Solar cell structure, solar cell and photovoltaic module

Abstract

The invention relates to a solar cell structure, a solar cell and a photovoltaic module. The solar cell structure comprises a substrate; a first reflection structure, wherein the first reflection structure is grown on the substrate; the energy conversion layer is grown on the first reflection structure; and the second reflection structure grows on the energy conversion layer, and the second reflection structure is used for transmitting light incident from one side opposite to the energy conversion layer and reflecting light incident from one side of the first reflection structure. By adopting the method, the second reflection structure can reflect back the light reflected by the first reflection structure and emitted to the second reflection structure, and the light returns to the energy conversion layer again, so that multiple reflection of the light between the first reflection structure and the second reflection structure is realized, and the utilization rate of sunlight by the cell is greatly increased; therefore, the photoelectric conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a solar cell structure, a solar cell, and a photovoltaic module. Background Technology

[0002] Gallium arsenide (GaAs) solar cells have seen sustained development in recent years. However, due to their high cost, GaAs solar cells are currently only widely used in aerospace equipment such as spacecraft and satellites, and they still cannot occupy a major position in commercial applications.

[0003] In related technologies, several pairs of distributed Bragg reflectors (DBRs) can be grown at the bottom of GaAs solar cells to increase the reflection of incident sunlight, allowing sunlight to be reused in the solar cells. However, the reflected sunlight is prone to leaking out of the solar cells and cannot be effectively utilized. Summary of the Invention

[0004] Therefore, it is necessary to provide a solar cell structure to address the problem that reflected sunlight easily leaks out of the solar cell and cannot be effectively utilized.

[0005] Firstly, this application provides a solar cell structure, including:

[0006] Substrate;

[0007] A first reflective structure, wherein the first reflective structure is grown on a substrate;

[0008] An energy conversion layer is grown on the first reflective structure;

[0009] A second reflective structure is grown on the energy conversion layer. The second reflective structure is used to transmit light incident from the side opposite to the energy conversion layer and reflect light incident from the side of the first reflective structure.

[0010] In one embodiment, the second reflective structure consists of several pairs of double-layer structures, each pair including a first layer and a second layer, wherein the refractive index of the material of the first layer and the refractive index of the material of the second layer are different.

[0011] In one embodiment, the refractive index of the material of the first layer is less than that of the material of the second layer.

[0012] In one embodiment, the thickness of the first layer of the top double-layer structure, which is away from the energy conversion layer, is λ1 / 4, and the thickness of the second layer of the top double-layer structure, which is away from the energy conversion layer, is λ1 / 2.

[0013] The thickness of the first layer of the bottom double-layer structure adjacent to the energy conversion layer is λ1 / 4, and the thickness of the second layer of the bottom double-layer structure adjacent to the energy conversion layer is λ1 / 2.

[0014] The thickness of the first and second layers of the remaining intermediate double-layer structure is λ1 / 2, where λ1 is the center wavelength of the incident light.

[0015] In one embodiment, the first layer is made of aluminum gallium indium phosphide, and the second layer is made of gallium indium phosphide.

[0016] In one embodiment, the energy conversion layer includes a first energy conversion sublayer adjacent to the second reflective structure and a second energy conversion sublayer adjacent to the first reflective structure;

[0017] The first energy conversion sublayer is made of gallium indium arsenide, and the second energy conversion sublayer is made of gallium indium phosphorus.

[0018] In one embodiment, the refractive index of the material of the first energy conversion sublayer is greater than the refractive index of the material of the second layer structure and the refractive index of the material of the second energy conversion sublayer.

[0019] In one embodiment, the first reflective structure includes a third layer and a fourth layer, which are stacked alternately in sequence. The refractive index of the material of the third layer is different from that of the material of the fourth layer. The thickness of the third layer and the thickness of the fourth layer are both λ2 / 4, where λ2 is the center wavelength of the target reflection wavelength.

[0020] Secondly, this application also provides a solar cell, including the solar cell structure of any of the above.

[0021] Thirdly, this disclosure also provides a photovoltaic module. It includes: a housing, and the solar cell structure described above;

[0022] The solar cell structure is disposed within the housing.

[0023] The aforementioned solar cell structure has at least the following beneficial effects:

[0024] In the embodiments provided in this disclosure, sunlight entering the energy conversion layer is ideally absorbed and converted into electrical energy. However, in reality, some light leaks out from the top of the energy conversion layer, resulting in energy loss. The second reflective structure can reflect the light that has been reflected by the first reflective structure back to the second reflective structure, returning it to the energy conversion layer. This allows the light to be reflected multiple times between the first and second reflective structures, enabling it to be absorbed again in the energy conversion layer and reused. This significantly increases the utilization rate of sunlight by the battery, thereby improving the photoelectric conversion efficiency of the solar cell.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments or conventional technologies of this disclosure, the accompanying drawings used in the description of the embodiments or conventional technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the solar cell structure in one embodiment;

[0028] Figure 2 This is a schematic diagram of the solar cell structure in one embodiment;

[0029] Figure 3 This is a schematic diagram of the solar cell structure in one embodiment;

[0030] Figure 4 This is a schematic diagram of a solar cell structure in one embodiment. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings.

[0032] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims. The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitation, the presence of other identical or equivalent elements in a process, method, product, or apparatus that includes said elements is not excluded. For example, the use of terms such as "first," "second," etc., is to denote names and does not indicate any specific order.

[0033] This disclosure provides a solar cell structure. Figure 1 This is a schematic diagram of a solar cell structure in one embodiment, including: a substrate 1, a first reflective structure 2 grown on the substrate 1, an energy conversion layer 3 grown on the first reflective structure 2, and a second reflective structure 4 grown on the energy conversion layer 3.

[0034] In one embodiment of this disclosure, GaAs (gallium arsenide) can be used as substrate 1. GaAs is a direct bandgap semiconductor with a high light absorption coefficient, allowing photons to directly excite electron-hole pairs, achieving efficient photoelectric conversion without complex structures. Compared to traditional Si solar cells, GaAs as a substrate material exhibits superior electron mobility, optical properties, temperature stability, and radiation resistance.

[0035] In one embodiment of this disclosure, Figure 2This is a schematic diagram of a solar cell structure in one embodiment. The first reflective structure 2 includes a third layer 21 and a fourth layer 22, which are stacked alternately. The refractive indices of the materials in the third layer 21 and the fourth layer 22 are different. The greater the difference in refractive indices between the materials in the third layer 21 and the fourth layer 22, the higher the reflectivity for the same number of layers. The first reflective structure 2 can be a distributed Bragg reflector (DBR). The material of the third layer 21 can be gallium arsenide (GaAs), and the material of the fourth layer 22 can be aluminum gallium arsenide (AlGaAs). The refractive index of AlGaAs is approximately 3.0, and the refractive index of GaAs is approximately 3.5. The refractive index difference between the two is approximately 0.5, making it easier to achieve high reflectivity.

[0036] The thickness of the third layer 21 and the fourth layer 22 is λ² / 4, where λ² is the center wavelength of the target reflection wavelength. The target reflection wavelength can refer to the specific wavelength expected to achieve high reflectivity when designing the first reflection structure. For example, if the first reflection structure 2 is designed to have high reflectivity in the 800-900 nm band, then λ² = 850 nm is the center wavelength of this band. When light is reflected at adjacent interfaces, the λ / 4 thickness design ensures a 180° phase difference between the reflected light, resulting in constructive interference after superposition. The number of layers in the third layer 21 and the fourth layer 22 can be adjusted according to requirements. The first reflection structure 2 can be used to reflect light that has not been absorbed by the energy conversion layer 3, allowing the light to propagate repeatedly inside the solar cell and increasing the number of light absorption cycles.

[0037] In one embodiment of this disclosure, Figure 3 This is a schematic diagram of a solar cell structure in one embodiment. The energy conversion layer 3 includes a first energy conversion sub-layer 31 adjacent to the second reflective structure 4 and a second energy conversion sub-layer 32 adjacent to the first reflective structure 2. The first energy conversion sub-layer 31 is made of gallium indium arsenide (GaInP), and the second energy conversion sub-layer 32 is made of gallium indium phosphide (GaInAs). The main wavelength range of sunlight is 300-700 nm and 700-1800 nm. The 300-700 nm wavelength range accounts for 43% of sunlight, and GaInP can absorb 35%-40% of it. The 700-1800 nm wavelength range accounts for 53% of sunlight, and GaInAs captures 45-50% of it. GaInP is used to absorb high-energy short wavelengths, and GaInAs is used to absorb low-energy long wavelengths. The combination of the two can cover more than 85% of the energy of sunlight. Two different energy conversion sublayers correspond to different wavelengths of sunlight, achieving broadband absorption. Unabsorbed light passes through the energy conversion layer and reaches the first reflection structure for reflection. The energy conversion layer can then perform secondary absorption of the unabsorbed light.

[0038] In one embodiment of this disclosure, Figure 4 This is a schematic diagram of a solar cell structure in one embodiment. The second reflective structure 4 consists of several pairs of double-layer structures. Each pair of double-layer structures includes a first layer and a second layer. The refractive index of the material of the first layer is different from that of the second layer. Specifically, the refractive index of the material of the first layer is less than that of the material of the second layer.

[0039] The thickness of the first layer 41 of the top double-layer structure, which is far from the energy conversion layer 3, is 1λ / 4, and the thickness of the second layer 42 of the top double-layer structure, which is far from the energy conversion layer, is 1λ / 2.

[0040] The thickness of the first layer 43 of the bottom double-layer structure adjacent to the energy conversion layer 3 is 1λ / 4, and the thickness of the second layer 44 of the bottom double-layer structure adjacent to the energy conversion layer 3 is 1λ / 2.

[0041] The thickness of the first and second layers of the remaining double-layer structure is 1λ / 2, where 1λ is the center wavelength of the incident light. The center wavelength refers to the center wavelength of the incident light band targeted by the product.

[0042] First, when the incident light enters the second reflective structure 4 from the air, the refractive index of the material of the first layer 41 of the top double-layer structure is greater than that of air, that is, from an optically less dense medium to an optically denser medium. When the light is reflected on the upper surface of the first layer 41 of the top double-layer structure, a half-wave loss occurs, resulting in a phase change of π. When the light is reflected on the lower surface of the first layer 41 of the top double-layer structure, the refractive index of the material of the first layer is less than that of the material of the second layer. From an optically less dense medium to an optically denser medium, a half-wave loss occurs, resulting in a phase change of π. The thickness of the first layer 41 of the top double-layer structure is λ1 / 4, the optical path difference is 2×(λ1 / 4)=λ1 / 2, and the phase change is π. Therefore, the total phase changes of the reflected light from the upper surface and the reflected light from the lower surface of the first layer 41 of the top double-layer structure are π and 2π, respectively, and the two reflected beams interfere and cancel each other out.

[0043] When light is reflected from the upper surface of the second layer 42 of the top-layer double-layer structure, the refractive index of the material of the first layer 41 is less than that of the material of the second layer 42. This results in a half-wave loss and a phase change of π due to the change from a less dense medium to a denser medium. When light is reflected from the lower surface of the second layer 42 of the top-layer double-layer structure, the change occurs from a denser medium to a less dense medium. The thickness of the second layer 42 of the top-layer double-layer structure is λ1 / 2, and the optical path difference is 2×(λ1 / 2)=λ1, resulting in a phase change of 2π. Therefore, the total phase changes of the reflected light from the upper surface and the lower surface of the second layer 42 of the top-layer double-layer structure are π and 2π, respectively, and the two reflected beams interfere with each other destructively.

[0044] Secondly, the thickness of the first and second layers of the remaining intermediate double-layer structure is λ1 / 2. In one embodiment of this disclosure, the remaining intermediate double-layer structure includes a first structural layer 45 and a second structural layer 46. When light is reflected from the upper surface of the first structural layer 45 of the intermediate double-layer structure, the phase does not change from an optically denser medium to an optically less dense medium. When light is reflected from the lower surface of the first structural layer 45 of the intermediate double-layer structure, the phase changes from an optically less dense medium to an optically denser medium, resulting in a half-wave loss and a phase change of π. Since the thickness of the first structural layer 45 of the intermediate double-layer structure is λ1 / 2, the optical path difference is 2×(λ1 / 2)=λ1, and the phase change is 2π. Therefore, the total phase changes of the reflected light from the upper surface of the first structural layer 45 of the intermediate double-layer structure and the reflected light from the lower surface of the first structural layer 45 of the intermediate double-layer structure are 0 and 3π, respectively, and the two reflected beams interfere destructively.

[0045] When light is reflected from the upper surface of the second layer 46 of the intermediate double-layer structure, it undergoes a half-wave loss due to the change from a less dense medium to a denser medium, resulting in a phase change of π. When light is reflected from the lower surface of the second layer 46 of the intermediate double-layer structure, it undergoes a change from a denser medium to a less dense medium, resulting in no phase change. The thickness of the second layer 46 of the intermediate double-layer structure is λ1 / 2, and the optical path difference is 2×(λ1 / 2)=λ1, resulting in a phase change of 2π. Therefore, the total phase changes of the reflected light from the upper surface of the second layer 46 of the intermediate double-layer structure and the reflected light from the lower surface of the second layer 46 of the intermediate double-layer structure are π and 2π, respectively, and the two reflected beams interfere with each other destructively.

[0046] Finally, when light is reflected from the upper surface of the first layer 43 of the bottom double-layer structure, the phase does not change as it travels from a denser medium to a less dense medium. When light is reflected from the lower surface of the first layer 43 of the bottom double-layer structure, a half-wave loss occurs as it travels from a less dense medium to a denser medium, resulting in a phase change of π. The thickness of the first layer 43 of the bottom double-layer structure is λ1 / 4, and the optical path difference is 2×(λ1 / 4)=λ1 / 2, resulting in a phase change of π. Therefore, the total phase changes of the reflected light from the upper surface of the first layer 43 of the bottom double-layer structure and the reflected light from the lower surface of the first layer 43 of the bottom double-layer structure are 0 and 2π, respectively, and the two reflected beams undergo constructive interference.

[0047] When light is reflected from the upper surface of the second layer 44 of the bottom double-layer structure, a half-wave loss occurs as the light travels from a less dense medium to a denser medium, resulting in a phase change of π. When light is reflected from the lower surface of the second layer 44 of the bottom double-layer structure, a half-wave loss occurs as the light travels from a less dense medium to a denser medium, resulting in a phase change of π. The thickness of the second layer 44 of the bottom double-layer structure is λ1 / 2, the optical path difference is 2×(λ1 / 2)=λ1, and the phase change is 2π. Therefore, the total phase changes of the reflected light from the upper surface of the second layer 44 of the bottom double-layer structure and the reflected light from the lower surface of the second layer 44 of the bottom double-layer structure are π and 3π, respectively, and the two reflected beams undergo constructive interference.

[0048] Therefore, the second reflective structure 4 reduces the intensity of reflected light, thus achieving an anti-reflection effect. Adding the second reflective structure 4 to the top of the solar cell enhances the transmission of sunlight incident from the top, increasing the efficiency of sunlight entering the solar cell.

[0049] First, in the embodiments of this disclosure, when light propagates upwards to the interface between the GaInP solar cell layer and the second reflective structure 4 after being reflected by the first reflective structure 2, the refractive index of GaInP is higher than that of the second layer 44 of the bottom double-layer structure. When light is reflected from the lower surface of the second layer 44 of the bottom double-layer structure, there is no half-wave loss from the optically denser medium to the optically less dense medium, and the phase difference is 0. When light is reflected from the upper surface of the second layer 44 of the bottom double-layer structure, the refractive index of the second layer 44 of the bottom double-layer structure is greater than that of the first layer 43 of the bottom double-layer structure. There is no half-wave loss from the optically denser medium to the optically less dense medium, and the phase difference is 0. The thickness of the second layer 44 of the bottom double-layer structure is λ1 / 2, the optical path difference is 2×(λ1 / 2)=λ, and the phase change is 2π. Therefore, the total phase changes of the reflected light from the lower surface of the second layer 44 of the bottom double-layer structure and the reflected light from the upper surface of the second layer 44 of the bottom double-layer structure are 0 and 2π, respectively, resulting in constructive phase interference.

[0050] When light is reflected from the lower surface of the first layer 43 of the bottom double-layer structure, there is no half-wave loss from the optically denser medium to the optically less dense medium, and the phase difference is 0. When light is reflected from the upper surface of the first layer 43 of the bottom double-layer structure, there is a half-wave loss from the optically less dense medium to the optically denser medium, and the phase difference is π. The thickness of the first layer 43 of the bottom double-layer structure is λ1 / 4, the optical path difference is 2×(λ1 / 4)=λ1 / 2, and the phase change is π. Therefore, the total phase changes of the reflected light from the lower surface of the first layer 43 of the bottom double-layer structure and the reflected light from the upper surface of the first layer 43 of the bottom double-layer structure are 0 and 2π, respectively, resulting in constructive phase interference.

[0051] Secondly, when light is reflected from the lower surface of the second layer 46 of the intermediate double-layer structure, it undergoes a half-wave loss from a less dense medium to a denser medium, resulting in a phase change of π. When light is reflected from the upper surface of the second layer 46 of the intermediate double-layer structure, it undergoes a phase change from a denser medium to a less dense medium. The thickness of the second layer 46 of the intermediate double-layer structure is λ1 / 2, the optical path difference is 2×(λ1 / 2)=λ1, and the phase change is 2π. Therefore, the total phase changes of the reflected light from the upper surface of the second layer 46 of the intermediate double-layer structure and the reflected light from the lower surface of the second layer 46 of the intermediate double-layer structure are π and 2π, respectively, and the two reflected beams interfere with each other destructively.

[0052] When light is reflected from the lower surface of the first structural layer 45 of the intermediate double-layer structure, the phase does not change as it travels from a denser medium to a less dense medium. When light is reflected from the upper surface of the first structural layer 45 of the intermediate double-layer structure, a half-wave loss occurs as it travels from a less dense medium to a denser medium, resulting in a phase change of π. The thickness of the first structural layer 45 of the intermediate double-layer structure is λ1 / 2, and the optical path difference is 2×(λ1 / 2)=λ1, resulting in a phase change of 2π. Therefore, the total phase changes of the reflected light from the upper surface of the first structural layer 45 of the intermediate double-layer structure and the reflected light from the lower surface of the first structural layer 45 of the intermediate double-layer structure are 0 and 3π, respectively, and the two reflected beams interfere destructively.

[0053] Finally, when light is reflected from the lower surface of the second layer 42 of the top double-layer structure, it changes from an optically less dense medium to an optically denser medium, resulting in a half-wave loss and a phase change of π. When light is reflected from the upper surface of the second layer 42 of the top double-layer structure, it changes from an optically denser medium to an optically less dense medium. The thickness of the second layer 42 of the top double-layer structure is λ1 / 2, the optical path difference is 2×(λ1 / 2)=λ1, and the phase change is 2π. The two reflected beams interfere and cancel each other out.

[0054] When light is reflected from the lower surface of the first layer 41 of the top double-layer structure, the phase change is 0 from the optically denser medium to the optically less dense medium; when light is reflected from the upper surface of the first layer 41 of the top double-layer structure, the phase change is 0 from the optically denser medium to the optically less dense medium. The thickness of the first layer 41 of the top double-layer structure is 1λ / 4, the optical path difference is 2×(λ1 / 4)=λ1 / 2, and the phase change is π. Therefore, the total phase changes of the reflected light from the upper surface and the reflected light from the lower surface of the first layer 41 of the top double-layer structure are 0 and π, respectively, and the two reflected beams interfere with each other destructively.

[0055] Therefore, the second reflective structure 4 allows sunlight to be reused in the energy conversion layer 3, limiting light leakage from the top.

[0056] Ideally, sunlight entering the energy conversion layer 3 would be absorbed and converted into electrical energy. However, in reality, some light leaks out from the top of the energy conversion layer 3, resulting in energy loss. The second reflective structure 4 can reflect the light that has been reflected by the first reflective structure 2 back to the energy conversion layer 3, allowing the light to be reflected multiple times between the first reflective structure 2 and the second reflective structure 4. The light can then be absorbed again in the energy conversion layer 3, achieving reuse and greatly increasing the utilization rate of sunlight by the battery, thereby improving the photoelectric conversion efficiency of the solar cell.

[0057] In one embodiment of this disclosure, the first layer is made of aluminum gallium indium phosphide, and the second layer is made of gallium indium phosphide.

[0058] Both AlGaInP and GaInP are wide bandgap semiconductors (typically >1.8 eV), with corresponding light absorption threshold wavelengths that are relatively short (<690 nm). In the energy conversion layer of a solar cell, the first energy conversion sublayer 31 (GaInAs, bandgap ≈1.3 eV) mainly absorbs long-wavelength light in the 700-1800 nm range, while the second energy conversion sublayer 32 (GaInP, bandgap ≈1.8 eV) mainly absorbs short-wavelength light in the 300-670 nm range.

[0059] Since the band gaps of AlGaInP and GaInP are larger than those of the energy conversion layer, they have lower absorption rates for the 300-1800 nm wavelength range of light that the energy conversion layer needs to absorb. Therefore, they do not block the effective light, ensuring that the incident light can penetrate the second reflection structure and reach the energy conversion layer efficiently for absorption.

[0060] In one embodiment of this disclosure, a solar cell includes the solar cell structure described above.

[0061] In one embodiment of this disclosure, a photovoltaic module includes a housing and a solar cell structure of any of the above; the solar cell structure is disposed within the housing.

[0062] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0063] 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.

[0064] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent disclosure. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the appended claims.

Claims

1. A solar cell structure, characterized in that, include: Substrate; A first reflective structure, wherein the first reflective structure is grown on a substrate; An energy conversion layer is grown on the first reflective structure; A second reflective structure is grown on the energy conversion layer. The second reflective structure is used to transmit light incident from the side opposite to the energy conversion layer and reflect light incident from the side of the first reflective structure.

2. The solar cell structure according to claim 1, characterized in that, The second reflective structure consists of several pairs of double-layer structures. Each pair of double-layer structures includes a first layer structure and a second layer structure. The refractive index of the material of the first layer structure is different from that of the material of the second layer structure.

3. The solar cell structure according to claim 2, characterized in that, The refractive index of the material in the first layer is less than that of the material in the second layer.

4. The solar cell structure according to claim 3, characterized in that, The thickness of the first layer of the top double-layer structure, which is far from the energy conversion layer, is λ1 / 4, and the thickness of the second layer of the top double-layer structure, which is far from the energy conversion layer, is λ1 / 2. The thickness of the first layer of the bottom double-layer structure adjacent to the energy conversion layer is λ1 / 4, and the thickness of the second layer of the bottom double-layer structure adjacent to the energy conversion layer is λ1 / 2. The thickness of the first and second layers of the remaining intermediate double-layer structure is λ1 / 2, where λ1 is the center wavelength of the incident light.

5. The solar cell structure according to claim 4, characterized in that, The first layer is made of aluminum gallium indium phosphide, and the second layer is made of gallium indium phosphide.

6. The solar cell structure according to claim 5, characterized in that, The energy conversion layer includes a first energy conversion sub-layer adjacent to the second reflective structure and a second energy conversion sub-layer adjacent to the first reflective structure; The first energy conversion sublayer is made of gallium indium arsenide, and the second energy conversion sublayer is made of gallium indium phosphorus.

7. The solar cell structure according to claim 6, characterized in that, The refractive index of the material of the first energy conversion sublayer is greater than the refractive index of the material of the second layer structure and the refractive index of the material of the second energy conversion sublayer.

8. The solar cell structure according to claim 1, characterized in that, The first reflective structure includes a third layer and a fourth layer, which are stacked alternately in sequence. The refractive index of the material of the third layer is different from that of the material of the fourth layer. The thickness of the third layer and the thickness of the fourth layer are both λ2 / 4, where λ2 is the center wavelength of the target reflection wavelength.

9. A solar cell, characterized in that, Includes the solar cell structure according to any one of claims 1-8.

10. A photovoltaic module, characterized in that, include: The housing, and the solar cell structure as described in any one of claims 1-9; The solar cell structure is disposed within the housing.

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