Solar cell, photovoltaic system, power generation device, and power utilization device

Abstract

The invention provides a solar cell, a photovoltaic system, a power generation device and a power utilization device. The solar cell comprises a substrate, an antireflection layer, a first electrode layer, a light absorption layer and a second electrode layer which are stacked in a first direction, the refractive index of the antireflection layer is between the refractive index of the substrate and the refractive index of the first electrode layer; the antireflection layer comprises a plurality of refraction layers which are arranged in a stacked mode in the first direction, and the refraction indexes of every two adjacent refraction layers are different. In the solar cell, the plurality of refraction layers are stacked, and the refractive indexes of the two adjacent refraction layers are not equal, so that the antireflection layer with the appropriate refractive index can be obtained, the refractive index of the antireflection layer is matched with the refractive indexes of the substrate and the first electrode layer, reflection of light rays entering the first electrode layer from the substrate is reduced, and the light rays are prevented from entering the first electrode layer from the substrate. Therefore, the light loss is improved and the light utilization rate of the solar cell is improved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more particularly to a solar cell, a photovoltaic system, a power generation device, and a power consumption device. Background Technology

[0002] Solar cells can convert solar energy into electrical energy, which is relatively environmentally friendly. Light utilization efficiency is an important indicator of solar cell performance. The light utilization efficiency of traditional solar cells needs further improvement. Summary of the Invention

[0003] This application provides a solar cell. The solar cell includes a substrate, an antireflection layer, a first electrode layer, a light-absorbing layer, and a second electrode layer stacked along a first direction; the refractive index of the antireflection layer is between the refractive index of the substrate and the refractive index of the first electrode layer; the antireflection layer includes a plurality of refractive layers stacked along the first direction, wherein the refractive indices of adjacent refractive layers are different.

[0004] In the aforementioned solar cell, multiple refractive layers are stacked, and the refractive indices of adjacent refractive layers are different, which can obtain an antireflection layer with a suitable refractive index. This allows the refractive index of the antireflection layer to match the refractive indices of the substrate and the first electrode layer, reducing the reflection of light when it enters the first electrode layer from the substrate. This, in turn, reduces light loss and improves the light utilization rate of the solar cell.

[0005] In some embodiments, the absolute value of the difference in refractive index between two adjacent refractive layers is 0.5 to 1.9. Since the refractive indices of two adjacent refractive layers differ significantly, when designing the antireflective layer, a multi-layer configuration can be used through optical design to obtain an antireflective layer with a large selectable equivalent refractive index range. This allows the antireflective layer to better adapt to the refractive index difference between the substrate and the first electrode layer, reducing light loss and further improving the light utilization efficiency of the solar cell.

[0006] In some embodiments, the absolute value of the difference in refractive index between two adjacent refractive layers is greater than or equal to 1 to 1.9. The larger the difference in refractive index between two adjacent refractive layers, the wider the effective refractive index range of the antireflective layer can be obtained. Considering the ease of material selection for the refractive layers, when selecting refractive layers, if the absolute value of the difference in refractive index between two adjacent refractive layers is less than or equal to 1.9, the refractive layer can be prepared using readily available materials to obtain an antireflective layer with a wide effective refractive index range.

[0007] In some embodiments, the refractive layer is made of one or more of the following materials: magnesium fluoride, silicon oxide, aluminum oxide, zinc oxide, hafnium oxide, yttrium oxide, scandium oxide, lanthanum oxide, silicon nitride, tantalum oxide, zirconium oxide, germanium oxide, titanium oxide, niobium oxide, carbon nitride, zinc selenide, and barium titanate. These materials have suitable refractive indices, and materials with suitable refractive index differences can be selected from these materials to ensure that adjacent refractive layers have a satisfactory refractive index difference, thereby obtaining an antireflective layer with a corresponding equivalent refractive index, reducing light loss, and improving the light utilization efficiency of the solar cell.

[0008] In some embodiments, the thickness of a single refractive layer is 1 nm to 10 nm. When the thickness of a single refractive layer is within this range, an antireflective layer that meets the refractive index requirements can be obtained more flexibly through the combination of multiple refractive layers, further improving the compatibility between the antireflective layer and the substrate and the first electrode layer.

[0009] In some embodiments, the number of refractive layers is 2 to 20. This range of refractive layers allows for more flexible design of the equivalent refractive index of the antireflective layer, further improving the compatibility between the antireflective layer and the substrate and the first electrode layer.

[0010] In some embodiments, the refractive index of the antireflective layer is 1.32 to 3.28. By designing the antireflective layer, a layer with a wide range of refractive indices can be obtained, allowing the refractive index of the antireflective layer to better match the refractive indices of the substrate and the first electrode layer, reducing reflection of light when it enters the first electrode layer from the substrate, and further improving the light utilization efficiency of the solar cell.

[0011] In some embodiments, the thickness of the antireflective layer is 50 nm to 200 nm. Light may experience some transmission loss when passing through the antireflective layer. A thickness within this range allows the antireflective layer to have a good antireflective effect while reducing light loss, further improving the light utilization efficiency of the solar cell. Furthermore, the thickness of the antireflective layer is also related to the thickness of the solar cell. A thickness within this range allows the solar cell to maintain a relatively small thickness, which is beneficial for further improving the overall performance of the solar cell.

[0012] In some embodiments, the refractive index of the substrate is less than the refractive index of the first electrode layer; the antireflective layer includes at least one first refractive layer and at least one second refractive layer, the refractive index of the first refractive layer is less than the refractive index of the second refractive layer, and the first and second refractive layers are alternately stacked; the layer closest to the substrate in the antireflective layer is the first refractive layer, and the layer closest to the first electrode layer in the antireflective layer is the second refractive layer. The lower refractive index of the first refractive layer is close to the lower refractive index of the substrate, and the higher refractive index of the second refractive layer is close to the higher refractive index of the first electrode layer. This results in good lattice matching between the substrate and the first refractive layer, and good lattice matching between the first electrode layer and the second refractive layer. This improves the interlayer stability between the substrate, the antireflective layer, and the first electrode layer, reduces the risk of interlayer cracking in the solar cell, and improves the cycle stability of the solar cell.

[0013] In some embodiments, the difference between the refractive index of the second refractive layer and the refractive index of the first refractive layer is 0.5 to 1.9. Within this range, the difference in refractive index between the second and first refractive layers can be flexibly adjusted by alternating layers to create an antireflection layer that is compatible with the substrate and the first electrode layer, ensuring that the equivalent refractive index of the antireflection layer meets design requirements.

[0014] In some embodiments, the refractive index of the first refractive layer is 1.32 to 1.65.

[0015] In some embodiments, the material of the first refractive layer includes one or more of magnesium fluoride, silicon oxide, and aluminum oxide.

[0016] In some embodiments, the thickness of a single first refractive layer is 1 nm to 10 nm. Within this range, the thickness of a single first refractive layer can be used to more flexibly obtain an antireflective layer that meets the refractive index requirements through the combination of multiple refractive layers, further improving the compatibility between the antireflective layer and the substrate and the first electrode layer.

[0017] In some embodiments, the refractive index of the second refractive layer is 1.85 to 3.28.

[0018] In some embodiments, the material of the second refractive layer includes one or more of zinc oxide, hafnium oxide, yttrium oxide, scandium oxide, lanthanum oxide, silicon nitride, tantalum oxide, zirconium oxide, germanium oxide, titanium oxide, niobium oxide, carbon nitride, zinc selenide, and barium titanate.

[0019] In some embodiments, the thickness of a single second refractive layer is 1 nm to 10 nm. Within this range, the thickness of a single second refractive layer can be used to more flexibly obtain an antireflective layer that meets the refractive index requirements through the combination of multiple refractive layers, further improving the compatibility between the antireflective layer and the substrate and the first electrode layer.

[0020] In some embodiments, the substrate includes a transparent substrate. Light has better transmittance through a transparent substrate, which is beneficial for further improving the light utilization efficiency of the solar cell.

[0021] In some embodiments, the surface of the substrate near the first electrode layer has a self-trapping light structure. By setting the self-trapping light structure, light reflection can be further reduced, and the light utilization efficiency of the solar cell can be improved.

[0022] In some embodiments, the light-absorbing layer includes one or more of the following: a perovskite light-absorbing layer, a silicon-based light-absorbing layer, a cadmium telluride light-absorbing layer, a gallium arsenide light-absorbing layer, and a copper indium gallium selenide light-absorbing layer. Different types of solar cells can be obtained by selecting the appropriate light-absorbing layer.

[0023] In some embodiments, the solar cell further includes one or more of a first charge extraction layer and a second charge extraction layer; the first charge extraction layer is located between the first electrode layer and the light-absorbing layer, and the second charge extraction layer is located between the second electrode layer and the light-absorbing layer; one of the first charge extraction layer and the second charge extraction layer includes a hole transport layer, and the other includes an electron transport layer.

[0024] A second aspect of this application provides a photovoltaic system. The photovoltaic system includes the solar cell of the first aspect.

[0025] A third aspect of this application provides a power generation device. The power generation device includes the solar cell of the first aspect.

[0026] A fourth aspect of this application provides an electrical device, the electrical device comprising the solar cell of the first aspect. Attached Figure Description

[0027] To more clearly illustrate the technical solution of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without any creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a solar cell in one embodiment of this application.

[0029] Explanation of markings in the diagram:

[0030] 10. Solar cell; 101. Substrate; 102. Antireflective layer; 1021. First refractive layer; 1022. Second refractive layer; 103. First electrode layer; 104. Light-absorbing layer; 105. Second electrode layer; 106. First charge extraction layer; 107. Second charge extraction layer; 108. Encapsulation layer.

[0031] To better describe and illustrate embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the currently described embodiments and / or examples, or the best mode of these inventions as currently understood. Detailed Implementation

[0032] Hereinafter, some embodiments of this application are disclosed in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0033] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims.

[0034] 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 invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0035] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0037] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0038] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, and in some embodiments, they are performed sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0039] Unless otherwise specified, in this application, the term "room temperature" generally refers to 4°C to 30°C, and optionally to 25±5°C.

[0040] Unless otherwise stated, the terms used in this application have their common meanings as commonly understood by those skilled in the art. Unless otherwise stated, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art. For example, they can be tested according to the methods given in the embodiments of this application.

[0041] During the use of solar cells, light passes through the substrate and electrodes to reach the light-absorbing layer, where it is absorbed. In this process, some light is reflected as it enters the electrodes from the substrate, reducing the amount of light reaching the light-absorbing layer. This light loss during entry from the substrate to the electrodes inhibits the improvement of the solar cell's light utilization efficiency.

[0042] Based on this, please refer to Figure 1 This application provides a solar cell 10 according to one embodiment. The solar cell 10 includes a substrate 101, an antireflection layer 102, a first electrode layer 103, a light-absorbing layer 104, and a second electrode layer 105 stacked along a first direction. The refractive index of the antireflection layer 102 is between the refractive index of the substrate 101 and the refractive index of the first electrode layer 103. The antireflection layer 102 includes a plurality of refractive layers stacked along the first direction, with adjacent refractive layers having different refractive indices. It is understood that in... Figure 1 In the diagram, the arrow indicates the first direction.

[0043] In the solar cell 10 of this embodiment, multiple refractive layers are stacked, and the refractive indices of two adjacent refractive layers are different, so that an antireflection layer 102 with a suitable equivalent refractive index can be obtained. The refractive index of the antireflection layer 102 is adapted to the refractive indices of the substrate 101 and the first electrode layer 103, thereby reducing the reflection of light when it enters the first electrode layer 103 from the substrate 101, thereby reducing light loss and improving the light utilization rate of the solar cell 10.

[0044] It is understandable that when multiple refractive layers are stacked, adjacent refractive layers will have different refractive indices. The stacking of multiple refractive layers can achieve an equivalent refractive index, which is the refractive index of the antireflection layer 102. When designing the antireflection layer 102, a suitable number of refractive layers can be selected to obtain the required equivalent refractive index, thus achieving an antireflection layer 102 that meets the refractive index requirements. This ensures that the refractive index of the antireflection layer 102 matches the refractive indices of the substrate 101 and the first electrode layer 103, reducing reflection of light when it enters the first electrode layer 103 from the substrate 101, thereby reducing light loss and improving the light utilization rate of the solar cell 10.

[0045] For different solar cells 10, there may be many types of substrates 101 and first electrode layers 103, and the difference in refractive index between the substrate 101 and the first electrode layer 103 may be large. When selecting the antireflection layer 102, if a single material is used as the antireflection layer 102 or if the antireflection layer 102 is prepared with multiple materials, the available materials are relatively limited because they need to be compatible with different types of substrates 101 and first electrode layers 103, which will restrict the widespread application of the antireflection layer 102. However, in the solar cell 10 of this embodiment, by cooperating with multiple refractive layers, the refractive index of the antireflection layer 102 can be flexibly adjusted, resulting in an antireflection layer 102 with a wider range of selectable refractive indices, thus expanding the application range of the antireflection layer 102.

[0046] In some embodiments, selecting two refractive layers made of different materials and setting an appropriate number can yield an antireflective layer 102 with a wide refractive index range. This effectively reduces the difficulty of selecting the material for the antireflective layer 102 and promotes its use in different solar cells 10.

[0047] In this application, the refractive index can be obtained by ellipsometer measurement. The multiple refractive layers of the antireflective layer, the layer structure and composition of the solar cell can be obtained by transmission electron microscopy and elemental analysis.

[0048] In some embodiments, the absolute value of the difference in refractive index between two adjacent refractive layers is 0.5 to 1.9. Since the refractive indices of two adjacent refractive layers differ significantly, when designing the antireflective layer 102, a multi-layer configuration can be used through optical design to obtain an antireflective layer 102 with a large selectable equivalent refractive index range. This allows the antireflective layer 102 to better adapt to the refractive index difference between the substrate 101 and the first electrode layer 103, reducing light loss and further improving the light utilization efficiency of the solar cell 10. Optionally, the absolute value of the difference in refractive index between two adjacent refractive layers can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or any value within the range of any two of the above values. Further optionally, the absolute value of the difference in refractive index between two adjacent refractive layers is 1 to 1.9. The greater the difference in refractive index between two adjacent refractive layers, the wider the effective refractive index range of the antireflection layer 102 can be obtained. Furthermore, considering the ease of material selection for the refractive layers, the absolute value of the difference in refractive index between two adjacent refractive layers should be less than or equal to 1.9. In this case, the antireflection layer 102 with a wide effective refractive index range can be obtained by preparing the refractive layer using readily available materials.

[0049] In some embodiments, the materials of the refractive layer include magnesium fluoride (MgF2, refractive index 1.32~1.38), silicon oxide (SiO2, refractive index 1.46), aluminum oxide (Al2O3, refractive index 1.65), zinc oxide (ZnO, refractive index 2), hafnium oxide (HfO2, refractive index 1.85~2.1), yttrium oxide (Y2O3, refractive index 2.2), scandium oxide (Sc2O3, refractive index 2.0), lanthanum oxide (La2O3, refractive index 1.88), and silicon nitride (Si3N4, refractive index 1.32~1.46). The refractive index can be selected from one or more of the following: tantalum oxide (Ta₂O₅, refractive index 2.1–2.3), zirconium oxide (ZrO₂, refractive index 2.15), germanium oxide (GeO₂, refractive index 2.2–2.4), titanium oxide (TiO₂, refractive index 2.43–2.6), niobium oxide (Nb₂O₅, refractive index 2.18), carbon nitride (1.94–3.28), zinc selenide (ZnSe, refractive index 2.4), and barium titanate (BaTiO₃, refractive index 1.91–2.0). These materials have suitable refractive indices. Materials with suitable refractive index differences can be selected from these materials to ensure that adjacent refractive layers have a satisfactory refractive index difference, thereby obtaining an antireflective layer 102 with a corresponding equivalent refractive index, reducing light loss, and improving the light utilization efficiency of the solar cell 10.

[0050] In some embodiments, the thickness of a single refractive layer is 1 nm to 10 nm. When the thickness of a single refractive layer is within this range, the antireflective layer 102 that meets the refractive index requirements can be obtained more flexibly through the combination of multiple refractive layers, further improving the compatibility between the antireflective layer 102 and the substrate 101 and the first electrode layer 103. Optionally, the thickness of a single refractive layer can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any value within the range of any two of the above values. Furthermore, in their research on the design of an antireflective layer 102 with an equivalent refractive index through refractive layer stacking, the inventors discovered that when the refractive index difference between two adjacent refractive layers is large, and the thickness of a single refractive layer is much smaller than the wavelength of the incident light, the stacked refractive layers can make the equivalent refractive index of the antireflective layer 102 closer to the theoretical design value, which is beneficial to improving the accuracy of the refractive index design of the antireflective layer 102. For example, in the use of the solar cell 10, when the incident light is visible light, the wavelength of visible light is 400 nm to 800 nm. At this point, when the thickness of a single refractive layer is 1nm to 10nm, this thickness is much smaller than the wavelength of visible light, allowing for the design of an antireflective layer 102 with a more accurate equivalent refractive index. It is understandable that a single refractive layer can be prepared by methods such as evaporation, sputtering, or deposition.

[0051] In some embodiments, the number of refractive layers is 2 to 20. Within this range, the number of refractive layers allows for more flexible design of the equivalent refractive index of the antireflective layer 102, further improving the compatibility between the antireflective layer 102 and the substrate 101 and the first electrode layer 103. Optionally, the number of refractive layers can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc.

[0052] In some embodiments, the refractive index of the antireflection layer 102 is 1.32 to 3.28. By designing the antireflection layer 102, a layer with a wide range of refractive indices can be obtained, allowing the refractive index of the antireflection layer to better match the refractive indices of the substrate and the first electrode layer, reducing reflection of light when it enters the first electrode layer from the substrate, and further improving the light utilization efficiency of the solar cell. Optionally, the refractive index of the antireflection layer 102 can be 1.32, 1.51, 1.64, 1.73, 1.8, 1.92, 2.1, 2.24, 2.31, 2.44, 2.57, 2.61, 2.78, 2.94, 3.02, 3.14, 3.28, or any value within the range of any two of the above values.

[0053] In some embodiments, the thickness of the antireflection layer 102 is 50 nm to 200 nm. Light may experience some transmission loss when passing through the antireflection layer 102. A thickness within this range allows the antireflection layer 102 to have a better antireflection effect, while reducing light loss during transmission, further improving the light utilization efficiency of the solar cell 10. Furthermore, the thickness of the antireflection layer 102 is also related to the thickness of the solar cell 10. A thickness within this range allows the solar cell 10 to maintain a smaller thickness, which is beneficial for further improving the overall performance of the solar cell 10. Optionally, the thickness of the antireflection layer 102 can be 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, or any value within the range of any two of the above values.

[0054] In some embodiments, the refractive index of the substrate 101 is less than the refractive index of the first electrode layer 103. The antireflective layer 102 includes at least one first refractive layer 1021 and at least one second refractive layer 1022, wherein the refractive index of the first refractive layer 1021 is less than the refractive index of the second refractive layer 1022, and the first refractive layer 1021 and the second refractive layer 1022 are alternately stacked. The layer in the antireflective layer 102 closest to the substrate 101 is the first refractive layer 1021, and the layer in the antireflective layer 102 closest to the first electrode layer 103 is the second refractive layer 1022. The first refractive layer 1021 with a lower refractive index is close to the substrate 101 with a lower refractive index, and the second refractive layer 1022 with a higher refractive index is close to the first electrode layer 103 with a higher refractive index. At this time, the substrate 101 and the first refractive layer 1021 have good lattice matching, and the first electrode layer 103 and the second refractive layer 1022 have good lattice matching. This can improve the interlayer stability between the substrate 101, the antireflection layer 102 and the first electrode layer 103, reduce the risk of interlayer cracking in the solar cell 10, and improve the cycle stability of the solar cell 10.

[0055] In some embodiments, the difference between the refractive index of the second refractive layer 1022 and the refractive index of the first refractive layer 1021 is 0.5 to 1.9. Within this range, the difference in refractive index between the second refractive layer 1022 and the first refractive layer 1021 can be flexibly achieved by alternately stacking the second refractive layer 1022 and the first refractive layer 1021 to obtain an antireflection layer 102 adapted to the substrate 101 and the first electrode layer 103, ensuring that the equivalent refractive index of the antireflection layer 102 meets design requirements. Simultaneously, an antireflection layer 102 with a wide range of equivalent refractive indices can be obtained by fabricating the refractive layer using readily available materials. Optionally, the difference between the refractive index of the second refractive layer 1022 and the refractive index of the first refractive layer 1021 can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or any value within the range of any two of the above values.

[0056] In some embodiments, the refractive index of the first refractive layer 1021 is 1.32 to 1.65. For example, the refractive index of the first refractive layer 1021 can be 1.32, 1.38, 1.45, 1.51, 1.57, 1.62, 1.65 or any value within the range of any two of the above values.

[0057] Optionally, the material of the first refractive layer 1021 includes one or more of magnesium fluoride, silicon oxide, and aluminum oxide.

[0058] In some embodiments, the thickness of a single first refractive layer 1021 is 1 nm to 10 nm. Within this thickness range, the antireflective layer 102 that meets the refractive index requirements can be obtained more flexibly through the combination of multiple refractive layers, further improving the compatibility between the antireflective layer 102 and the substrate 101 and the first electrode layer 103. Optionally, the thickness of a single first refractive layer 1021 can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any two of the above values. It is understood that a single first refractive layer 1021 can be prepared by methods such as evaporation, sputtering, or deposition.

[0059] In some embodiments, the refractive index of the second refractive layer 1022 is 1.85 to 3.28. For example, the refractive index of the second refractive layer 1022 can be 1.85, 1.91, 2.13, 2.67, 2.85, 3.12, 3.28, or any value within the range of any two of the above values.

[0060] In some embodiments, the material of the second refractive layer 1022 includes one or more of zinc oxide, hafnium oxide, yttrium oxide, scandium oxide, lanthanum oxide, silicon nitride, tantalum oxide, zirconium oxide, germanium oxide, titanium oxide, niobium oxide, carbon nitride, zinc selenide, and barium titanate.

[0061] In some embodiments, the thickness of a single second refractive layer 1022 is 1 nm to 10 nm. Within this range, the thickness of the single second refractive layer 1022 can be used more flexibly with multiple refractive layers to obtain an antireflective layer 102 that meets the refractive index requirements, further improving the compatibility between the antireflective layer 102 and the substrate 101 and the first electrode layer 103. Optionally, the thickness of a single second refractive layer 1022 can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any value within the range of any two of the above values. It is understood that a single second refractive layer 1022 can be prepared by methods such as evaporation, sputtering, or deposition.

[0062] In some embodiments, substrate 101 includes a transparent substrate. A transparent substrate has better light transmittance, which is beneficial for further improving the light utilization efficiency of the solar cell 10. Optionally, substrate 101 includes a glass substrate and a flexible substrate. The material of the flexible substrate may be, but is not limited to, organic polymer materials. Further, the material of the flexible substrate 101 may be a mixture of one or more of the following materials in different proportions: including but not limited to polyvinyl alcohol (PVA), polyethylene terephthalate (PET), polyimide (PI), polyethylene dinaphthalate (PEN), polydimethylsiloxane (PDMS), etc.

[0063] In some embodiments, the surface of the substrate 101 near the first electrode layer 103 has a self-trapped light structure. By setting the self-trapped light structure, light reflection can be further reduced, improving the light utilization rate of the solar cell 10. It is understood that a self-trapped light structure refers to a surface structure composed of protrusions or depressions at the micrometer or nanometer scale. It can utilize phenomena such as light refraction, reflection, scattering, and interference to change the propagation path of light on the surface of the solar cell 10, reducing light reflection and thus improving light absorption. The self-trapped light structure can reduce the reflectivity of light at the incident surface of the solar cell 10, increasing light scattering and coupling, which is beneficial for improving the light utilization rate of the solar cell 10. It is understood that the self-trapped light structure can include pyramidal structures, inverted conical structures, moth-eye shaped structures, etc. Optionally, the self-trapped light structure can be prepared by laser processing or chemical processing.

[0064] In some embodiments, the first electrode layer 103 includes a transparent electrode layer. It is understood that the transparent electrode layer represents the electrode layer on the light-incident side of the solar cell 10. Optionally, the material of the first electrode layer 103 is selected from one or more of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), indium zinc oxide (IZO), and indium tungsten oxide (IWO). Optionally, the thickness of the first electrode layer 103 is 100 nm to 1000 nm. For example, the thickness of the first electrode layer 103 is 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, and any value within the range of any two of the above values. Further optionally, the thickness of the first electrode layer 103 is 300 nm to 800 nm.

[0065] In some embodiments, the material of the second electrode layer 105 includes at least one of a conductive metal, a conductive non-metal, and a conductive oxide. Optionally, the conductive metal is selected from at least one of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W, and their alloys. The conductive non-metal is selected from C. The conductive oxide includes at least one of indium tin oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), zinc aluminum oxide (AZO), boron-doped zinc oxide (BZO), and indium zinc oxide (IZO). Optionally, the thickness of the second electrode layer 105 is not particularly limited, and a commonly used electrode layer thickness in the art, such as 20 nm to 200 nm, can be used. For example, the thickness of the second electrode layer 105 is 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, or any value within the range of any two of the above values. Optionally, the thickness of the second electrode layer 105 is 60nm to 100nm, and more preferably, the thickness of the second electrode layer 105 is 70nm to 90nm. More preferably, the second electrode layer 105 is a back electrode layer.

[0066] In some embodiments, the light-absorbing layer 104 includes one or more of the following: a perovskite light-absorbing layer, a silicon-based light-absorbing layer, a cadmium telluride light-absorbing layer, a gallium arsenide light-absorbing layer, and a copper indium gallium selenide (CIGS) light-absorbing layer. By selecting the light-absorbing layer 104, different types of solar cells 10 can be obtained. For example, when the light-absorbing layer 104 includes a perovskite light-absorbing layer, a perovskite solar cell can be obtained. When the light-absorbing layer 104 is a silicon-based light-absorbing layer, a silicon-based solar cell can be obtained.

[0067] Optionally, the perovskite light-absorbing layer 104 comprises a material with the chemical formula ABX3 or A2CDX6. Wherein:

[0068] A is an inorganic, organic, or mixed organic-inorganic cation, comprising at least one of organic amine cations, Cs cations, K cations, Rb cations, and Li cations; the organic amine cation is selected from (NR1R2R3R4). + (R1R2N=CR3R4) + (R1R2N-C(R5)=NR3R4) + Or (R1R2N-C(NR5R6)=R3R4) + R1, R2, R3, R4, R5, and R6 are each independently selected from H, substituted or unsubstituted C1-20 alkyl groups, or substituted or unsubstituted aryl groups; A is optionally methylamino (CH3NH3) + (MA)+ ), formamidinyl (HC(NH2)2 + (FA) + ), cesium ions (Cs + ) and rubidium (Rb + At least one of the following, further optionally methylamino (CH3NH3) + ) or formamidinyl (HC(NH2)2 + ).

[0069] B is an inorganic, organic, or mixed organic-inorganic cation, including at least one of lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium, and optionally a divalent metal ion Pb. 2+ and Sn 2+ At least one of them.

[0070] C is an inorganic, organic, or mixed organic-inorganic cation, optionally a monovalent metal ion Ag. + wait.

[0071] D is an inorganic, organic, or organic-inorganic mixed cation, optionally a trivalent metal ion bismuth cation Bi. 3+ Antimony cation Sb 3+ Indium cations In 3+ wait.

[0072] X is an inorganic, organic, or organic-inorganic mixed anion, optionally one or more of a halide anion and a halide-like anion, and further optionally a bromide ion (Br). - ) or iodide ions (I - ).

[0073] In some embodiments, the thickness of the perovskite light-absorbing layer 104 is 100 nm to 1000 nm. Optionally, the thickness of the perovskite light-absorbing layer 104 can be, but is not limited to, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, and any value within the range of any two of the above values.

[0074] In some embodiments, the band gap of the perovskite absorbing layer 104 is 1.2 eV to 2.3 eV. As an example, the band gap of the perovskite absorbing layer 104 is 1.2 eV, 1.3 eV, 1.4 eV, 1.5 eV, 1.6 eV, 1.7 eV, 1.8 eV, 1.9 eV, 2 eV, 2.1 eV, 2.2 eV, 2.3 eV, or any value within the range of any two of the above values. When the band gap of the perovskite absorbing layer 104 is within the above range, it can have a higher visible light absorption efficiency.

[0075] In some embodiments, the solar cell 10 further includes one or more of a first charge extraction layer 106 and a second charge extraction layer 107; the first charge extraction layer 106 is located between the first electrode layer 103 and the light-absorbing layer 104, and the second charge extraction layer 107 is located between the second electrode layer 105 and the light-absorbing layer 104; one of the first charge extraction layer 106 and the second charge extraction layer 107 includes a hole transport layer and the other includes an electron transport layer.

[0076] It is understood that in the first charge extraction layer 106 and the second charge extraction layer 107, one includes a hole transport layer and the other includes an electron transport layer. Alternatively, one may include an electron transport layer and the other includes a hole transport layer. For example, in some embodiments, the first charge extraction layer 106 includes an electron transport layer and the second charge extraction layer 107 includes a hole transport layer. In other embodiments, the first charge extraction layer 106 includes a hole transport layer and the second charge extraction layer 107 includes an electron transport layer.

[0077] In some embodiments, the material of the electron transport layer may include, but is not limited to, one or more of the following materials and their derivatives: imide compounds, quinone compounds, fullerenes and their derivatives, methoxytriphenylamine-fluoroformamidinium (OMeTPA-FA), calcium titanate (CaTiO3), lithium fluoride (LiF), calcium fluoride (CaF2), poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS), poly3-hexylthiophene (P3HT), triphenylamine with a triphenylene core (H101), 3, 4-Ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-aniline)carbazole-spirobisfluorene (CzPAF-SBF), polythiophene, metal oxides, silicon dioxide (SiO2), strontium titanate (SrTiO3), cuprous thiocyanate (CuSCN), etc.; wherein the metal element may include one or more of Mg, Ni, Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr.

[0078] In some embodiments, the material of the hole transport layer may include, but is not limited to, one or more of the following materials and their derivatives: 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), nickel oxide (NiO2). x Materials such as poly(3,4-ethylenedioxythiophene), polystyrene sulfonate (PEDOT:PSS), and WO3 can transport holes and block electrons.

[0079] In some embodiments, the solar cell 10 further includes a metal fluoride layer. The metal fluoride layer is located between the electron transport layer and the first electrode layer 103. Alternatively, the metal fluoride layer is located between the electron transport layer and the second electrode layer 105. The presence of the metal fluoride layer can promote electron extraction, thereby improving the photoelectric conversion efficiency of the perovskite photovoltaic module.

[0080] It is understandable that other functional layers, such as modification layers, can be introduced into the solar cell 10 as needed. Optionally, the solar cell 10 can be provided with a modification layer of suitable energy level, which can play one or more of the following roles: lowering the energy level barrier, promoting energy level matching, improving charge extraction efficiency, passivating interface defect states, protecting the light-absorbing layer 104, suppressing the oxidation and decomposition of the cell by water molecules and oxygen, improving photoelectric conversion efficiency, and improving cell stability. Depending on the location of the modification layer, the type of modification layer may include a modification layer between the hole transport layer and the anode, a modification layer between the electron transport layer and the cathode, a modification layer between the hole transport layer and the light-absorbing layer 104, and a modification layer between the electron transport layer and the light-absorbing layer 104. Optionally, the materials that can be used for the modification layer in the perovskite solar cell 10 may include, but are not limited to, Cu2O, NiO, AZO, TiO2, etc.

[0081] It is understood that the solar cell 10 also includes an encapsulation layer 108. The encapsulation layer 108 is located on the surface of the second electrode layer 105 away from the light-absorbing layer 104. The encapsulation layer 108 provides better protection for the solar cell 10 and improves its stability. Optionally, the material of the encapsulation layer 108 includes an encapsulating adhesive. More preferably, the encapsulating adhesive includes one or more of epoxy encapsulating adhesives, silicone encapsulating adhesives, polyurethane encapsulating adhesives, UV-curable encapsulating adhesives, ethylene-vinyl acetate copolymers, polyvinyl butyral, ethylene octene copolymers, polyisobutylene, and polyolefin encapsulating adhesives.

[0082] Please refer to it again. Figure 1 In some embodiments, the solar cell 10 includes a substrate 101, a first refractive layer 1021, a second refractive layer 1022, a first electrode layer 103, a hole transport layer (i.e., a first charge extraction layer 106), a light-absorbing layer 104, an electron transport layer (i.e., a second charge extraction layer 107), a second electrode layer 105, and an encapsulation layer 108, which are stacked sequentially. The refractive index of the substrate 101 is less than that of the first electrode layer 103, and the refractive index of the first refractive layer 1021 is less than that of the second refractive layer 1022.

[0083] Understandably, in Figure 1In the context of multiple first refractive layers 1021 and multiple second refractive layers 1022, the ellipsis between the first refractive layer 1021 and the second refractive layer 1022 indicates the omission of the alternately stacked first refractive layer 1021 and the second refractive layer 1022.

[0084] Another embodiment of this application provides a photovoltaic system. The photovoltaic system includes the aforementioned solar cell 10.

[0085] Another embodiment of this application provides a power generation device. The power generation device includes the aforementioned solar cell 10.

[0086] Another embodiment of this application provides an electrical device. The electrical device includes the solar cell 10 described above.

[0087] In some embodiments, the aforementioned solar cells can be used as power generation devices for electrical devices. The type of power generation device may include, but is not limited to, integrated power generation. The location of the power generation device may include, but is not limited to, the roof of a vehicle, the back panel, etc.

[0088] Furthermore, the aforementioned electrical devices may include mobile devices, such as mobile phones and laptops, electric vehicles, electric trains, ships and satellites, power generation systems, etc., but are not limited to these.

[0089] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0090] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0091] Example 1

[0092] In this embodiment, the substrate is glass with a refractive index of 1.46, and the first electrode layer is FTO with a refractive index of 1.9.

[0093] The method for preparing the solar cell in this embodiment includes:

[0094] S101: Based on the refractive indices of the substrate and the first electrode layer, magnesium fluoride is selected as the material of the first refractive layer, and carbon nitride is selected as the material of the second refractive layer.

[0095] S102: Based on optical transmittance simulation, the thickness of the first refractive layer is calculated to be 6 nm, and the number of layers in the first refractive layer is 2. The thickness of the second refractive layer is 1 nm, and the number of layers in the second refractive layer is also 2. The equivalent refractive index of the antireflective layer is 1.74.

[0096] S103: An alternating layer of first and second refractive layers is fabricated on glass by magnetron sputtering to form an antireflective layer. The layer closest to the glass in the antireflective layer is the first refractive layer. The first refractive layer is made of magnesium fluoride, and the second refractive layer is made of carbon nitride. The thickness of the first refractive layer is 6 nm, and there are two first refractive layers. The thickness of the second refractive layer is 1 nm, and there are two second refractive layers.

[0097] S102: Fabricate a 100nm thick FTO transparent electrode on the antireflection layer.

[0098] S103: The FTO transparent electrode is treated with ultraviolet ozone, and then subjected to 1×10 -5 Under Torr conditions, nickel oxide with a thickness of 30 nm was magnetron sputtered and annealed at 200 °C for 30 min to obtain a hole transport layer.

[0099] S104: A 500nm thick perovskite film is coated on the surface of the hole transport layer. The film surface is continuously blown with an air knife for 30s, and then the film is transferred to a heating stage and annealed at 100℃ for 10min to form a perovskite layer.

[0100] S105: A 10 nm thick copper bath (BCP) is deposited on the perovskite layer to form an electron transport layer.

[0101] S106: A 100nm thick copper layer is deposited on the electron transport layer to form the second electrode. This yields a solar cell.

[0102] Comparative Example 1

[0103] In this comparative example, the substrate is glass with a refractive index of 1.46, and the first electrode layer is FTO with a refractive index of 1.9.

[0104] The method for preparing the solar cell in this comparative example includes:

[0105] S101: Fabricate a 100 nm thick FTO transparent electrode on a substrate.

[0106] S102: The FTO transparent electrode is treated with ultraviolet ozone, and then subjected to 1×10 -5 Under Torr conditions, nickel oxide with a thickness of 30 nm was magnetron sputtered and annealed at 200 °C for 30 min to obtain a hole transport layer.

[0107] S103: A 500nm thick perovskite film is coated on the surface of the hole transport layer. The film surface is continuously blown with an air knife for 30s, and then the film is transferred to a heating stage and annealed at 100℃ for 10min to form a perovskite layer.

[0108] S104: A 10 nm thick copper bath (BCP) is deposited on the perovskite layer to form an electron transport layer.

[0109] S105: A 100nm thick copper layer is deposited on the electron transport layer to form the second electrode. This yields a solar cell.

[0110] Test case

[0111] The light utilization efficiency of the solar cells obtained in the examples and comparative examples was tested. The test method involved using a solar simulator and an IV meter to measure the photoelectric conversion efficiency of the solar cells. The solar simulator conditions were: a total irradiance of 100 mW / cm². 2 The battery temperature was 25℃, and the spectral distribution was AM1.5G. The results are shown in Table 1.

[0112]

[0113] As can be seen from Table 1, the photoelectric conversion efficiency of the solar cell in Example 1 is significantly better than that in Comparative Example 1, indicating that the antireflection layer in Example 1 is beneficial to improving the light utilization rate of the solar cell and giving the solar cell a higher photoelectric conversion efficiency.

[0114] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A solar cell, characterized in that, The device includes a substrate, an antireflection layer, a first electrode layer, a light-absorbing layer, and a second electrode layer stacked along a first direction; the refractive index of the antireflection layer is between the refractive index of the substrate and the refractive index of the first electrode layer; the antireflection layer includes a plurality of refractive layers stacked along the first direction, wherein the refractive indices of two adjacent refractive layers are different.

2. The solar cell according to claim 1, characterized in that, The absolute value of the difference in refractive index between two adjacent refractive layers is 0.5 to 1.

9.

3. The solar cell according to claim 1 or 2, characterized in that, The absolute value of the difference in refractive index between two adjacent refractive layers is 1 to 1.

9.

4. The solar cell according to any one of claims 1 to 3, characterized in that, The refractive layer satisfies one or more of the following characteristics: (1) The material of the refractive layer includes one or more of magnesium fluoride, silicon oxide, aluminum oxide, zinc oxide, hafnium oxide, yttrium oxide, scandium oxide, lanthanum oxide, silicon nitride, tantalum oxide, zirconium oxide, germanium oxide, titanium oxide, niobium oxide, carbon nitride, zinc selenide, and barium titanate; (2) The thickness of a single refractive layer is 1 nm to 10 nm; (3) The number of the refractive layers is 2 to 20.

5. The solar cell according to any one of claims 1 to 4, characterized in that, The antireflection layer satisfies one or more of the following characteristics: (1) The refractive index of the antireflective layer is 1.32~3.28; (2) The thickness of the antireflection layer is 50nm~200nm.

6. The solar cell according to any one of claims 1 to 5, characterized in that, The refractive index of the substrate is less than that of the first electrode layer; the antireflection layer includes at least one first refractive layer and at least one second refractive layer, the refractive index of the first refractive layer is less than that of the second refractive layer, and the first refractive layer and the second refractive layer are alternately stacked; the layer closest to the substrate in the antireflection layer is the first refractive layer, and the layer closest to the first electrode layer in the antireflection layer is the second refractive layer.

7. The solar cell according to claim 6, characterized in that, The difference between the refractive index of the second refractive layer and the refractive index of the first refractive layer is 0.5 to 1.

9.

8. The solar cell according to claim 6 or 7, characterized in that, The first refractive layer satisfies one or more of the following characteristics: (1) The refractive index of the first refractive layer is 1.32~1.65; (2) The material of the first refractive layer includes one or more of magnesium fluoride, silicon oxide, and aluminum oxide; (3) The thickness of a single first refractive layer is 1 nm to 10 nm.

9. The solar cell according to any one of claims 6 to 8, characterized in that, The second refractive layer satisfies one or more of the following characteristics: (1) The refractive index of the second refractive layer is 1.85~3.28; (2) The material of the second refractive layer includes one or more of zinc oxide, hafnium oxide, yttrium oxide, scandium oxide, lanthanum oxide, silicon nitride, tantalum oxide, zirconium oxide, germanium oxide, titanium oxide, niobium oxide, carbon nitride, zinc selenide, and barium titanate; (3) The thickness of a single second refractive layer is 1 nm to 10 nm.

10. The solar cell according to any one of claims 1 to 9, characterized in that, The basis satisfies one or more of the following characteristics: (1) The substrate includes a transparent substrate; (2) The surface of the substrate near the first electrode layer has a self-trapping light structure.

11. The solar cell according to any one of claims 1 to 10, characterized in that, The light-absorbing layer includes one or more of the following: perovskite light-absorbing layer, silicon-based light-absorbing layer, cadmium telluride light-absorbing layer, gallium arsenide light-absorbing layer, and copper indium gallium selenide light-absorbing layer.

12. The solar cell according to any one of claims 1 to 11, characterized in that, The solar cell further includes one or more of a first charge extraction layer and a second charge extraction layer; the first charge extraction layer is located between the first electrode layer and the light-absorbing layer, and the second charge extraction layer is located between the second electrode layer and the light-absorbing layer; In the first charge extraction layer and the second charge extraction layer, one includes a hole transport layer and the other includes an electron transport layer.

13. A photovoltaic system, characterized in that, The solar cell includes any one of claims 1 to 12.

14. A power generation device, characterized in that, The solar cell includes any one of claims 1 to 12.

15. An electrical appliance, characterized in that, The solar cell includes any one of claims 1 to 12.

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