132 and in contact with the first electron transport layer 134. The first light absorbing layer 132 comprises a perovskite material.

[0054] In the present disclosure, by arranging the first hole blocking layer 133 and the second hole blocking layer 135, multi-layer blocking of holes in the first battery unit 13 can be achieved, the hole blocking effect can be enhanced, and the non-radiative recombination of holes and electrons can be further reduced, thereby improving the open circuit voltage and photoelectric conversion efficiency of the stacked solar cell.

[0055] Typically, because it is recognized that light-absorbing layers containing perovskite materials are prone to defects at the grain boundaries of the perovskite material, a passivation layer is usually provided between the light-absorbing layer and the electron transport layer. However, in such a structure, non-radiative recombination of holes and electrons still occurs, particularly in the first cell 13 of the tandem cell. In the tandem solar cell proposed in the present disclosure, a first hole blocking layer 133 is used between the first light-absorbing layer 132 and the first electron transport layer 134 instead of the conventional passivation layer, unexpectedly achieving an improvement in photoelectric conversion efficiency.

[0056] The term "tandem solar cell" in this disclosure refers to a solar cell having a structure in which at least two battery cells are sequentially arranged along the incident direction of light. By stacking at least two battery cells, the utilization rate of incident sunlight can be increased.

[0057] The present disclosure has no particular limitation on the number of battery cells included in the stacked solar cell 10. For example, the number of battery cells included in the stacked solar cell can be 2, 3, 4, etc.

[0058] Hereinafter, the description will be made by taking as an example a case where the stacked solar cell 10 includes two battery cells (a first battery cell 13 and a second battery cell 14 ).

[0059] The first electrode 11, which may also be referred to as the bottom electrode, refers to the electrode that first receives incident light and is used to collect electrons / holes. The material used for the first electrode 11 includes a transparent conductive material. The present disclosure does not particularly limit the transparent conductive material included in the first electrode 11. Exemplarily, the transparent conductive material includes: at least one of tin oxide, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), antimony-doped tin oxide, and indium-doped tungsten oxide.

[0060] The second electrode 12, which may also be referred to as the top electrode, refers to the electrode that receives the incident light last and is used to collect electrons / holes. The material used for the second electrode 12 includes a conductive material. The present disclosure does not particularly limit the conductive material included in the second electrode 12. For example, the conductive material includes at least one of an organic conductive material and an inorganic conductive material, wherein the inorganic conductive material includes at least one of the above-mentioned transparent conductive materials, metals and their alloys, and carbon elemental materials. Exemplarily, the metals and their alloys include at least one of gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, and tungsten. Exemplarily, the carbon elemental material includes at least one of graphite, graphene, and carbon nanotubes. Exemplarily, the organic conductive material includes at least one of poly(3,4-ethylenedioxythiophene), polythiophene, and polyacetylene.

[0061] The recombination layer 15 is disposed between the first battery cell 13 and the second battery cell and provides a location for recombination between electrons generated by the first light absorbing layer 132 and holes generated by the second light absorbing layer 142. The present disclosure does not specifically limit the material comprising the recombination layer 15. For example, the recombination layer 15 may include at least one of gold, platinum, indium tin oxide, indium zinc oxide, iron, cobalt, nickel, zinc, manganese, cadmium, silver, and copper. The present disclosure does not specifically limit the thickness of the recombination layer 15; a thickness commonly used in the art can be used.

[0062] In the present disclosure, the first light absorption layer 132 of the first battery cell 13 includes a perovskite material. Through the design of the perovskite material, the first light absorption layer 132 can have a wider band gap (for example, a band gap of 1.6eV-2.3eV), which is beneficial for the first battery cell 13 and the second battery cell 14 with a narrow band gap to form a stacked solar cell 10 with high photoelectric conversion efficiency.

[0063] The present disclosure does not particularly limit the material (second light-absorbing material) used in the second light-absorbing layer arranged in the second battery unit 14, as long as it can absorb photons to generate electron-hole pairs. For example, the second light-absorbing material includes at least one of a crystalline silicon material, a perovskite material, and a heterojunction. In the present disclosure, a tandem solar cell in which the second light-absorbing material includes a perovskite material may also be referred to as a full perovskite tandem cell. A tandem solar cell in which the second light-absorbing material includes a crystalline silicon material may also be referred to as a perovskite-crystalline silicon tandem cell.

[0064] The first battery unit 13 is arranged on the first electrode 11 and includes a first hole transport layer 131 , a first light absorption layer 132 , a first hole blocking layer 133 , a first electron transport layer 134 , and a second hole blocking layer 135 .

[0065] The first hole transport layer 131 includes a hole transport material. The present disclosure places no particular limitation on the hole transport material included in the first hole transport layer 131. For example, the first hole transport layer 131 includes at least one of an inorganic hole transport material and an organic hole transport material. Exemplarily, the inorganic hole transport material includes at least one of metal oxides and cuprous thiocyanate. Exemplarily, the metal oxides include: tin oxide (SnOx, where 1 < x < 2), nickel oxide (NiOx, 1 ≤ x ≤ 2), copper oxide (Cu2O). Exemplarily, the organic hole transport materials include: [2-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid, poly(3,4-ethylenedioxythiophene), poly(styrenesulfonic acid), polystyrene sulfonic acid, poly(3-hexylthiophene), triphenylamine with a triptycene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-anilino)carbazole-spirobifluorene, at least one of polythiophene.

[0066] The present disclosure places no particular limitation on the thickness of the first hole transport layer 131, and the thickness of the hole transport layer commonly used in the art may be adopted.

[0067] The first light absorption layer 132 is disposed on the first hole transport layer 131 and in contact with the first hole transport layer 131, and includes a perovskite material. To improve the photoelectric conversion efficiency, the first light absorption layer 132 including the perovskite material (which may be referred to as the first perovskite material hereinafter) is designed to have a relatively wide bandgap. For example, the bandgap of the first perovskite material is 1.6 eV - 2.3 eV. The first perovskite material is well-known to those skilled in the art. Exemplarily, the first perovskite material is, for example, FA 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3, FA 0.15 Cs 0.85 Pb(I 0.73 Br 0.27 )3, Cs 0.12 MA 0.05 FA 0.83 Pb(I 0.6 Br 0.4 )3.

[0068] The present disclosure places no particular limitation on the thickness of the first light absorption layer 132, and the thickness of the light absorption layer commonly used in the art may be adopted.

[0069] The first electron transport layer 134 is disposed on a side of the first light absorption layer 132 away from the first hole transport layer 131 and includes an electron transport material. The present disclosure places no particular limitation on the electron transport material included in the first electron transport layer 134. Exemplarily, the electron transport material includes: fullerenes and their derivatives (for example, C 60), metal oxides (such as oxides containing at least one of magnesium, cadmium, zinc, indium, lead, tungsten, bismuth, mercury, titanium, silver, manganese, iron, and vanadium), silicon oxide, strontium titanate, calcium titanate, lithium fluoride, and at least one of calcium fluoride.

[0070] The present disclosure has no particular limitation on the thickness of the first electron transport layer 134 , and the thickness of the electron transport layer conventionally used in the art may be adopted.

[0071] The first hole blocking layer 133 is disposed between the first light absorbing layer 132 and the first electron transporting layer 134 , and is used to block the holes dissociated from the first light absorbing layer 132 from being transported toward the first electron transporting layer 134 .

[0072] The first hole blocking layer 133 includes a first hole blocking material. The first hole blocking material may be a conventional hole blocking material, but the difference (σ) between the HOMO energy level of the first hole blocking material and the HOMO energy level of the first perovskite material must be less than 0.

[0073] In some embodiments, the first hole blocking material is selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), SnO2, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI), 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene (B3PyPB), diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide (TSPO1), 2,7-bis(2,2'-bipyridin-5-yl)triphenylene (BPy-TP2), bis(1,3- ... At least one of (8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum, (6-(1,10-phenanthroline-3-yl)naphthalene-2-yl)diphenylphosphine oxide (Phen-NaDPO), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, and benzophenanthroline.

[0074] The present disclosure discovered that these materials can be used in perovskite solar cells and can effectively increase the open circuit voltage. It is speculated that they have both the function of hole blocking and the role of passivating the perovskite light absorption layer.

[0075] Therefore, in some embodiments, the first hole blocking material is selected from at least one of BCP, TPBI, B3PyPB, TSPO1, BPy-TP2, bis(8-hydroxy-2-methylquinolinol)-(4-phenylphenoxy)aluminum, Phen-NaDPO, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, and benzophenanthroline. These materials can not only block the migration of holes, but also passivate the A site of the perovskite material, thereby having the dual functions of reducing defects at the grain boundaries of the perovskite material in the first light absorbing layer 132 and blocking non-radiative recombination of holes and electrons.

[0076] The applicant has found that the blocking effect of the first hole blocking layer 133 on holes is related to σ. The larger the absolute value of σ is, the stronger the blocking effect of the first hole blocking layer 133 on holes is.

[0077] In some embodiments, the difference σ between the HOMO energy level of the first hole-blocking material and the HOMO energy level of the perovskite material in the first light-absorbing layer is less than or equal to -0.1 eV. For example, σ is -0.1 eV, -0.11 eV, -0.12 eV, -0.13 eV, -0.14 eV, -0.15 eV, or a range between any two values, but is not limited thereto. When σ is within the above range, the hole-blocking effect of the first hole-blocking layer 133 can be further enhanced.

[0078] In some embodiments, the thickness (d1) of the first hole blocking layer 133 is 5 nm to 20 nm, and optionally, d1 is 5 nm to 16 nm. For example, the thickness of the first hole blocking layer is 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, or a range between any two values, but is not limited thereto. By controlling the thickness of the first hole blocking layer 133 within the above range, the first hole blocking layer 133 is conducive to exerting its hole-blocking advantage while also helping to reduce the absorption of sunlight by the first hole blocking layer 133.

[0079] The second hole blocking layer 135 is disposed on the first electron transport layer 134. The second hole blocking layer 135 includes a second hole blocking material. The present disclosure has no particular limitation on the second hole blocking material. For example, the second hole blocking material may include at least one of fullerene and its derivatives, BCP, and SnO2. For example, fullerene and its derivatives include PCBM, C 60 At least one of .

[0080] In some embodiments, the second battery cell includes a second light absorbing layer, a second electron transport layer, and a third hole blocking layer disposed between the second light absorbing layer and the second electron transport layer. The third hole blocking layer blocks holes, further reducing non-radiative recombination of electrons and holes.

[0081] Referring to the stacked solar cell (all perovskite stacked cell) 100 shown in Figure 2, in this embodiment, the first battery unit 13 is arranged on the first electrode 11, and includes a first hole transport layer 131, a first light absorption layer 132, a first hole blocking layer 133, a first electron transport layer 134, and a second hole blocking layer 135 arranged in sequence along the first direction; the second battery unit 14 is arranged on the composite layer 15, and includes a second hole transport layer 141, a second light absorption layer 142, a third hole blocking layer 143, and a second electron transport layer 144 arranged in sequence along the first direction; the second electrode 12 is arranged on the side of the second electron transport layer 144 away from the third hole blocking layer 143; wherein the second light absorption layer 142 contains a perovskite material.

[0082] In this embodiment, the first battery unit 13 , the first electrode 11 , the second electrode 12 and the composite layer 15 are the same as those in the above embodiment and are not described again herein.

[0083] The second hole transport layer 141 includes a hole transport material. The present disclosure does not particularly limit the hole transport material included in the second hole transport layer 141. Specific examples of the hole transport material included in the second hole transport layer 141 are the same as the hole transport material in the first hole transport layer in the above embodiment and are not further described here.

[0084] The present disclosure has no particular limitation on the thickness of the second hole transport layer 141 , and the thickness of the hole transport layer conventionally used in the art may be adopted.

[0085] The second light absorbing layer 142 includes a light absorbing material (hereinafter referred to as the second light absorbing material).

[0086] In this embodiment, the second light absorbing material comprises a perovskite material. The perovskite material has a high photoelectric conversion efficiency. The use of a second light absorbing layer comprising a perovskite material is beneficial to further improve the photoelectric conversion efficiency of the stacked cell. In some embodiments, the band gap of the perovskite material in the first light absorbing layer 132 is wider than the band gap of the perovskite material in the second light absorbing layer 142. For example, the band gap of the perovskite material included in the first light absorbing layer 132 is 1.6eV-2.3eV, and the band gap of the perovskite material included in the second light absorbing layer 142 is 1.1eV-1.4eV. Exemplarily, the perovskite material included in the second light absorbing layer 142 is, for example, MA 0.3 FA 0.7Pb 0.5 Sn 0.5 I3、MAPb 0.85 Sn 0.15 I3、FAPb 0.5 Sn 0.5 I3、FA 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3.

[0087] The present disclosure has no particular limitation on the thickness of the second light absorbing layer 142 , and the thickness of the light absorbing layer conventionally used in the art may be adopted.

[0088] The second electron transport layer 144 includes an electron transport material. The present disclosure does not particularly limit the electron transport material included in the second electron transport layer 144. Specific examples of the electron transport material included in the second electron transport layer 144 are the same as those in the above embodiment and are not repeated here.

[0089] The present disclosure has no particular limitation on the thickness of the second electron transport layer 144 , and the thickness of the electron transport layer conventionally used in the art may be adopted.

[0090] The third hole blocking layer 143 is arranged between the second light absorbing layer 142 and the second electron transporting layer 144, and is used to block the holes dissociated from the second light absorbing layer 142 from being transmitted to the second electron transporting layer 144. The third hole blocking layer 143 includes a third hole blocking material. The third hole blocking material can be a conventional hole blocking material, but the difference (ω) between the HOMO energy level of the third hole blocking material and the HOMO energy level of the second light absorbing material is less than 0. In some embodiments, the third hole blocking material can be the same as the first hole blocking material.

[0091] In some embodiments, the third hole blocking material is selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), SnO2, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI), 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene (B3PyPB), diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide (TSPO1), 2,7-bis(2,2'-bipyridin-5-yl)triphenylene (BPy-TP2), bis(8-hydroxy-2-methylquinoline)- (4-Phenylphenoxy)aluminum, (6-(1,10-phenanthroline-3-yl)naphthalene-2-yl)diphenylphosphine oxide (Phen-NaDPO), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, benzophenanthroline, copper phthalocyanine (CuPc), 8-hydroxyquinoline-lithium (Liq), BN-ICz-1(C 50 H 40 BN3), 2,7-bis[N-(m-tolyl)phenylamino]-9,9'-spirobi[9H-fluorene](C 51 H 38 N2) at least one.

[0092] Among them, the chemical formula of BN-ICz-1 is

[0093] In some embodiments, the third hole blocking material is selected from at least one of BCP, TPBI, B3PyPB, TSPO1, BPy-TP2, bis(8-hydroxy-2-methylquinolinol)-(4-phenylphenoxy)aluminum, Phen-NaDPO, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, benzophenanthroline, CuPc, 8-hydroxyquinolinol-lithium, and BN-ICz-1. Similarly, the above materials can not only block the migration of holes, but also passivate the A site of the perovskite material, thereby having the dual functions of reducing defects at the grain boundaries of the perovskite material of the second light absorbing layer 142 and blocking non-radiative recombination of electrons and holes.

[0094] The applicant has found that the blocking effect of the third hole blocking layer 143 on holes is related to ω. The larger the absolute value of ω is, the stronger the blocking effect of the third hole blocking layer 143 on holes is.

[0095] In some embodiments, the difference ω between the HOMO energy level of the third hole-blocking material and the HOMO energy level of the second light-absorbing material is less than or equal to -0.1 eV. For example, ω is -0.11 eV, -0.12 eV, -0.13 eV, -0.14 eV, -0.15 eV, or a range between any two values, but is not limited thereto. When ω is within the above range, the third hole-blocking layer 143 further enhances its hole-blocking effect.

[0096] In some embodiments, d3 is 5 nm to 20 nm, optionally 5 nm to 10 nm, 6 nm to 10 nm, 6 nm to 8 nm, etc. For example, d3 is 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, or a range between any two values, but is not limited thereto. By controlling the thickness of the third hole blocking layer 143 within the above range, while leveraging its hole blocking advantage, it is also beneficial to reduce the absorption of sunlight by the third hole blocking layer 143. This is beneficial for stacked solar cells with more battery cells.

[0097] Referring to the stacked solar cell (all perovskite stacked cell) 200 shown in Figure 3, in this embodiment, the first battery unit 13 is arranged on the first electrode 11, and includes a first hole transport layer 131, a first light absorption layer 132, a first hole blocking layer 133, a first electron transport layer 134, and a second hole blocking layer 135 arranged in sequence along the first direction; the second battery unit 14 is arranged on the composite layer 15, and includes a second hole transport layer 141, a second light absorption layer 142, a third hole blocking layer 143, and a second electron transport layer arranged in sequence along the first direction, wherein the second battery unit 14 further includes a fourth hole blocking layer 145 arranged on a side of the second electron transport layer 144 away from the third hole blocking layer 143 and in contact with the second electron transport layer 144, and the second electrode 12 is arranged on a side of the fourth hole blocking layer 145 away from the second electron transport layer 144, wherein the second light absorption layer 142 contains a perovskite material. The structure of the tandem solar cell 200 of this embodiment differs from that of the tandem solar cell 100 of the aforementioned embodiment in that it includes a fourth hole blocking layer 145. The arrangement of the first hole blocking layer 133, the second hole blocking layer 135, the third hole blocking layer 143, and the fourth hole blocking layer 145 achieves multi-layer hole blocking, enhancing the hole blocking effect and further improving the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell 200.

[0098] The fourth hole blocking layer 145 includes a fourth hole blocking material. The present disclosure has no particular limitation on the fourth hole blocking material. For example, the fourth hole blocking material may include at least one of fullerene and its derivatives, SnO2, and bathocuproine (BCP). For example, fullerene and its derivatives such as PCBM, C 60 The fourth hole blocking material may be the same as or different from the second hole blocking material.

[0099] The other layers are the same as those in the above embodiment and will not be described again here.

[0100] See the tandem solar cell (perovskite-crystalline silicon tandem cell) 300 shown in Figure 4. In this embodiment, the first battery unit 13 is arranged on the first electrode 11 and includes a second hole blocking layer 135, a first electron transport layer 134, a first hole blocking layer 133, a first light absorbing layer 132, and a first hole transport layer 131 arranged in sequence along the first direction. The second battery unit 14 is arranged on the recombination layer 15 and includes a second electron transport layer 144, a third hole blocking layer 143, a second light absorbing layer 142, and a second hole transport layer 141 arranged in sequence along the first direction. The second electrode 12 is arranged on the side of the second hole transport layer 141 away from the second light absorbing layer 142. The second light absorbing layer 142 arranged in the second battery unit comprises a crystalline silicon material. Exemplarily, the crystalline silicon material comprises single crystal silicon.

[0101] The remaining layers are the same as those in the previous embodiment and will not be described again here.

[0102] In the tandem solar cell disclosed herein, the first cell unit is a perovskite cell unit, with a perovskite material as the first light absorption layer. The second cell unit can be a perovskite cell unit or other cell units, wherein the second light absorption layer can be made of a perovskite material, a crystalline silicon material, or a heterojunction material, etc. A detailed list of these is omitted here.

[0103] The present disclosure does not particularly limit the preparation method of each functional layer of the stacked solar cell, and may include conventional preparation methods in the art, such as evaporation, atomic layer deposition, spin coating, etc.

[0104] The embodiments of the present disclosure further provide a photovoltaic module. Typically, the photovoltaic module includes the aforementioned stacked solar cells, a welding ribbon connecting multiple stacked solar cells, a junction box for current transmission, and a battery packaging component.

[0105] In some embodiments, the battery packaging component includes photovoltaic glass, which covers the laminated solar cells and protects them. Photovoltaic glass also has excellent light transmittance and high hardness, making it adaptable to large temperature swings between day and night and adverse weather conditions.

[0106] In some embodiments, the cell encapsulation component includes an ethylene-vinyl acetate copolymer (EVA) film, which is disposed between the photovoltaic glass and the laminated solar cell to bond the photovoltaic glass and the solar cell.

[0107] In some embodiments, the cell packaging component includes a photovoltaic backsheet, which also serves to protect the laminated solar cells.

[0108] Optionally, the material of the photovoltaic backsheet can be a polyvinyl fluoride composite film or a thermoplastic elastic material. The material of the photovoltaic backsheet has the properties of insulation, waterproofness, and aging resistance.

[0109] In some embodiments, the battery packaging component includes a solar aluminum frame, which is made of aluminum alloy and has the characteristics of high strength and good corrosion resistance, and can support and protect the solar cell.

[0110] The embodiments of the present disclosure also provide a power generation device, comprising the stacked solar cell provided in the above embodiments.

[0111] The embodiments of the present disclosure further provide an electrical device, comprising the stacked solar cell provided in the above embodiments.

[0112] In some embodiments, the electrical device may also be a lighting device, an energy storage device, etc., and the embodiments of the present disclosure include but are not limited to the above. For example, the electrical device may be a solar water heater, a solar street light, a solar photovoltaic generator, etc.

[0113] Example

[0114] The following examples are provided. The examples described below are illustrative and are intended only to explain the present disclosure and are not to be construed as limiting the present disclosure. Unless otherwise specified, all reagents used were commercially available and all equipment used was conventional.

[0115] The applicant tested the PLQY and open-circuit voltage loss of perovskite devices with a passivation layer and a hole blocking layer, and found that even if a hole blocking layer is arranged between the electron transport layer and the recombination layer, and a passivation layer is arranged on the surface of the perovskite light absorption layer, non-radiative recombination of holes and electrons still occurs.

[0116] Preparation of samples to be tested:

[0117] Sample 1 (hole transport layer / perovskite light absorption layer)

[0118] (1) Providing a hole transport layer: On the FTO conductive glass treated with UV ozone, a 15 mg / mL NiOx (1≤x≤2) nanoparticle aqueous solution was spin-coated at a rate of 2000 rpm / s in a glove box to form a hole transport layer with a thickness of 30 nm, and then thermally annealed at 150°C for 10 min.

[0119] (2) Providing a perovskite light absorption layer: Weigh 1659 mg of lead iodide, 880 mg of lead bromide, 240 mg of bromoformamidine, 495 mg of iodoformamidine, 187 mg of cesium iodide, and 102 mg of cesium bromide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 4:1). Stir for 1 hour and filter with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution. Take 100 μL of the perovskite precursor solution and spin-coat the perovskite precursor solution on the hole transport layer at 5000 rpm, then place it in a vacuum flash evaporation device for 30 seconds, transfer it to a 100°C hot stage for annealing for 10 minutes, and form a perovskite light absorption layer (FA) with a thickness of 500 nm. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3).

[0120] Sample 2 (hole transport layer / perovskite light absorption layer / passivation layer / electron transport layer / hole blocking layer)

[0121] (1) Providing a hole transport layer: On the FTO conductive glass treated with UV ozone, a 15 mg / mL NiOx (1≤x≤2) nanoparticle aqueous solution was spin-coated at a rate of 2000 rpm / s in a glove box to form a hole transport layer with a thickness of 30 nm, and then thermally annealed at 150°C for 10 min.

[0122] (2) Providing a perovskite light absorption layer: Weigh 1659 mg of lead iodide, 880 mg of lead bromide, 240 mg of bromoformamidine, 495 mg of iodoformamidine, 187 mg of cesium iodide, and 102 mg of cesium bromide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 4:1). Stir for 1 hour and filter with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution. Take 100 μL of the perovskite precursor solution and spin-coat the perovskite precursor solution on the hole transport layer at 5000 rpm, then place it in a vacuum flash evaporation device for 30 seconds, transfer it to a 100°C hot stage for annealing for 10 minutes, and form a perovskite light absorption layer (FA) with a thickness of 500 nm. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3).

[0123] (3) Providing a passivation layer: Take 100 μl of an isopropanol solution of phenylethylamine iodine (5 mg / mL) and spin-coat it on the perovskite light absorption layer at a spin-coating speed of 4000 rpm and an acceleration of 1000 rpm / s for 25 s. Anneal for 5 min to form a 10 nm thick passivation layer.

[0124] (4) Providing an electron transport layer: Evaporating a C layer with a thickness of 20 nm on the above passivation layer 60 as an electron transport layer.

[0125] (5) Providing a hole blocking layer: A 20 nm thick SnO2 layer was deposited on the electron transport layer by atomic layer deposition as a hole blocking layer.

[0126] Test the external quantum efficiency (PLQY) and open circuit voltage loss of the above samples

[0127] (1) PLQY of the test samples (sample 1 and sample 2) A photoluminescence fluorescence spectrometer (PLS980, Edinburgh Instruments) was used to test the PLQY of sample 1 and sample 2 respectively. During the test, the sample was irradiated with reflected light from the excitation light source, and electrons jumped from the valence band to the conduction band and left holes in the valence band; the electrons and holes relaxed in their respective conduction bands and valence bands to reach their respective lowest unoccupied excited states, becoming a quasi-equilibrium state; the electrons and holes in the quasi-equilibrium state then recombine to emit light, forming a spectrum of the intensity or energy distribution of light of different wavelengths. The PLQY of the sample was obtained based on the spectrum. The test results are shown in Table 1.

[0128] (2) Calculate the open circuit voltage loss of the sample

[0129] The open circuit voltage loss (ΔVoc nrad) caused by non-radiative recombination was calculated based on formula (I), and the calculation results are shown in Table 1.

[0130] Here, k is the Boltzmann constant, T is the temperature, q is the elementary charge, and PLQY is the external quantum efficiency.

[0131] Table 1

[0132] In Table 1, ΔVoc nrad1 represents the open circuit voltage loss caused by the non-radiative recombination of electrons and holes at the interface between the hole transport layer and the perovskite light absorbing layer and in the bulk of the perovskite light absorbing layer.

[0133] ΔVoc nrad2 represents the open circuit voltage loss caused by the non-radiative recombination of electrons and holes at the interface between the hole transport layer and the perovskite light absorption layer, the bulk of the perovskite light absorption layer, the interface between the perovskite light absorption layer and the passivation layer, and the interface between the passivation layer and the electron transport layer.

[0134] The above results show that compared with the structure with only a hole transport layer and a perovskite light absorption layer, even if a hole blocking layer is arranged on the side of the electron transport layer away from the perovskite light absorption layer, and a passivation layer is arranged on the surface of the perovskite light absorption layer, non-radiative recombination of holes and electrons may still occur, resulting in an open-circuit voltage loss of about 80mV (ΔVoc nrad2-ΔΔVoc nrad1).

[0135] In the present disclosure, the conventional passivation layer is replaced with the first hole blocking layer, thereby improving the open circuit voltage and the photoelectric conversion effect. The present disclosure is further illustrated by the following examples.

[0136] Example 1

[0137] Preparation of tandem solar cells (all perovskite tandem cells):

[0138] (1) Providing a first electrode: Take a 2.0*2.0 cm FTO conductive glass, remove 0.35 cm of FTO at each end by laser etching, and expose the glass substrate; ultrasonically clean the etched FTO conductive glass with cleaning solution, deionized water, and ethanol in sequence; blow the solvent out of the FTO conductive glass under a nitrogen gun, and place it in a UV ozone machine for further cleaning.

[0139] (2) Providing a first hole transport layer: On the FTO conductive glass treated with UV ozone, a 15 mg / mL NiOx (1≤x≤2) nanoparticle aqueous solution was spin-coated at a rate of 2000 rpm / s in a glove box to form a first hole transport layer with a thickness of 30 nm, and then thermally annealed at 150°C for 10 min.

[0140] (3) Providing a first light absorption layer: Weigh 1659 mg of lead iodide, 880 mg of lead bromide, 240 mg of bromoformamidine, 495 mg of iodoformamidine, 187 mg of cesium iodide, and 102 mg of cesium bromide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 4:1). Stir for 1 hour, filter with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution, take 100 μL of the perovskite precursor solution, spin-coat the perovskite precursor solution on the first hole transport layer at 5000 rpm, then place it in a vacuum flash evaporation device for 30 seconds, transfer it to a hot plate at 100°C for annealing for 10 minutes, and form a first light absorption layer (FA) with a thickness of 500 nm. 0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3).

[0141] (4) Providing a first hole blocking layer: Bathocuproin (a first hole blocking material, BCP) is evaporated on the first light absorbing layer to a thickness (d1) of 10 nm as the first hole blocking layer.

[0142] (5) Providing a first electron transport layer: Vapor-depositing a C layer with a thickness of 20 nm on the first hole blocking layer 60 As the first electron transport layer.

[0143] (6) Providing a second hole blocking layer: SnO2 (a second hole blocking material) is deposited on the first electron transport layer by atomic layer deposition to a thickness of 20 nm as the second hole blocking layer.

[0144] (7) Providing a composite layer: Au with a thickness of 1 nm is evaporated on the second hole blocking layer as a composite layer.

[0145] (8) Providing a second hole transport layer: Spin-coat a mixed solution of poly (3,4-ethylenedioxythiophene) and polystyrene sulfone on the composite layer at a spin coating speed of 3000 rpm for 20 s, and then transfer to a hot plate and anneal at 150° C. for 15 min to form a second hole transport layer with a thickness of 15 nm.

[0146] (9) Providing a second light absorbing layer: adding 2 mg of iodomethane, 85 mg of iodomethylamine, 4 mg of lead iodide, and 335 mg of stannous iodide to 1 mL of a mixed solvent of DMF and DMSO (the volume ratio of DMF to DMSO is 2:1), stirring at a speed of 600 rpm on a magnetic stirrer for 2 h, filtering to obtain a perovskite precursor solution; spin-coating 100 μL of the above perovskite precursor solution onto the above second hole transport layer, first at a spin-coating speed of 1 000 rpm, acceleration 200 rpm / s spin coating for 10s, then spin coating at a spin coating speed of 3000 rpm, acceleration 1000 rpm / s for 20s, then add 500 μL of ethyl acetate to the spin-coated perovskite precursor solution, then spin-coat the above perovskite precursor solution again, the spin coating speed is 4000 rpm, the spin coating time is 20s, and then transfer to a hot stage for annealing at 100 ° C for 10 minutes to form a second light absorption layer (FA) with a thickness of 1 μm 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3).

[0147] (10) Providing a third hole blocking layer: spin-coating a 0.5 mg / mL BCP chlorobenzene solution (third hole blocking material) on the second light absorbing layer, and then transferring it to a hot plate and annealing it at 100° C. for 5 min to form a third hole blocking layer with a thickness (d3) of 7 nm.

[0148] (11) Providing a second electron transport layer: spin-coating a 15 mg / mL fullerene derivative (PCBM) chlorobenzene solution on the third hole blocking layer to form a second electron transport layer with a thickness of 10 nm.

[0149] (12) Providing a fourth hole blocking layer: On the second electron transport layer, bathocuproin (a fourth hole blocking material) was evaporated to a thickness of 10 nm as the fourth hole blocking layer.

[0150] (13) Providing a second electrode: On the fourth hole blocking layer, metal copper is evaporated to a thickness of 100 nm as the second electrode.

[0151] Testing of material HOMO energy levels

[0152] A graph is drawn based on the test data of valence band X-ray photoelectron spectroscopy (VB XPS), and the straight line portion of the obtained graph near 0 eV is extrapolated to intersect with the horizontal extension line. The intersection point is the HOMO energy level of the material.

[0153] Open circuit voltage (Voc) and photoelectric conversion efficiency (PCE) testing of tandem solar cells

[0154] Under atmospheric conditions, an AM1.5G standard light source was used as a sunlight simulating light source, and a four-channel digital source meter (Keithley 2440) was used to measure the volt-ampere characteristic curve of the battery under illumination. Based on the volt-ampere characteristic curve, the open-circuit voltage, short-circuit current density (Jsc), and passivation factor (FF) of the stacked solar cell were obtained.

[0155] The photoelectric conversion efficiency (PCE) of the tandem solar cell is calculated using the following formula;

[0156] PCE=Pout / Popt=Voc×Jsc×(Vmpp×Jmpp) / (Voc×Jsc)=Voc×Jsc×FF / Popt.

[0157] Pout, Popt, Vmpp, and Jmpp are the battery operating output power, incident light power, battery maximum power point voltage, and maximum power point current, respectively.

[0158] Example 2

[0159] A stacked solar cell was prepared according to the method of Example 1, except that the fourth hole blocking layer was not formed.

[0160] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 2.

[0161] Example 3

[0162] A stacked solar cell was prepared according to the method of Example 1, except that the third hole blocking layer and the fourth hole blocking layer were not formed.

[0163] Example 4

[0164] A stacked solar cell was prepared according to the method of Example 1, except that SnO2 was used as the hole blocking material in the first hole blocking layer.

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

[0166] Comparative Example 1

[0167] A stacked solar cell was prepared according to the method of Example 1, except that the first hole blocking layer, the third hole blocking layer and the fourth hole blocking layer were not formed.

[0168] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 2.

[0169] Comparative Example 2

[0170] A stacked solar cell was prepared according to the method of Example 1, except that the first hole blocking layer and the fourth hole blocking layer were not formed.

[0171] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 2.

[0172] Comparative Example 3

[0173] A stacked solar cell was prepared according to the method of Example 1, except that the first hole blocking layer and the third hole blocking layer were not formed.

[0174] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 2.

[0175] Comparative Example 4

[0176] A stacked solar cell was prepared according to the method of Example 1, except that the first hole blocking layer, the third hole blocking layer, and the fourth hole blocking layer were not formed. A passivation layer was formed between the first light absorbing layer and the first electron transport layer. The passivation layer was prepared by taking 100 μl of an isopropanol solution of phenylethylamine iodide (5 mg / mL), spin coating at a spin coating speed of 4000 rpm and an acceleration of 1000 rpm / s for 25 seconds, and annealing for 5 minutes to form a 10 nm thick passivation layer.

[0177] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 2.

[0178] Table 2

[0179] The data in Table 2 show that the calcium tandem solar cells prepared in Examples 1 to 4 have a first hole blocking layer disposed between the first light absorbing layer and the first electron transport layer. Compared to the calcium tandem solar cells prepared in Comparative Examples 1 to 4, the calcium tandem solar cells prepared in Examples 1 to 4 have improved open circuit voltage and photoelectric conversion efficiency.

[0180] Example 5

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

[0182] (1) Providing crystalline silicon cells: A textured n-type single crystal silicon wafer (c-Si) is cleaned with hydrogen peroxide solution, hydrofluoric acid, and hydrochloric acid in sequence as the second light absorption layer. On one side, intrinsic amorphous silicon (ia-Si:H) is deposited by PECVD to passivate the c-Si surface. A p-doped a-Si:H layer (the second hole transport layer) of approximately 10 nm is then deposited by PECVD on the ia-Si:H surface. Then, a 1.5 nm thick SiO2 layer is grown on the other side by wet chemical methods (oxidation reaction in 68% mass fraction concentrated nitric acid at 90°C for 30 minutes) as the third hole blocking layer. Then, an n-doped a-Si:H layer (the second electron transport layer) of approximately 5 nm thick is deposited by PECVD on its surface. A 20 nm thick ITO layer is deposited on the n-type layer side as a composite layer, and an 80 nm thick ITO layer is deposited on the p-type layer side by magnetron sputtering (PVD) as a transparent electrode (the second electrode). Then, an Ag gate is screen-printed on the p-type side as a back electrode.

[0183] (2) Providing a first hole transport layer: On the n-type side of the ITO (composite layer), a 15 mg / mL NiOx nanoparticle solution was spin-coated at a rate of 2000 rpm / s in a glove box to form a first hole transport layer with a thickness of 30 nm, followed by thermal annealing at 150°C for 10 min.

[0184] (3) Providing a first light absorption layer: Weigh 1659 mg of lead iodide, 880 mg of lead bromide, 240 mg of bromoformamidine, 495 mg of iodoformamidine, 187 mg of cesium iodide, and 102 mg of cesium bromide and dissolve them in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 4:1). Stir for 1 hour, filter with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution, take 100 μL of the perovskite precursor solution, spin-coat the perovskite precursor solution on the first hole transport layer at 5000 rpm, then place it in a vacuum flash evaporation device for 30 seconds, transfer it to a hot plate at 100°C for annealing for 10 minutes, and form a first light absorption layer (FA) with a thickness of 500 nm.0.8 Cs 0.2 Pb(I 0.6 Br 0.4 )3).

[0185] (4) Providing a first hole blocking layer: Bathocuproin (a first hole blocking material, BCP) is evaporated on the first light absorbing layer to a thickness (d1) of 10 nm as the first hole blocking layer.

[0186] (5) Providing a first electron transport layer: C60 with a thickness of 20 nm was evaporated on the above-mentioned first hole blocking layer as the first electron transport layer.

[0187] (6) Providing a second hole blocking layer: SnO2 (a second hole blocking material) is deposited on the first electron transport layer by atomic layer deposition to a thickness of 20 nm as the second hole blocking layer.

[0188] (7) Providing a first electrode: A 100 nm thick metal ITO was deposited on the second hole blocking layer by PVD as the first electrode. Performance tests were conducted in the same manner as in Example 1. The test results are shown in Table 3.

[0189] Comparative Example 5

[0190] A stacked solar cell was prepared according to the method of Example 5, except that the first hole blocking layer was not formed.

[0191] The performance test was carried out in the same manner as in Example 5. The test results are shown in Table 3.

[0192] Table 3

[0193] The data in Table 3 show that the perovskite-crystalline silicon tandem cell prepared in Example 5 includes a first hole-blocking layer disposed between the first light-absorbing layer and the first electron-transporting layer. Compared to the perovskite-crystalline silicon tandem cell prepared in Comparative Example 5, the perovskite-crystalline silicon tandem cell prepared in Example 5 exhibits improved open-circuit voltage and photoelectric conversion efficiency.

[0194] Examples 6-9

[0195] The stacked solar cells of Examples 6-9 were prepared according to the method of Example 1, except that the first hole blocking material or the third hole blocking material was adjusted as shown in Table 4-1.

[0196] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 4-2.

[0197] Table 4-1

[0198] Table 4-2

[0199] Tables 4-1 and 4-2 show that when the difference between the HOMO energy level of the first hole-blocking material and the HOMO energy level of the perovskite material in the first light-absorbing layer is less than or equal to -0.1 eV, the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell can be further improved. Similarly, when the difference between the HOMO energy level of the third hole-blocking material and the HOMO energy level of the second light-absorbing material is less than -0.1 eV, the open-circuit voltage and photoelectric conversion efficiency of the tandem solar cell can be further improved.

[0200] Examples 10 to 13

[0201] A stacked solar cell was prepared according to the method of Example 1, except that d1 or d3 was adjusted as shown in Table 5.

[0202] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 5.

[0203] Table 5

[0204] The data in Table 5 show that a first hole blocking layer thickness of 5 nm to 16 nm is beneficial for further improving the open-circuit voltage and photoelectric conversion efficiency of the calcium tandem solar cell. Compared with the data in Example 13, a third hole blocking layer thickness of 7 nm can further improve the open-circuit voltage and photoelectric conversion efficiency of the calcium tandem solar cell.

[0205] Example 14

[0206] A stacked solar cell was prepared according to the method of Example 1, except that the step of providing a first hole blocking layer included spin coating a 0.5 mg / mL bathocuproin chlorobenzene solution on the first light absorbing layer, followed by transferring the layer to a hot plate and annealing at 100° C. for 5 minutes to form a first hole blocking layer with a thickness of 10 nm.

[0207] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 6.

[0208] Example 15

[0209] A stacked solar cell was prepared according to the method of Example 1, except that the step of providing the third hole blocking layer included: evaporating 7 nm of bathocuproin as the third hole blocking layer.

[0210] The performance test was carried out in the same manner as in Example 1. The test results are shown in Table 6.

[0211] Table 6

[0212] It can be seen from the data in Table 6 that compared with Comparative Examples 1-4, the open circuit voltage and photoelectric conversion efficiency of the calcium stack solar cells obtained by forming the hole blocking layer (first hole blocking layer, third hole blocking layer) by gas phase or solution method are improved.

[0213] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present disclosure are included within the technical scope of the present disclosure. In addition, without departing from the scope of the present disclosure, any other embodiments that can be conceived by those skilled in the art by applying various modifications to the embodiments or combining some of the constituent elements of the embodiments are also included within the scope of the present disclosure.

Claims

1. A tandem solar cell, comprising: a first electrode and a second electrode; at least a first battery cell and a second battery cell arranged in sequence along a first direction between the first electrode and the second electrode; and a composite layer disposed between the first battery cell and the second battery cell, wherein the first direction is an incident direction of light; The first battery unit includes a stacked first light absorbing layer, a first electron transport layer, a first hole blocking layer arranged on a side of the first electron transport layer close to the first light absorbing layer, and a second hole blocking layer arranged on a side of the first electron transport layer away from the first light absorbing layer, wherein the first light absorbing layer contains a perovskite material.

2. The tandem solar cell according to claim 1, wherein: The second battery cell includes a second light absorbing layer, a second electron transporting layer, and a third hole blocking layer disposed between the second light absorbing layer and the second electron transporting layer.

3. The tandem solar cell according to claim 1 or 2, wherein: The first hole blocking layer includes a first hole blocking material, and a difference between a HOMO energy level of the first hole blocking material and a HOMO energy level of a perovskite material in the first light absorbing layer is less than or equal to -0.1 eV.

4. The tandem solar cell according to claim 2, wherein: The third hole blocking layer includes a third hole blocking material, the second light absorbing layer includes a second light absorbing material, and a difference between the HOMO energy levels of the third hole blocking material and the second light absorbing material is less than -0.1 eV.

5. The tandem solar cell according to any one of claims 1 to 4, wherein The thickness of the first hole blocking layer is 5 nm to 20 nm.

6. The tandem solar cell according to claim 5, wherein: The thickness of the first hole blocking layer is 5 nm to 16 nm.

7. The tandem solar cell according to claim 2 or 4, wherein: The thickness of the third hole blocking layer is 5 nm to 20 nm.

8. The tandem solar cell according to claim 7, wherein: The thickness of the third hole blocking layer is 5 nm to 10 nm.

9. The tandem solar cell according to claim 2 or 4, wherein: The first battery unit is arranged on the first electrode and includes a first hole transport layer, a first light absorption layer, a first hole blocking layer, a first electron transport layer, and a second hole blocking layer arranged in sequence along a first direction; The second battery unit is arranged on the composite layer and includes a second hole transport layer, a second light absorbing layer, a third hole blocking layer, and a second electron transport layer arranged in sequence along the first direction; the second electrode is arranged on a side of the second electron transport layer away from the third hole blocking layer; Wherein, the second light absorbing layer comprises perovskite material.

10. The tandem solar cell according to claim 2 or 4, wherein: The first battery unit is arranged on the first electrode and includes a first hole transport layer, a first light absorption layer, a first hole blocking layer, a first electron transport layer, and a second hole blocking layer arranged in sequence along a first direction; The second battery unit is arranged on the composite layer and includes a second hole transport layer, the second light absorbing layer, the third hole blocking layer, and the second electron transport layer arranged in sequence along the first direction, wherein the second battery unit further includes a fourth hole blocking layer arranged on a side of the second electron transport layer away from the third hole blocking layer and in contact with the second electron transport layer, and the second electrode is arranged on a side of the fourth hole blocking layer away from the second electron transport layer; Wherein, the second light absorbing layer comprises perovskite material.

11. The tandem solar cell according to claim 2 or 4, wherein: The first battery unit is arranged on the first electrode and includes the second hole blocking layer, the first electron transport layer, the first hole blocking layer, the first light absorbing layer, and the first hole transport layer arranged in sequence along a first direction; The second battery unit is arranged on the composite layer and includes the second electron transport layer, the third hole blocking layer, the second light absorbing layer, and the second hole transport layer arranged in sequence along the first direction, and the second electrode is arranged on a side of the second hole transport layer away from the second light absorbing layer; Wherein, the second light absorbing layer comprises crystalline silicon material.

12. The tandem solar cell according to any one of claims 1 to 10, wherein: The first hole blocking layer includes 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, SnO2, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide, 2,7-bis(2,2'-bipyridin-5-yl)triphenylene, bis(8-hydroxy-2-methylquinoline)-(4 -phenylphenoxy)aluminum, (6-(1,10-phenanthroline-3-yl)naphthalene-2-yl)diphenylphosphine oxide, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, and at least one of benzophenanthroline.

13. The tandem solar cell according to any one of claims 1 to 12, wherein: The second hole blocking material may include at least one of fullerene and its derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and SnO 2 .

14. The tandem solar cell according to any one of claims 2, 4, and 7-11, wherein: The third hole blocking layer includes 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, SnO2, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide, 2,7-bis(2,2'-bipyridin-5-yl)triphenylene, bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum, (6-(1,10-phenanthroline-3-yl)naphthalene At least one of benzophenanthroline, copper phthalocyanine, 8-hydroxyquinoline-lithium, BN-ICz-1, and 2,7-bis[N-(m-tolyl)phenylamino]-9,9'-spirobi[9H-fluorene].

15. The tandem solar cell according to any one of claims 1 to 14, wherein: The HOMO energy level of the first light absorbing layer of the first battery cell is lower than the HOMO energy level of the second light absorbing layer of the second battery cell. 16 . A photovoltaic module comprising the tandem solar cell according to claim 1 .

17. A power generation device comprising the tandem solar cell according to any one of claims 1 to 15.

18. An electrical device comprising the tandem solar cell according to any one of claims 1 to 15.

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