Solar cell and preparation method thereof, photovoltaic device, power utilization device and power generation device

Abstract

The invention discloses a solar cell and a preparation method thereof, a photovoltaic device, a power utilization device and a power generation device.The solar cell comprises a first electrode layer, a functional layer and a second electrode layer which are sequentially arranged in a stacked mode, the functional layer comprises a perovskite layer, the chemical formula of the perovskite layer is ABX3, the A ions comprise at least one of inorganic or organic or organic-inorganic mixed monovalent cations, the B ions comprise at least one of inorganic divalent cations, the X ions comprise at least one of inorganic or organic or organic-inorganic mixed monovalent anions, a passivation layer is arranged on an interface on one side of the perovskite layer, the passivation layer comprises SnOx and / or GeOx, and the value range of x is 1-2. According to the invention, the passivation layer is arranged on the interface at one side of the perovskite layer, and the passivation layer comprises SnOx and / or GeOx, thereby achieving the effect of passivating the surface of perovskite, and effectively improving the open-circuit voltage and photoelectric conversion efficiency of the cell.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a solar cell and its preparation method, a photovoltaic device, an electrical device, and a power generation device. Background Technology

[0002] Perovskite solar cells, as a third-generation solar cell, use perovskite material as the light-absorbing layer, exhibiting significant performance advantages such as high light absorption coefficient, carrier mobility, and a direct and tunable optical bandgap. However, in narrow-bandgap perovskite solar cells, the varying crystallization rates of divalent cations in the perovskite layer lead to increased surface defects, resulting in low photoelectric conversion efficiency. Summary of the Invention

[0003] In view of the above-mentioned technical problems, this application provides a solar cell and its preparation method, a photovoltaic device, an electrical device, and a power generation device to solve the problem of low photoelectric conversion efficiency of solar cells.

[0004] The first technical solution adopted in this application is: to provide a solar cell, the solar cell comprising a first electrode layer, a functional layer and a second electrode layer stacked sequentially, the functional layer comprising a perovskite layer, the chemical formula of the perovskite layer being ABX3, wherein A ions comprise at least one of inorganic or organic or organic-inorganic mixed monovalent cations, B ions comprise at least one of inorganic divalent cations, and X ions comprise at least one of inorganic or organic or organic-inorganic mixed monovalent anions, a passivation layer is provided on one side interface of the perovskite layer, the passivation layer comprising SnOx and / or GeOx, wherein the value of x ranges from 1 to 2.

[0005] In the technical solution of this application embodiment, the solar cell is a narrow bandgap perovskite solar cell. The chemical formula of the perovskite layer is ABX3, and the B ions include at least one of the inorganic divalent cations. Due to the different crystallization nucleation rates of the divalent cations, some divalent cations are enriched on the perovskite surface. A passivation layer including SnOx and / or GeOx is provided on the perovskite surface, which can passivate the perovskite and thereby improve the photoelectric conversion efficiency of the solar cell.

[0006] In some embodiments, the chemical formula of the perovskite layer can also be A(Sn) a Pb 1-a-b M b X3, wherein M ion includes at least one of inorganic divalent cations, a ranges from 0.4 to 0.6, and b ranges from 0 to 0.1.

[0007] In the technical solution of this application embodiment, the inorganic divalent cation in the chemical formula of the perovskite layer includes Sn. 2+ and Pb 2+Because Sn 2+ The crystallization nucleation rate is faster than that of Pb. 2+ , making Sn 2+ Enriching the perovskite surface and oxidizing the Sn atoms enriched on the perovskite surface to form SnOx can passivate the perovskite layer, thus forming a passivation layer on one side of the perovskite layer. This not only passivates perovskite surface defects, especially tin-type defects, but also reduces recombination centers, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0008] In some implementations, the mass ratio of Sn to Pb in element B ranges from 4:6 to 6:4.

[0009] In the technical solution of this application embodiment, the mass ratio of Sn and Pb elements is within the above range, which is beneficial to forming a narrow bandgap perovskite solar cell with high stability and high photoelectric conversion efficiency.

[0010] In some implementations, the thickness of the passivation layer is greater than or equal to 0.1 nm and less than or equal to 10 nm.

[0011] In the technical solution of this application embodiment, the thickness of the passivation layer is within the above-mentioned range, which will not generate new interfaces and can form a relatively thin passivation layer. While passivating the perovskite surface defects, it reduces recombination centers and increases the open-circuit voltage of the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell.

[0012] In some implementations, the thickness of the passivation layer is greater than or equal to 0.1 nm and less than or equal to 3 nm.

[0013] In the technical solution of this application embodiment, the thickness of the passivation layer is within the above-mentioned range, which will not generate new interfaces and can form a relatively thin passivation layer. While passivating the perovskite surface defects, it reduces recombination centers and increases the open-circuit voltage of the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell.

[0014] In some implementations, the molar ratio of Sn to B at the interface of the perovskite layer toward the passivation layer is greater than the molar ratio of Sn to B inside the perovskite layer.

[0015] In the technical solution of this application embodiment, the chemical formula of the perovskite layer is ABX3, and the B ions include Sn. 2+ and Pb 2+ Because Sn 2+ The crystallization nucleation rate is faster than that of Pb. 2+ , making Sn 2+The Sn atoms enriched on the perovskite surface are more abundant in the perovskite layer than in the perovskite layer itself. The Sn atoms enriched on the perovskite surface are oxidized to form SnOx, which can then act as a passivation layer, thus forming a passivation layer on one side of the perovskite layer.

[0016] In some embodiments, the A ion comprises a monovalent metal cation and / or a monovalent organic cation, wherein the monovalent metal cation includes Li. + Na + K + 、Rb + and Cs + One or more of the following, wherein the monovalent organic cation includes one or more of organic amine ions, formamidinium ions, and imidazole ions; and / or, the B ion includes Sn 2+ Pb 2+ Zn 2+ Ti 2+ Ni 2+ Fe 2 + Co 2+ Cu 2+ Ga 2+ 、Ge 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ In 2+ Mn 2+ Cr 2+ Mo 2+ and Eu 2+ At least one of the following, X ions include one or more of halide ions and halide-like ions, X ions include F - Cl - ,Br - I - CN - CH3COO - SCN - BF4 - SeCN - PF6 - One or more of them.

[0017] In some embodiments, the band gap of the perovskite layer is 1.2 eV to 1.4 eV.

[0018] In the technical solution of this application embodiment, the solar cell is a narrow bandgap perovskite solar cell. The bandgap of the perovskite layer is within the above-mentioned range, which enables the perovskite to absorb photons of lower energy, thereby expanding the range of solar spectrum available to the solar cell and helping to improve photoelectric conversion efficiency.

[0019] In some embodiments, the solar cell further includes a hole transport layer and / or an electron transport layer, wherein one of the hole transport layer and the electron transport layer is disposed on the side of the perovskite layer away from the passivation layer, and the other of the hole transport layer and the electron transport layer is disposed on the side of the passivation layer away from the perovskite layer.

[0020] In the technical solution of this application embodiment, the solar cell includes a conventional solar cell and a reverse solar cell. A hole transport layer is disposed on the side of the perovskite layer away from or near the passivation layer, and an electron transport layer is disposed on the other side. The hole transport layer promotes the transport of photogenerated holes from the perovskite layer to the first electrode layer, while blocking the reverse flow of electrons, which helps to reduce charge recombination and improve the photoelectric conversion efficiency of the solar cell. The electron transport layer transports separated electrons to the second electrode layer, while blocking the reverse flow of holes, which helps to improve the photoelectric conversion efficiency and reduce carrier recombination. The role of the hole transport layer and the electron transport layer in the solar cell is to promote the effective transport of photogenerated carriers and reduce charge recombination, thereby improving the photoelectric conversion efficiency.

[0021] The second technical solution adopted in this application is: providing a method for preparing a solar cell, for preparing any of the above-mentioned solar cells, comprising: providing one of a first electrode layer or a second electrode layer; disposing a perovskite layer on one of the first electrode layer or the second electrode layer, the perovskite layer having the chemical formula ABX3, wherein A ions include at least one of inorganic or organic or organic-inorganic mixed monovalent cations, B ions include at least one of inorganic divalent cations, and X ions include at least one of inorganic or organic or organic-inorganic mixed monovalent anions; forming a passivation layer on the surface of the perovskite layer, the passivation layer including SnOx and / or GeOx, wherein the value of x ranges from 1 to 2; and disposing one of the first electrode layer or the second electrode layer on the passivation layer.

[0022] In the technical solution of this application embodiment, the passivation layer on the surface of the perovskite layer is prepared by using the preparation method provided above, which can passivate perovskite surface defects, especially tin-type defects, reduce recombination centers, and thereby improve the photoelectric conversion efficiency of the solar cell.

[0023] In some embodiments, the step of forming a passivation layer on the surface of the perovskite layer includes: oxidizing Sn atoms on the surface of the perovskite layer to form SnOx.

[0024] In the technical solution of this application embodiment, oxidizing Sn atoms enriched on the perovskite surface to form SnOx can play a passivation role, thereby forming a passivation layer on one side interface of the perovskite layer.

[0025] In some embodiments, the step of forming a passivation layer on the surface of the perovskite layer includes: introducing an O source, introducing a Sn source and / or a Ge source, and forming SnOx and / or GeOx on the surface of the perovskite layer.

[0026] In the technical solutions of this application embodiment, when the Sn atom content enriched on the perovskite surface is low, SnOx is formed by introducing O and Sn sources. And / or GeOx is formed by introducing O and Ge sources, thereby forming a passivation layer on one side interface of the perovskite layer.

[0027] In some embodiments, the O source includes at least one of air, oxygen (O2), water (H2O), hydrogen peroxide (H2O2), and tin oxide (SnOx); and / or the Sn source includes at least one of stannous chloride (SnCl2·2H2O), stannous chloride (SnCl4), stannous sulfate (SnSO4), tetra(dimethylamino)tin (IV) (TDMASn), tin (Sn), and tin oxide (SnOx); and / or the Ge source includes at least one of germanium tetrachloride (GeCl4), germanium (Ge), and germanium oxide (GeOx).

[0028] In the technical solutions of this application embodiment, by utilizing the O source, Sn source and / or Ge source listed above, a passivation layer can be formed without generating a new interface, thereby reducing perovskite surface defects and improving the photoelectric conversion efficiency of solar cells.

[0029] In some embodiments, a passivation layer is formed on the surface of the perovskite layer by at least one of atomic layer deposition, plasma deposition, vacuum evaporation and physical vapor deposition.

[0030] In the technical solutions of this application embodiment, by using the preparation methods listed above, a thin passivation layer can be formed on one side interface of the perovskite layer, reducing perovskite surface defects and improving the photoelectric conversion efficiency of the solar cell.

[0031] The third technical solution adopted in this application is: to provide a photovoltaic device, including the solar cell as described above or a method for preparing the solar cell as described above.

[0032] The fourth technical solution adopted in this application is: to provide an electrical device, including the solar cell as described above or a method for preparing the solar cell as described above.

[0033] Since the device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0034] The fifth technical solution adopted in this application is: providing a solar cell including the solar cell described above or a method for preparing a solar cell including the solar cell described above.

[0035] Since the device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0036] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above contents and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0038] Figure 1 This is a schematic diagram of the structure of a solar cell according to an embodiment of this application;

[0039] Figure 2 This is a schematic diagram of the structure of a solar cell according to an embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the structure of a solar cell according to an embodiment of this application;

[0041] Figure 4 This is a schematic diagram of the structure of a photovoltaic device according to an embodiment of this application;

[0042] Figure 5 This is a schematic diagram of the structure of an electrical device according to an embodiment of this application;

[0043] Figure 6 This is a schematic diagram of the structure of a power generation device according to an embodiment of this application;

[0044] Figure 7 This is a schematic diagram of the Sn / Pb elemental ratio according to an embodiment of this application.

[0045] Marker explanation:

[0046] Solar cell 100, first electrode layer 101, functional layer 102, second electrode layer 103, perovskite layer 1021, passivation layer 1022, electron transport layer 1023, hole transport layer 1024, photovoltaic device 1000, power consumption device 2000, power generation device 3000. Detailed Implementation

[0047] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0049] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0050] 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 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.

[0051] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0052] In narrow bandgap tin-lead perovskite solar cells, Sn 2+ The Lewis acidity is relatively stronger than that of Pb. 2+ This led to Sn 2+ The crystallization nucleation rate is faster than that of Pb. 2+ Because Sn 2+ The inherent tendency for faster nucleation, more Sn 2+ The formation of a tin-rich thin film on the perovskite surface amplifies surface defects, leading to low photoelectric conversion efficiency in solar cells. In some implementations, molecular passivation or field passivation can be used to passivate the perovskite to improve the turn-on voltage of the solar cell, but this technology is relatively complex.

[0053] Reference Figure 1 This application provides a solar cell 100, which includes a first electrode layer 101, a functional layer 102, and a second electrode layer 103 stacked sequentially. The functional layer 102 includes a perovskite layer 1021 with the chemical formula ABX3. In this perovskite layer 1021, A ions include at least one of inorganic, organic, or mixed organic-inorganic monovalent cations, B ions include at least one of inorganic divalent cations, and X ions include at least one of inorganic, organic, or mixed organic-inorganic monovalent anions. A passivation layer 1022 is disposed on one side interface of the perovskite layer 1021. The passivation layer 1022 includes SnOx and / or GeOx, wherein the value of x ranges from 1 to 2.

[0054] In the technical solution of this application embodiment, the solar cell 100 is a narrow bandgap perovskite solar cell, the chemical formula of the perovskite layer 1021 is ABX3, the B ions include at least one of inorganic divalent cations. Due to the different crystallization nucleation rates of divalent cations, some divalent cations are enriched on the perovskite surface. A passivation layer including SnOx and / or GeOx is provided on the perovskite surface, which can passivate the perovskite and thereby improve the photoelectric conversion efficiency of the solar cell.

[0055] The passivation layer 1022 includes SnOx and / or GeOx, wherein the value of x can be 1, 1.1, 1.15, 1.2, 1.5, 1.58, 1.68, 1.76, 1.8, 1.9, 1.98, 2, etc., or a range of any two of the above values, such as 1 to 1.58, 1.58 to 2, 1.2 to 1.76, 1.68 to 2, etc.

[0056] The passivation layer 1022 comprises SnOx and / or GeOx, wherein the molar ratio of SnOx to GeOx ranges from 1:0 to 0:1. The molar ratio can be 1:0, 0.9:0.1, 0.8:0.2, 0.7:0.3, 0.6:0.4, 0.5:0.5, 0.4:0.6, 0.2:0.8, 0:1, or any range of two of the above values, such as 1:0 to 0.6:0.4, 0.6:0.4 to 0:1, 0.5:0.5 to 0.2:0.8, 0.7:0.3 to 0.4:0.6, etc. When the molar ratio of SnOx to GeOx is within the above range, it can passivate perovskite surface defects, especially tin-type defects, and reduce recombination centers, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0057] In some embodiments, the chemical formula of the perovskite layer can also be A(Sn) a Pb 1-a-b M bX3, wherein M ion includes at least one of inorganic divalent cations, a ranges from 0.4 to 0.6, and b ranges from 0 to 0.1.

[0058] In the technical solution of this application embodiment, the inorganic divalent cation in the chemical formula of the perovskite layer includes Sn. 2+ and Pb 2+ Because Sn 2+ The crystallization nucleation rate is faster than that of Pb. 2+ , making Sn 2+ Enriching the perovskite surface and oxidizing the Sn atoms enriched on the perovskite surface to form SnOx can passivate the perovskite layer, thus forming a passivation layer on one side of the perovskite layer. This not only passivates perovskite surface defects, especially tin-type defects, but also reduces recombination centers, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0059] The value of 'a' can be 0.4, 0.45, 0.48, 0.5, 0.52, 0.55, 0.58, 0.6, etc., or a range of any two of the above values, such as 0.4~0.52, 0.52~0.6, 0.48~0.58, 0.5~0.6, etc.

[0060] The value of b can be 0, 0.01, 0.02, 0.05, 0.06, 0.07, 0.08, 0.1, etc., or a range of any two of the above values, such as 0~0.05, 0.05~0.07, 0.07~0.1, 0.02~0.08, etc.

[0061] In some implementations, the mass ratio of Sn to Pb in element B ranges from 4:6 to 6:4.

[0062] In the technical solution of this application embodiment, the mass ratio of Sn and Pb elements is within the above-mentioned range, which is beneficial for forming a narrow bandgap perovskite solar cell with high stability and high photoelectric conversion efficiency. The mass ratio of Sn and Pb elements can be 4:6, 5:5, 6:4, etc., or a range composed of any two of the above values, such as 4:6 to 5:5, 5:5 to 6:4, etc.

[0063] In some embodiments, the thickness of the passivation layer 1022 is greater than or equal to 0.1 nm and less than or equal to 10 nm.

[0064] In the technical solution of this application embodiment, the thickness of the passivation layer 1022 is within the above range, so that no new interface is generated and a relatively thin passivation layer 1022 can be formed. While passivating the perovskite surface defects, it reduces recombination centers and increases the open circuit voltage of the solar cell 100, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0065] The thickness of the passivation layer 1022 can be 0.1nm, 0.2nm, 0.5nm, 1nm, 1.5nm, 2nm, 2.5nm, 3.1nm, 3.6nm, 4.2nm, 4.5nm, 5.5nm, 6nm, 7.5nm, 8.3nm, 8.8nm, 9nm, 9.5nm, 9.8nm, 10nm, etc., or a range of any two of the above values, such as 0.1nm~1.5nm, 1.5nm~3.6nm, 3.6nm~8.8nm, 8.8nm~10nm, 2nm~5.5nm, 7.5nm~9nm, etc.

[0066] In some implementations, the thickness of the passivation layer 1022 is greater than or equal to 0.1 nm and less than or equal to 3 nm.

[0067] In the technical solution of this application embodiment, the thickness of the passivation layer 1022 is within the above range, so that no new interface is generated and a relatively thin passivation layer 1022 can be formed. While passivating the perovskite surface defects, it reduces recombination centers and increases the open circuit voltage of the solar cell 100, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0068] The thickness of the passivation layer 1022 can be 0.1nm, 0.12nm, 0.2nm, 0.25nm, 0.33nm, 0.38nm, 0.45nm, 0.5nm, 0.6nm, 0.68nm, 0.7nm, 0.78nm, 0.82nm, 0.85nm, 0.9nm, 0.95nm, 0.98nm, 1nm, 1.5nm, 1.9nm, 2.2nm, 2.6nm, 2. 8nm, 3nm, or any range of two of the above values, such as 0.1nm~0.05nm, 0.05nm~0.45nm, 0.45nm~0.85nm, 0.85nm~1nm, 0.2nm~0.6nm, 0.25nm~0.98nm, 0.98nm~2.2nm, 2.2nm~1nm, 0.2nm~0.6nm, 0.25nm~0.98nm, etc.

[0069] In some embodiments, the molar ratio of Sn to B at the interface of the perovskite layer 1021 toward the passivation layer 1022 is greater than the molar ratio of Sn to B inside the perovskite layer 1021.

[0070] In the technical solution of this application embodiment, the chemical formula of the perovskite layer 1021 is ABX3, and the B ions include Sn. 2+ and Pb 2 + Because Sn 2+ The crystallization nucleation rate is faster than that of Pb. 2+, making Sn 2+ The Sn atoms enriched on the perovskite surface are present in a higher molar ratio of Sn to B at the interface of the perovskite layer 1021 facing the passivation layer 1022 than the Sn atoms inside the perovskite layer 1021. The Sn atoms enriched on the perovskite surface are oxidized to form SnOx, which can play a passivation role, thus forming the passivation layer 1022 on one side of the interface of the perovskite layer 1021.

[0071] In this embodiment, the molar ratio of Sn to B at the interface of the perovskite layer 1021 facing the passivation layer 1022 is greater than that inside the perovskite layer 1021. The XPS standard test method for Sn element distribution involves: disassembling the battery to the perovskite layer, cutting the sample into 5cm × 5cm pieces, and using XPS to etch the prepared sample from the perovskite surface at 0s, 500s, and 1000s, respectively, and performing narrow-spectrum scanning to obtain the elemental distribution at different depths, thereby calculating the Sn / Pb elemental ratio. In one embodiment, referring to... Figure 7 0s represents the perovskite surface, and the Sn / Pb ratio is much higher than that of the interior (500s, 1000s), indicating that the surface of the perovskite is rich in Sn.

[0072] In some embodiments, the A ion comprises a monovalent metal cation and / or a monovalent organic cation, wherein the monovalent metal cation includes Li. + Na + K + 、Rb + and Cs + One or more of the following, wherein the monovalent organic cation includes one or more of organic amine ions, formamidinium ions, and imidazole ions; and / or, the B ion includes Sn 2+ Pb 2+ Zn 2+ Ti 2+ Ni 2+ Fe 2 + Co 2+ Cu 2+ Ga 2+ 、Ge 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ In 2+ Mn 2+ Cr 2+ Mo 2+ and Eu 2+ At least one of the following, X ions include one or more of halide ions and halide-like ions, X ions include F -Cl - ,Br - I - CN - CH3COO - SCN - BF4 - SeCN - PF6 - One or more of them.

[0073] In some embodiments, the band gap of the perovskite layer 1021 is 1.2 eV to 1.4 eV.

[0074] In the technical solution of this application embodiment, the solar cell 100 is a narrow bandgap perovskite solar cell 100. The bandgap of the perovskite layer 1021 is within the above-mentioned range, which enables the perovskite to absorb photons of lower energy, thereby expanding the usable range of the solar spectrum for the solar cell 100 and helping to improve the photoelectric conversion efficiency.

[0075] The band gap of the perovskite layer 1021 can be 1.2 eV, 1.22 eV, 1.25 eV, 1.3 eV, 1.35 eV, 1.38 eV, 1.4 eV, or any range of two of the above values, such as 1.2 eV to 1.25 eV, 1.25 eV to 1.35 eV, 1.35 eV to 1.4 eV, 1.22 eV to 1.3 eV, etc.

[0076] In some implementations, refer to Figure 2 and Figure 3 The solar cell 100 also includes a hole transport layer 1024 and / or an electron transport layer 1023. One of the hole transport layer 1024 and the electron transport layer 1023 is disposed on the side of the perovskite layer 1021 away from the passivation layer 1022, and the other of the hole transport layer 1024 and the electron transport layer 1023 is disposed on the side of the passivation layer 1022 away from the perovskite layer 1021.

[0077] In the technical solution of this application embodiment, the solar cell 100 includes a conventional solar cell and a reverse solar cell. One of a hole transport layer 1024 and an electron transport layer 1023 is disposed on the side of the perovskite layer 1021 away from the passivation layer 1022, and the other of the hole transport layer 1024 and electron transport layer 1023 is disposed on the side of the passivation layer 1022 away from the perovskite layer 1021. The hole transport layer 1024 promotes the transport of photogenerated holes from the perovskite layer 1021 to one side of the electrode layer, while blocking the reverse flow of electrons, thus helping to reduce charge recombination and improve the photoelectric conversion efficiency of the solar cell 100. The electron transport layer 1023 transports separated electrons to the other side of the electrode layer, while blocking the reverse flow of holes, thus helping to improve the photoelectric conversion efficiency and reduce carrier recombination. The role of the hole transport layer 1024 and the electron transport layer 1023 in the solar cell 100 is to promote the effective transport of photogenerated carriers and reduce charge recombination, thereby improving the photoelectric conversion efficiency.

[0078] The first electrode layer 101 includes a transparent conductive substrate. The transparent conductive substrate is used to extract photogenerated carriers. The transparent conductive substrate includes, but is not limited to, one of the following materials: FTO (fluorine-doped tin oxide), ITO (indium tin oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), and IZO (indium-doped zinc oxide).

[0079] Electron transport layer 1023 performs the function of extracting electrons and blocking holes. Electron transport layer 1023 is at least one of the following materials and their derivatives, or materials obtained by doping or passivation: [6,6]-phenyl C 61 Methyl butyrate (PC) 61 BM), [6,6]-phenyl C 71 Methyl butyrate (PC) 71 BM), fullerene C60 (C60), fullerene C70 (C70), tin dioxide (SnO2), zinc oxide (ZnO), etc.

[0080] The hole transport layer 1024 is at least one of the following materials and their derivatives, or materials obtained by doping or passivation: nickel oxide, 2,2',7,7'-tetratetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene (Spiro-OMeTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate (Me-4PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphate (MeO-4PACz), and other materials that have been reported in patents or literature.

[0081] The material of the second electrode layer 103 is an organic, inorganic, or organic-inorganic mixed conductive material, including but not limited to one or more of the following materials: Ag, Cu, C, Au, Al, ITO, AZO, BZO, and IZO.

[0082] It should be noted that corresponding modification layers can be inserted between the layers. For example, a hole blocking layer for blocking holes can be inserted on the side of the electron transport layer 1023 away from the perovskite layer 1021. The material can include SnO2, copper bath (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, BCP), etc.

[0083] The second technical solution adopted in this application is: providing a method for preparing a solar cell 100, for preparing any of the above-mentioned solar cells 100, comprising: providing one of a first electrode layer 101 or a second electrode layer 103; depositing a perovskite layer 1021 on one of the first electrode layer 101 or the second electrode layer 103, the perovskite layer 1021 having the chemical formula ABX3, wherein A ions include at least one of inorganic or organic or organic-inorganic mixed monovalent cations, B ions include at least one of inorganic divalent cations, and X ions include at least one of inorganic or organic or organic-inorganic mixed monovalent anions; forming a passivation layer 1022 on the surface of the perovskite layer 1021, the passivation layer 1022 including SnOx and / or GeOx, wherein the value of x ranges from 1 to 2; and depositing the other of the first electrode layer 101 or the second electrode layer 103 on the passivation layer 1022.

[0084] In the technical solution of this application embodiment, the passivation layer 1022 on the surface of the perovskite layer 1021 is prepared using the preparation method provided above. This can passivate perovskite surface defects, especially tin-type defects, and reduce recombination centers, thereby improving the photoelectric conversion efficiency of the solar cell 100. The passivation layer 1022 includes SnOx and / or GeOx, wherein the value of x can be 1, 1.1, 1.15, 1.2, 1.5, 1.58, 1.68, 1.76, 1.8, 1.9, 1.98, 2, etc., or a range of any two of the above values, such as 1 to 1.58, 1.58 to 2, 1.2 to 1.76, 1.68 to 2, etc.

[0085] In some embodiments, the step of forming a passivation layer 1022 on the surface of the perovskite layer 1021 includes: oxidizing Sn atoms on the surface of the perovskite layer 1021 to form SnOx.

[0086] In the technical solution of this application embodiment, oxidizing Sn atoms enriched on the perovskite surface to form SnOx can play a passivation role, thereby forming a passivation layer 1022 on one side interface of the perovskite layer 1021.

[0087] In some embodiments, the step of forming a passivation layer 1022 on the surface of the perovskite layer 1021 includes: introducing an O source, introducing a Sn source and / or a Ge source, and forming SnOx and / or GeOx on the surface of the perovskite layer 1021.

[0088] In the technical solution of this application embodiment, when the Sn atom content enriched on the perovskite surface is low, SnOx is formed by introducing O source and Sn source. And / or GeOx is formed by introducing O source and Ge source, thereby forming a passivation layer 1022 on one side interface of perovskite layer 1021.

[0089] In some embodiments, the O source includes at least one of air, oxygen (O2), water (H2O), hydrogen peroxide (H2O2), and tin oxide (SnOx); and / or the Sn source includes at least one of stannous chloride (SnCl2·2H2O), stannous chloride (SnCl4), stannous sulfate (SnSO4), tetra(dimethylamino)tin (IV) (TDMASn), tin (Sn), and tin oxide (SnOx); and / or the Ge source includes at least one of germanium tetrachloride (GeCl4), germanium (Ge), and germanium oxide (GeOx).

[0090] In the technical solution of this application embodiment, by using the O source, Sn source and / or Ge source listed above, a passivation layer 1022 can be formed without generating a new interface, thereby reducing perovskite surface defects and improving the photoelectric conversion efficiency of the solar cell 100.

[0091] In some embodiments, a passivation layer 1022 is formed on the surface of the perovskite layer 1021 by at least one of atomic layer deposition, plasma deposition, vacuum evaporation and physical vapor deposition.

[0092] In the technical solution of this application embodiment, by using the preparation method listed above, a thin passivation layer 1022 can be formed on one side interface of the perovskite layer 1021, reducing perovskite surface defects and improving the photoelectric conversion efficiency of the solar cell 100.

[0093] The third technical solution adopted in this application is: to provide a photovoltaic device, including the solar cell 100 as described above or a method for preparing the solar cell 100 as described above.

[0094] The fourth technical solution adopted in this application is: to provide an electrical device, including the solar cell 100 as described above or a method for preparing the solar cell 100 as described above.

[0095] Reference Figure 4This application also provides a photovoltaic device 1000, including the solar cell 100 as described above or the solar cell 100 prepared by the method described above.

[0096] See Figure 5 This application also provides an electrical device 2000, including the solar cell 100 as described above or the solar cell 100 prepared by the method described above.

[0097] In this application, the solar cell 100 serves as the power source for the aforementioned electrical device 2000; alternatively, the solar cell 100 can serve as an energy storage unit for the aforementioned electrical device 2000. As an example, the electrical device 2000 can be a lighting element, a display element, or an automobile, etc.

[0098] See Figure 6 This application also provides a power generation device 3000, including the solar cell 100 as described above or the solar cell 100 prepared by the method described above. The power generation device 3000 may include the solar cell 100 and an energy storage device, which may be a secondary battery.

[0099] To make the technical problems, technical solutions, and beneficial effects solved by the embodiments of this application clearer, the following will provide a more detailed description in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0100] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0101] Example 1:

[0102] (1) Preparation of the first electrode layer: The glass on which the transparent conductive film (fluorine-doped tin oxide FTO with a thickness of 600 nm) has been prepared is cleaned by acetone-alcohol-deionized water in sequence; after drying, it is ready for the next step.

[0103] (2) Preparation of hole transport layer: Take 100 μL of polystyrene sulfonate solution and drop it onto the substrate of the first electrode layer. Spin coat at 3000 rpm / s for 30 s. After spin coat, transfer to a hot plate at 150℃ for annealing for 20 min to obtain a hole transport layer with a thickness of 30 nm.

[0104] (3) Preparation of the perovskite layer: 217 mg FAI, 86 mg MAI, 415 mg PbI2, 335 mg SnI2, 23 mg SnF2, and 1 mmol% organic thiocyanate additive were added to the prepared perovskite precursor solvent and stirred at 800 rpm for 3 h on a magnetic stirrer. 100 μL of the prepared precursor was dropped onto the hole transport layer at 1500 rpm for 10 s, followed by spin coating at 1000 rpm / s and 4000 rpm for 40 s. At approximately 30 s, 350 μL of ethyl acetate was dropped or vacuum flash evaporation was performed for 50 s. Finally, the spin-coated perovskite was annealed on a hot plate at 100 °C for 10 min to obtain a FA layer with a thickness of 0.9 μm. 0.7 MA 0.3 Sn 0.5 Pb 0.5 I3 perovskite layer.

[0105] (4) Preparation of passivation layer: A 1 nm thick SnO layer was prepared on the perovskite layer by ALD. 1.92 .

[0106] (5) Preparation of electron transport layer / modification layer / second electrode: 25nm C60 (electron transport layer) / 7nm BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, modification layer) / 80nm Cu were deposited on the passivation layer using vapor deposition equipment.

[0107] Example 2

[0108] Similar to Example 1, the difference is:

[0109] Step (4) of Example 1 is adjusted to: a SnO layer with a thickness of 1 nm is prepared on the perovskite layer by vacuum evaporation. 1.92 .

[0110] Example 3

[0111] Similar to Example 1, the difference is:

[0112] Step (4) of Example 1 is modified to: a 5 nm thick SnO layer is prepared on the perovskite layer by ALD. 1.92 .

[0113] Example 4

[0114] Similar to Example 1, the difference is:

[0115] Step (4) of Example 1 is modified to: a 10 nm thick SnO layer is prepared on the perovskite layer by ALD. 1.92 .

[0116] Example 5

[0117] Similar to Example 1, the difference is:

[0118] Step (4) of Example 1 is modified to: a GeO layer with a thickness of 1 nm is prepared on the perovskite layer by ALD. 1.92 .

[0119] Example 6

[0120] Similar to Example 1, the difference is:

[0121] Step (4) of Example 1 is adjusted to: a GeO layer with a thickness of 1 nm is prepared on the perovskite layer by vacuum evaporation. 1.92 .

[0122] Example 7

[0123] Similar to Example 1, the difference is:

[0124] Step (4) of Example 1 is modified to: a 5 nm thick GeO layer is prepared on the perovskite layer by ALD. 1.92 .

[0125] Example 8

[0126] Similar to Example 1, the difference is:

[0127] Step (4) of Example 1 is modified to: a 10 nm thick GeO layer is prepared on the perovskite layer by ALD. 1.92 .

[0128] Example 9

[0129] Similar to Example 1, the difference is:

[0130] Step (4) of Example 1 is modified to: a 5 nm thick SnO layer is prepared on the perovskite layer by ALD. 1.92 and a thickness of 5nm GeO 1.92 .

[0131] Example 10

[0132] Similar to Example 1, the difference is:

[0133] Step (4) of Example 1 is modified to: a SnO layer with a thickness of 0.5 nm is prepared on the perovskite layer by ALD. 1.92 and a thickness of 0.5nm GeO 1.92 .

[0134] Comparative Example 1

[0135] Similar to Example 1, the difference is:

[0136] Step (4) of Example 1 is not included.

[0137] Battery performance tests were conducted on the battery devices 1 to 11 obtained from Examples 1 to 10 and Comparative Example 1, and the results are shown in Table 1.

[0138] Test method:

[0139] 1. Photoelectric conversion efficiency test method: Under standard simulated sunlight (AM1.5G, 100mW / cm²), 2 Under irradiation, battery performance is tested to obtain the IV curve. Based on the IV curve and data from the testing equipment, the short-circuit current Jsc (unit: mA / cm²) can be calculated. 2 The open-circuit voltage Voc (in V), maximum light output current Jmpp (in mA), and maximum light output voltage Vmpp (in V) are given. The fill factor FF (in %) is calculated using the formula FF = Jsc × Voc / (Jmpp × Vmpp). The photoelectric conversion efficiency PCE (in %) is calculated using the formula PCE = Jsc × Voc × FF / Pw; Pw represents the input power (in mW).

[0140] Table 1 Battery Performance Tests (IV Tests)

[0141]

[0142] As can be seen from the data in Table 1, all solar cell devices in Examples 1-10 have a passivation layer formed on the surface of the perovskite layer. The passivation layer includes SnOx and / or GeOx, and their photoelectric conversion efficiency is higher than that of Comparative Example 1. This shows that the preparation method provided in this application can passivate the perovskite surface of the solar cell, effectively improving the open-circuit voltage and photoelectric conversion efficiency of the cell.

[0143] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A solar cell, characterized in that, The solar cell includes a first electrode layer, a functional layer, and a second electrode layer stacked sequentially. The functional layer includes a perovskite layer with the chemical formula ABX3, wherein A ions include at least one inorganic, organic, or mixed organic-inorganic monovalent cation, B ions include at least one inorganic divalent cation, and X ions include at least one inorganic, organic, or mixed organic-inorganic monovalent anion. A passivation layer is provided on one side interface of the perovskite layer, and the passivation layer includes SnOx and / or GeOx, wherein the value of x ranges from 1 to 2.

2. The solar cell as described in claim 1, characterized in that, The chemical formula of the perovskite layer can also be A(Sn) a Pb 1-a-b M b X3, wherein M ion includes at least one of inorganic divalent cations, a ranges from 0.4 to 0.6, and b ranges from 0 to 0.

1.

3. The solar cell as described in claim 1 or 2, characterized in that, In element B, the mass ratio of Sn to Pb ranges from 4:6 to 6:

4.

4. The solar cell according to any one of claims 1 to 3, characterized in that, The thickness of the passivation layer is greater than or equal to 0.1 nm and less than or equal to 10 nm.

5. The solar cell as described in claim 4, characterized in that, The thickness of the passivation layer is greater than or equal to 0.1 nm and less than or equal to 3 nm.

6. The solar cell according to any one of claims 1 to 5, wherein the molar ratio of Sn element in B element at the interface of the perovskite layer toward the passivation layer is greater than the molar ratio of Sn element in B element inside the perovskite layer.

7. The solar cell according to any one of claims 1 to 6, characterized in that, The A ion includes a monovalent metal cation and / or a monovalent organic cation, the monovalent metal cation including Li + Na + K + 、Rb + and Cs + One or more of the following, wherein the monovalent organic cation includes one or more of organic amine ions, formamidinium ions, and imidazole ions; and / or, the B ion includes Sn. 2+ Pb 2+ Zn 2+ Ti 2+ Ni 2+ Fe 2+ Co 2+ Cu 2+ Ga 2+ 、Ge 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2 + In 2+ Mn 2+ Cr 2+ Mo 2+ and Eu 2+ At least one of the following, wherein the X ion comprises one or more of halide ions and halide-like ions, and the X ion comprises F - Cl - ,Br - I - CN - CH3COO - SCN - BF4 - SeCN - PF6 - One or more of them.

8. The solar cell according to any one of claims 1 to 7, characterized in that, The band gap of the perovskite layer is 1.2 eV to 1.4 eV.

9. The solar cell according to any one of claims 1 to 8, characterized in that, The solar cell further includes a hole transport layer and / or an electron transport layer, wherein one of the hole transport layer and the electron transport layer is disposed on the side of the perovskite layer away from the passivation layer, and the other of the hole transport layer and the electron transport layer is disposed on the side of the passivation layer away from the perovskite layer.

10. A method for preparing a solar cell, characterized in that, include: Provide one of a first electrode layer or a second electrode layer; A perovskite layer is disposed on one of the first electrode layer or the second electrode layer. The chemical formula of the perovskite layer is ABX3, wherein A ions include at least one of inorganic or organic or organic-inorganic mixed monovalent cations, B ions include at least one of inorganic divalent cations, and X ions include at least one of inorganic or organic or organic-inorganic mixed monovalent anions. A passivation layer is formed on the surface of the perovskite layer, the passivation layer comprising SnOx and / or GeOx, wherein the value of x ranges from 1 to 2; The passivation layer may be provided with either the first electrode layer or the second electrode layer.

11. The method for preparing a solar cell as described in claim 10, characterized in that, The step of forming a passivation layer on the surface of the perovskite layer includes: oxidizing Sn atoms on the surface of the perovskite layer to form SnOx.

12. The method for preparing a solar cell as described in claim 11, characterized in that, The step of forming a passivation layer on the surface of the perovskite layer includes: introducing an O source, introducing a Sn source and / or a Ge source, and forming SnOx and / or GeOx on the surface of the perovskite layer.

13. The method for fabricating a solar cell according to claim 12, wherein the O source comprises at least one selected from air, oxygen, water, hydrogen peroxide, and tin oxide; and / or The Sn source includes at least one of stannous chloride, stannous tetrachloride, stannous sulfate, tetra(dimethylamino)stannous(IV), tin, and tin oxide; and / or The Ge source includes at least one of germanium tetrachloride, germanium, and germanium oxide.

14. The method for preparing a solar cell according to any one of claims 10 to 13, wherein a passivation layer is formed on the surface of the perovskite layer by at least one of atomic layer deposition, plasma deposition, vacuum evaporation and physical vapor deposition.

15. A photovoltaic device, characterized in that, The solar cell includes any one of claims 1 to 9, or the method of preparing the solar cell includes any one of claims 10 to 14.

16. An electrical appliance, characterized in that, The solar cell includes any one of claims 1 to 9, or the method of preparing the solar cell includes any one of claims 10 to 14.

17. A power generation device, characterized in that, The solar cell includes any one of claims 1 to 9, or the method of preparing the solar cell includes any one of claims 10 to 14.

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