Four-end laminated solar cell

Abstract

The utility model provides a four-end laminated solar cell. The four-end laminated solar cell comprises a cell assembly, a crystalline silicon cell assembly and an antireflection layer assembly, the crystalline silicon battery assembly and the battery assembly are connected through the antireflection layer assembly; the anti-reflection layer assembly comprises a plurality of anti-reflection layers which are laminated in sequence; the crystalline silicon battery assembly comprises a crystalline silicon lower electrode, a P-type non / microcrystalline silicon layer, a first amorphous silicon layer, a silicon substrate, a second amorphous silicon layer, an N-type non / microcrystalline silicon layer and a crystalline silicon upper electrode which are arranged in sequence. According to the technical scheme, reflection of light at the interface can be reduced through the design of the multi-layer antireflection layer structure, the light incidence amount is increased, light propagation and distribution are improved, and the photoelectric conversion efficiency is improved; the multi-layer antireflection layer structure can adjust the refractive index change at the interface, respectively increase the transmittance of photons in the short wave direction and photons in the long wave direction, and improve the output power of the four-end laminated assembly. The multi-layer antireflection layer can also increase density so as to protect the battery assembly from being eroded by water vapor molecules.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a four-terminal stacked solar cell. Background Art

[0002] As a renewable energy source, solar energy is an important way to solve the current energy crisis and environmental pollution. The research and development of efficient and low-cost solar cells has received extensive attention. Perovskite cells have received more and more attention and research due to their simple preparation process, low cost, and the ability to prepare large-area flexible and transparent cells.

[0003] By adjusting the band gap of perovskite, cells with different band gap widths are stacked from top to bottom according to the size of the band gap width to form a stacked device with all perovskites at both ends, which can broaden the absorption spectrum range of the cell and improve the photoelectric conversion efficiency of solar cells. The energy distribution in the solar energy spectrum is relatively wide. Although the stacked cells at both ends of the series connection can overcome some existing problems to a certain extent, the stacked cells at both ends of the series connection need to meet the characteristics of current matching, which is limited by the minimum current of its single cell, and the daily changes in the solar energy spectrum will cause current mismatch and reduce efficiency.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Utility Model Content

[0005] The embodiments of the present application provide a four-terminal stacked solar cell to solve or alleviate one or more of the technical problems mentioned above.

[0006] As one aspect of an embodiment of the present application, the embodiment of the present application provides a four-terminal stacked solar cell, comprising: a cell assembly, a crystalline silicon cell assembly and an anti-reflection layer assembly; the crystalline silicon cell assembly and the cell assembly are connected via the anti-reflection layer assembly;

[0007] The anti-reflection layer assembly comprises a plurality of anti-reflection layers stacked in sequence;

[0008] The crystalline silicon cell assembly comprises a crystalline silicon lower electrode, a P-type non- / microcrystalline silicon layer, a first amorphous silicon layer, a silicon substrate, a second amorphous silicon layer, an N-type non- / microcrystalline silicon layer and a crystalline silicon upper electrode which are arranged in sequence.

[0009] Optionally, the anti-reflection layer assembly includes a first anti-reflection layer group and a second anti-reflection layer group, the first anti-reflection layer group includes a plurality of first sub-anti-reflection layers, and the second anti-reflection layer group includes a plurality of second sub-anti-reflection layers; the anti-reflection layer assembly also includes a connecting layer, the connecting layer is located between the first anti-reflection layer group and the second anti-reflection layer group, and is used to connect the first anti-reflection layer group and the second anti-reflection layer group.

[0010] Optionally, the connecting layer is made of thermoplastic polyolefin.

[0011] Optionally, the first sub-anti-reflection layer and the second sub-anti-reflection layer are prepared from materials independently selected from one of magnesium fluoride, lithium fluoride, silicon nitride and silicon oxide.

[0012] Optionally, the battery component is one of a perovskite battery, a CIGS battery, a CdTe battery, a Sb2S3 battery and a Sb2Se3 battery.

[0013] Optionally, the battery assembly includes a perovskite lower electrode, an electron transport layer, a perovskite active layer, a hole transport layer and a perovskite upper electrode arranged in sequence.

[0014] Optionally, there are multiple battery assemblies, and the multiple battery assemblies are independently arranged.

[0015] Optionally, the bandgap of the battery component is greater than 1.3 eV.

[0016] Optionally, the bandgap width of the crystalline silicon battery assembly is 1.12 eV.

[0017] Optionally, in the anti-reflection layer, the middle anti-reflection layer is n medium , the adjacent anti-reflection layer is n top , the next adjacent anti-reflection layer is n bottom ;

[0018] Among them, n medium 、n top and n bottom The refractive index satisfies the following formula;

[0019]

[0020] The above technical solution adopted in the embodiment of the present application may have the following advantages:

[0021] An anti-reflection layer assembly is arranged between the battery assembly and the crystalline silicon battery assembly. The design of the multi-layer anti-reflection layer structure can reduce the reflection of light at the interface, increase the incident amount of light, and improve the propagation and distribution of light, thereby improving the photoelectric conversion efficiency; in addition, the multi-layer anti-reflection layer structure can effectively adjust the refractive index change at the interface, increase the transmittance of short-wave photons and long-wave photons respectively, and improve the output power of the four-terminal stacked assembly; at the same time, the multi-layer anti-reflection layer can also increase the density to protect the battery assembly from being corroded by water vapor molecules. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0023] Figure 1 It is a schematic diagram of the structure of a four-terminal stacked solar cell provided in an embodiment of the present application.

[0024] Description of reference numerals:

[0025] 1. Battery assembly; 11. Perovskite lower electrode; 12. Electron transport layer; 13. Perovskite active layer; 14. Hole transport layer; 15. Perovskite upper electrode; 2. Crystalline silicon battery assembly; 31. First anti-reflection layer group; 311. First sub-anti-reflection layer; 32. Second anti-reflection layer group; 321. Second sub-anti-reflection layer; 33. Connecting layer. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other in the absence of conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0029] like Figure 1 As shown, the four-terminal stacked solar cell includes a cell assembly 1, a crystalline silicon cell assembly 2 and an anti-reflection layer assembly, wherein the anti-reflection layer assembly is located between the cell assembly 1 and the crystalline silicon cell assembly 2.

[0030] The crystalline silicon cell assembly 2 includes a crystalline silicon lower electrode, a P-type non- / microcrystalline silicon layer, a first amorphous silicon layer, a silicon substrate, a second amorphous silicon layer, an N-type non- / microcrystalline silicon layer and a crystalline silicon upper electrode arranged in sequence; the anti-reflection layer assembly includes a plurality of anti-reflection layers stacked in sequence. In the embodiment of the present application, the cell assembly 1 and the crystalline silicon cell assembly 2 are connected together through a plurality of anti-reflection layers stacked in sequence to form a four-terminal stacked solar cell, and the four-terminal stacked solar cell can lead out two positive and negative electrodes, that is, it has four wiring terminals. In addition, the cell assembly 1 and the crystalline silicon cell assembly 2 in the four-terminal stacked solar cell have independent circuit connections, and can maintain a large power output under various working conditions. It should be noted that, theoretically, when the number of anti-reflection layers is large, the performance of the four-terminal stacked solar cell is greatly improved. Each additional anti-reflection layer will reduce the reflection of a part of the light, thereby increasing the light absorption and the performance of the cell. More multi-layer anti-reflection layers may help reduce reflection within a specific wavelength range, thereby improving the performance of the solar cell, especially under multi-spectral conditions. Therefore, in the embodiment of the present application, the number of anti-reflection layers used is a total of 20 layers.

[0031] Among the anti-reflection layers stacked in sequence, the middle anti-reflection layer is n medium , the adjacent anti-reflection layer is n top , the next adjacent anti-reflection layer is n bottom ; where n medium 、n top and n bottom The refractive index satisfies the following formula;

[0032] The refractive index of the anti-reflection layer needs to match the refractive index of the material in the cell to reduce reflection. In addition, by adjusting the refractive index of the anti-reflection layer, the transmittance of light on the cell surface can be maximized, thereby increasing the amount of light absorbed. Therefore, when the three adjacent anti-reflection layers meet the above formula, the reflection of light on the interface can be minimized, thereby increasing the light absorption and conversion efficiency of the four-terminal stacked solar cell.

[0033] In this embodiment, an anti-reflection layer assembly is arranged between the battery assembly 1 and the crystalline silicon battery assembly 2. The design of the multi-layer anti-reflection layer structure can reduce the reflection of light at the interface, increase the incident amount of light, and improve the propagation and distribution of light, thereby improving the photoelectric conversion efficiency; in addition, the multi-layer anti-reflection layer structure can effectively adjust the refractive index change at the interface, increase the transmittance of short-wave photons and long-wave photons respectively, and improve the output power of the four-terminal stacked assembly; at the same time, the multi-layer anti-reflection layer can also increase the density to protect the battery assembly 1 from being corroded by water vapor molecules.

[0034] In an optional embodiment, the anti-reflection layer assembly includes a first anti-reflection layer group 31 and a second anti-reflection layer group 32; the anti-reflection layer assembly also includes a connecting layer 33, the number of the connecting layer 33 can be only one, the connecting layer 33 is located between the first anti-reflection layer group 31 and the second anti-reflection layer group 32, and is used to connect the first anti-reflection layer group 31 and the second anti-reflection layer group 32; wherein the first anti-reflection layer group 31 is located between the battery assembly 1 and the connecting layer 33, and is used to connect the battery assembly 1 and the connecting layer 33. The second anti-reflection layer group 32 is located between the connecting layer 33 and the crystalline silicon battery assembly 2, and is used to connect the crystalline silicon battery assembly 2 and the connecting layer 33. The first anti-reflection layer group 31 includes a plurality of first sub-anti-reflection layers 311, and the second anti-reflection layer group 32 includes a plurality of second sub-anti-reflection layers 321. It should be noted that the number of the first sub-anti-reflection layers 311 and the second sub-anti-reflection layers 321 is not limited. In the embodiment of the present application, the number of the first sub-anti-reflection layers 311 and the second sub-anti-reflection layers 321 is the same, and is 10 layers respectively.

[0035] In an optional embodiment, the connecting layer 33 is made of thermoplastic polyolefin. Thermoplastic polyolefin is a thermoplastic elastomer material, usually composed of polyolefin polymers such as polypropylene (PP) and polyethylene (PE) and additives such as rubber. Thermoplastic polyolefin has good softness and elasticity, and has good performance, and also has good waterproof performance and thermal adhesion. Therefore, the first anti-reflection layer group 31 and the second anti-reflection layer group 32 can be well bonded together, and at the same time have a certain sealing performance to reduce the erosion of water.

[0036] In an optional embodiment, the preparation material of the first sub-anti-reflection layer 311 and the second sub-anti-reflection layer 321 is one of magnesium fluoride, lithium fluoride, silicon nitride and silicon oxide. The preparation material of the first sub-anti-reflection layer 311 and the second sub-anti-reflection layer 321 selected in the embodiment of the present application is magnesium fluoride, which has high optical transparency and can allow light to penetrate the anti-reflection layer with high efficiency. After the surface of magnesium fluoride is properly treated, it can effectively reduce the reflection of light, thereby improving the photoelectric conversion efficiency of the solar cell. In addition, magnesium fluoride has good chemical stability and can withstand a certain degree of corrosion, thereby extending the service life of the anti-reflection layer.

[0037] In an optional embodiment, the battery assembly 1 is one of a perovskite cell, a CIGS cell, a CdTe cell, a Sb2S3 cell and a Sb2Se3 cell. Among them, perovskite cells, CIGS cells, CdTe cells, Sb2S3 cells and Sb2Se3 cells are all different types of thin-film solar cells, which convert solar photons into electrical energy by using different materials and processes. CIGS cells have high efficiency and low cost, and perform well in low light intensity environments. CdTe cells have relatively low production costs and have high photoelectric conversion efficiency and good stability. Sb2S3 cells are an emerging solar cell, however, their efficiency and stability are relatively low. Sb2Se3 cells have a higher absorption coefficient and better photoelectric properties. Perovskite cells have better photoelectric conversion efficiency, wider spectrum absorption, low production cost and material diversity compared to other solar cells. Therefore, in the embodiment of the present application, the preferred battery assembly 1 is a perovskite battery to form a perovskite / crystalline silicon laminated solar cell structure. Theoretically, a four-terminal laminated solar cell composed of a perovskite battery and a crystalline silicon battery assembly 2 can achieve a photoelectric conversion efficiency of more than 30%. The battery assembly 1 includes a perovskite lower electrode 11, an electron transport layer 12, a perovskite active layer 13, a hole transport layer 14 and a perovskite upper electrode 15 arranged in sequence. The perovskite lower electrode 11 is located on the first sub-anti-reflection layer 311, and then the electron transport layer 12 is prepared on the perovskite lower electrode 11 by scraping, spraying and other methods, and then the perovskite active layer 13 and the hole transport layer 14 are prepared in sequence on the electron transport layer 12 by the same method, and finally a transparent silver electrode is used as the perovskite upper electrode 15 to complete the preparation of the perovskite battery assembly 1 structure.

[0038] In an optional embodiment, there are multiple battery assemblies 1, and the multiple battery assemblies 1 are independently arranged. In the embodiment of the present application, the battery assembly 1 used is a perovskite battery assembly 1, and the number of the perovskite battery assembly 1 is two.

[0039] In this embodiment, two perovskite cells can be optimized for a specific spectral range to maximize the absorption of solar photon energy and convert it into electrical energy. The design of multiple perovskite cell components 1 enables different perovskite materials to be optimized for absorbing solar spectra of different bands, so that the components can use light energy more efficiently; and when each perovskite cell is designed to be the most suitable band for its absorption and conversion, the photoelectric conversion efficiency of the overall component is improved; in addition, since multiple perovskite cells can compensate each other to provide more stable output power, the impact of single cell efficiency changes is reduced; in addition, by combining perovskite cells of different bands, it is possible to adapt to solar energy absorption under different lighting conditions, thereby improving the performance of the components in different environments.

[0040] In an optional embodiment, the bandgap width of the battery component 1 is greater than 1.3 eV, and the bandgap width of the crystalline silicon battery component 2 is 1.12 eV.

[0041] In this embodiment, the larger bandgap width makes the perovskite cell material have a wider absorption range for light and can absorb more solar photons. In order to ensure that the perovskite cell has sufficient light absorption capacity and photoelectric conversion efficiency, as the bandgap width increases, the perovskite cell has a higher absorption efficiency for light of different wavelengths, so it can convert light energy into electrical energy in a wider spectral range. When the bandgap width of the perovskite cell is greater than 1.3eV, it can absorb photons with a wavelength less than 950nm, and light with a longer wavelength can penetrate in and be absorbed by the silicon cell with a narrow bandgap of 1.12eV, which can absorb photons with a wavelength less than 1100nm. When the two form a stacked cell, the absorption spectra of the two complement each other, which makes it possible to maximize the conversion of light energy into electrical energy, improve the utilization rate of the solar energy spectrum, the performance and stability of the cell, and reduce the preparation cost.

[0042] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0043] For the convenience of description, the orientation or position relationship indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, vertical, horizontal" and "top, bottom" is usually based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. Unless otherwise stated, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0044] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] Unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.

[0046] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0047] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0048] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0049] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A four-terminal stacked solar cell, characterized in that: include: A battery assembly (1), a crystalline silicon battery assembly (2) and an anti-reflection layer assembly; the crystalline silicon battery assembly (2) and the battery assembly (1) are connected via the anti-reflection layer assembly; The anti-reflection layer assembly comprises a plurality of anti-reflection layers stacked in sequence; The crystalline silicon cell assembly (2) comprises a crystalline silicon lower electrode, a P-type non- / microcrystalline silicon layer, a first amorphous silicon layer, a silicon substrate, a second amorphous silicon layer, an N-type non- / microcrystalline silicon layer and a crystalline silicon upper electrode which are arranged in sequence.

2. The four-terminal stacked solar cell according to claim 1, characterized in that: The anti-reflection layer assembly comprises a first anti-reflection layer group (31) and a second anti-reflection layer group (32), wherein the first anti-reflection layer group (31) comprises a plurality of first sub-anti-reflection layers (311), and the second anti-reflection layer group (32) comprises a plurality of second sub-anti-reflection layers (321); the anti-reflection layer assembly further comprises a connecting layer (33), wherein the connecting layer (33) is located between the first anti-reflection layer group (31) and the second anti-reflection layer group (32), and is used for connecting the first anti-reflection layer group (31) and the second anti-reflection layer group (32).

3. The four-terminal stacked solar cell according to claim 2, characterized in that: The connecting layer (33) is made of thermoplastic polyolefin.

4. The four-terminal stacked solar cell according to claim 2, characterized in that: The first sub-anti-reflection layer (311) and the second sub-anti-reflection layer (321) are prepared from materials independently selected from one of magnesium fluoride, lithium fluoride, silicon nitride and silicon oxide.

5. The four-terminal tandem solar cell according to any one of claims 1 to 4, characterized in that: The battery component (1) is one of a perovskite battery, a CIGS battery, a CdTe battery, a Sb2S3 battery and a Sb2Se3 battery.

6. The four-terminal tandem solar cell according to any one of claims 1 to 4, characterized in that: The battery assembly (1) comprises a perovskite lower electrode (11), an electron transport layer (12), a perovskite active layer (13), a hole transport layer (14) and a perovskite upper electrode (15) which are arranged in sequence.

7. The four-terminal tandem solar cell according to any one of claims 1 to 4, characterized in that: The number of the battery components (1) is multiple, and the multiple battery components (1) are independently arranged.

8. The four-terminal tandem solar cell according to any one of claims 1 to 4, characterized in that: The forbidden band width of the battery component (1) is greater than 1.3 eV.

9. The four-terminal tandem solar cell according to any one of claims 1 to 4, characterized in that: The bandgap width of the crystalline silicon battery component (2) is 1.12 eV.

10. The four-terminal tandem solar cell according to any one of claims 1 to 4, characterized in that: In the anti-reflection layer, the middle anti-reflection layer is n medium , the adjacent anti-reflection layer is n top , the next adjacent anti-reflection layer is n bottom ; Among them, n medium 、n top and n bottom The refractive index satisfies the following formula;

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