TOPCon solar cell structure
By designing a multi-layer tunneling structure and specific oxide layer in TOPCon solar cells, the problem of rapid degradation of performance under ultraviolet irradiation is solved, and higher UV resistance and UV attenuation resistance is achieved, meeting customers' high efficiency requirements, while maintaining production economy and efficiency.
Patent Information
- Application Number
- CN202510183567.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-19
- Publication Date
- 2025-05-16
AI Technical Summary
TOPCon solar cells are prone to rapid deterioration under ultraviolet irradiation, resulting in a decrease in power output, especially more fragile than traditional aluminum back-side field batteries.
A TOPCon solar cell structure is designed, including an N-type silicon substrate, an upper superimposed film layer structure and a lower superimposed film layer structure, and the ultraviolet resistance of the battery is enhanced through a multi-layer tunneling structure and a specific oxide layer.
It effectively increases the UV resistance of the battery cell, improves the components' resistance to UV attenuation, reduces the value of ultraviolet induced attenuation (UVID), meets customers' attenuation requirements after UV60KW, and takes into account both production costs and production capacity.
Smart Images
Figure CN120018636A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of solar cells, and in particular to a TOPCon solar cell structure. Background Art
[0002] The effects of UV radiation on interfacial defects and damage mechanisms in solar cells, especially in high-efficiency silicon-based solar cells, have attracted extensive attention. The structure of TOPCon solar cells relies on an ultrathin oxide layer formed on the surface of the silicon wafer, which acts as a passivation layer and reduces surface recombination losses. Studies by Sinha et al. and Ye et al. have both found that all types of silicon-based solar cells have some degree of device performance degradation after exposure to UV radiation. The main reason for the performance degradation of solar cells irradiated with UV light is due to the significant decrease in open circuit voltage and fill factor. The photon energy of UV light is comparable to the energy of Si-H bonds, and hydrogen complex bonds play a vital role in the performance of a-Si:H films, indicating that UV exposure can significantly affect bonding. This phenomenon can induce recombination of charge carriers at the interface, thereby reducing the efficiency of the cell. UV radiation causes the chemical bonds in the material to break down and form new chemical species. The generation of these species can cause significant losses in photocurrent. Pinochet et al. found that after 4200 hours of accelerated UV aging, the photocurrent loss of some modules reached 4%.
[0003] The performance degradation of TOPCon solar cells under UV irradiation is mainly manifested in the decrease of power output. This degradation shows different sensitivities in different types of cells, especially compared with traditional aluminum back surface field (Al-BSF) cells, TOPCon cells and other high-efficiency cells (such as SHJ and PERC cells) are more vulnerable. In TOPCon cells exposed to UV radiation, new defects may be generated between the oxide layer and the silicon substrate, resulting in reduced carrier transfer efficiency. This interface damage may lead to short-term and long-term performance degradation of the cell. Due to the sensitivity of TOPCon cells to UV light, it becomes crucial to use appropriate materials and coating technologies for the cells.
[0004] Therefore, the applicant has developed a TOPCon solar cell structure to solve the above problems. Summary of the invention
[0005] The present invention provides a TOPCon solar cell structure to solve the problem that the performance of the existing TOPCon solar cell is prone to rapid degradation under ultraviolet irradiation.
[0006] The present invention achieves the above-mentioned purpose through the following technical solutions: The present invention provides a TOPCon solar cell structure, comprising: N-type silicon substrate; An upper stacked film layer structure, wherein the upper stacked film layer structure is arranged on the upper surface of the N-type silicon substrate, and the upper stacked film layer structure comprises a P-Si layer, a first silicon oxide layer, a first aluminum oxide layer, a second aluminum oxide layer, a second silicon oxide layer, a third silicon oxide layer, a first silicon oxynitride layer, a second silicon oxynitride layer, a third silicon oxynitride layer, a first silicon nitride layer, a second silicon nitride layer, a third silicon nitride layer, a fourth silicon nitride layer, a fourth silicon oxynitride layer, a fifth silicon oxynitride layer, a sixth silicon oxynitride layer, a fourth silicon oxide layer, and a fifth silicon oxide layer, which are stacked in sequence from bottom to top; A lower stacked film layer structure, wherein the lower stacked film layer structure is disposed on the lower surface of the N-type silicon substrate, and the lower stacked film layer structure is a multi-layer tunneling structure; The electrode structure includes an electrode arranged on the upper surface of the upper stacked film layer structure and an electrode arranged on the lower surface of the lower stacked film layer structure.
[0007] Further, the thickness of the first silicon oxide layer is 0.5-1.5nm, the thickness of the first aluminum oxide layer is 0.1-5nm, the thickness of the second aluminum oxide layer is 0.1-5nm, the thickness of the second silicon oxide layer is 0.1-10nm, the thickness of the third silicon oxide layer is 0.1-10nm, the thickness of the first silicon oxynitride layer is 0.1-10nm, the thickness of the second silicon oxynitride layer is 0.1-10nm, the thickness of the third silicon oxynitride layer is 0.1-10nm, the thickness of the first silicon nitride layer is The thickness of the second silicon nitride layer is 0.1-20nm, the thickness of the third silicon nitride layer is 0.1-20nm, the thickness of the fourth silicon nitride layer is 0.1-20nm, the thickness of the fourth silicon oxynitride layer is 0.1-10nm, the thickness of the fifth silicon oxynitride layer is 0.1-10nm, the thickness of the sixth silicon oxynitride layer is 0.1-10nm, the thickness of the fourth silicon oxide layer is 0.1-10nm, and the thickness of the fifth silicon oxide layer is 0.1-10nm.
[0008] Furthermore, the multilayer tunneling structure includes a single silicon oxide layer, a first doped polysilicon thin film layer, a multilayer silicon oxide layer, and a multilayer second doped polysilicon thin film layer arranged in sequence from top to bottom, and the multilayer second doped polysilicon thin film layer includes a multilayer stacked second doped polysilicon thin film layer.
[0009] Furthermore, the multi-layer silicon oxide layer includes 1-15 layers of silicon oxide layers, and the multi-layer second doped polysilicon thin film layer includes 1-15 layers of stacked second doped polysilicon thin film layers.
[0010] Furthermore, the thicknesses of the single silicon oxide layer, the first doped polysilicon thin film layer, the multi-layer silicon oxide layer, and the multi-layer second doped polysilicon thin film layer are 0.5-2.5 nm, 1-150 nm, 0.5-2.5 nm, and 1-150 nm, respectively.
[0011] Furthermore, the doping concentration of the first doped polysilicon thin film layer is 10^19 atoms per cubic centimeter, and the doping concentration of the single layer of the second doped polysilicon thin film layer is 10^21 atoms per cubic centimeter. The first doped polysilicon thin film layer and the second doped polysilicon thin film layer are both doped with phosphorus.
[0012] Furthermore, each layer structure of the stacked film layer structure is sequentially deposited and connected by PECVD equipment.
[0013] Furthermore, the electrodes are all silver electrodes.
[0014] The beneficial effects of the present invention are: A TOPCon solar cell structure proposed in the present invention can effectively increase the UV resistance of the cell and improve the ability of the module to resist UV attenuation. At the same time, it takes into account the possibility of mass production and is designed from an industrial perspective. It can be fully matched with the current mass production TOPCon cell production line equipment and process technology without the need for additional equipment. It also takes into account production costs and production capacity. The structural design will not increase the burden on production costs and will not affect production capacity. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a schematic diagram of the structure of the TOPCon solar cell in this application.
[0016] In the figure: P-si layer-1; first silicon oxide layer-2; first aluminum oxide layer-3; second aluminum oxide layer-4; second silicon oxide layer-5; third silicon oxide layer-6; first silicon nitride oxide layer-7; second silicon nitride oxide layer-8; third silicon nitride oxide layer-9; first silicon nitride layer-10; second silicon nitride layer-11; third silicon nitride layer-12; fourth silicon nitride layer-13; fourth silicon nitride oxide layer-14; fifth silicon nitride oxide layer-15; sixth silicon nitride oxide layer-16; fourth silicon oxide layer-17; fifth silicon oxide layer-18; single-layer silicon oxide layer-19; first doped polysilicon thin film layer-20; multi-layer silicon oxide layer-21; multi-layer second doped polysilicon thin film layer-22. DETAILED DESCRIPTION
[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.
[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0019] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0020] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.
[0021] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.
[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The term "UVID" in this application means ultraviolet induced attenuation.
[0023] The first doped polysilicon thin film layer (i.e. Figure 1The poly-N+ in the polysilicon material specifically refers to: the polysilicon thin film layer formed by high-concentration N-type doping on the surface of the polysilicon material, which changes from the intrinsic state to an N-type semiconductor. The doping substance is phosphorus (P), and the doping concentration is 10^19 atoms per cubic centimeter; "Multi-layer second doped polysilicon thin film layer" (i.e. Figure 1 The poly-N++ in it specifically refers to: the surface layer of the polycrystalline silicon material is formed by ultra-high concentration N-type doping, and the polycrystalline silicon thin film layer is changed from the intrinsic state to an N-type semiconductor. The doping substance is phosphorus (P), and the doping concentration is 10^21 atoms per cubic centimeter.
[0024] The first doped polysilicon thin film layer and the multiple layers of second doped polysilicon thin film layers are prepared by adopting the existing doped polysilicon thin film preparation process.
[0025] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.
[0026] like Figure 1 As shown, a TOPCon solar cell structure includes: The present invention provides a TOPCon solar cell structure, comprising: N-type silicon substrate (i.e. Figure 1 N-Si in ); An upper stacked film layer structure, wherein the upper stacked film layer structure is arranged on the upper surface of the N-type silicon substrate, and the upper stacked film layer structure comprises a P-Si layer 1, a first silicon oxide layer 2, a first aluminum oxide layer 3, a second aluminum oxide layer 4, a second silicon oxide layer 5, a third silicon oxide layer 6, a first silicon oxynitride layer 7, a second silicon oxynitride layer 8, a third silicon oxynitride layer 9, a first silicon nitride layer 10, a second silicon nitride layer 11, a third silicon nitride layer 12, a fourth silicon nitride layer 13, a fourth silicon nitride layer 14, a fifth silicon nitride layer 15, a sixth silicon nitride layer 16, a fourth silicon oxide layer 17, and a fifth silicon oxide layer 18, which are stacked in sequence from bottom to top; A lower stacked film layer structure, wherein the lower stacked film layer structure is disposed on the lower surface of the N-type silicon substrate, and the lower stacked film layer structure is a multi-layer tunneling structure; The electrode structure includes an electrode arranged on the upper surface of the upper stacked film layer structure and an electrode arranged on the lower surface of the lower stacked film layer structure.
[0027] In some embodiments, the thickness of the first silicon oxide layer is 0.5-1.5 nm, the thickness of the first aluminum oxide layer is 0.1-5 nm, the thickness of the second aluminum oxide layer is 0.1-5 nm, the thickness of the second silicon oxide layer is 0.1-10 nm, the thickness of the third silicon oxide layer is 0.1-10 nm, the thickness of the first silicon oxynitride layer is 0.1-10 nm, the thickness of the second silicon oxynitride layer is 0.1-10 nm, the thickness of the third silicon oxynitride layer is 0.1-10 nm, the thickness of the first silicon nitride layer is The thickness of the layer is 0.1-20nm, the thickness of the second silicon nitride layer is 0.1-20nm, the thickness of the third silicon nitride layer is 0.1-20nm, the thickness of the fourth silicon nitride layer is 0.1-20nm, the thickness of the fourth silicon oxynitride layer is 0.1-10nm, the thickness of the fifth silicon oxynitride layer is 0.1-10nm, the thickness of the sixth silicon oxynitride layer is 0.1-10nm, the thickness of the fourth silicon oxide layer is 0.1-10nm, and the thickness of the fifth silicon oxide layer is 0.1-10nm.
[0028] Among them, the first layer of P-Si on the upper surface is prepared by boron diffusion and oxidation process, and can be achieved by high-temperature thermal diffusion through two states of impurity sources BCl3 and BBr3, and superimposed dry oxygen and wet oxygen processes and dry / wet oxygen alternating oxidation processes. The first layer of silicon oxide is generated by natural oxidation, the first layer of aluminum oxide is made by ALD equipment, the second layer of oxidation is prepared by ALD equipment, the second layer of silicon oxide is prepared by PECVD, the third layer of silicon oxide is prepared by PECVD, the first layer of silicon oxynitride is prepared by PECVD, the second layer of silicon oxynitride is prepared by PECVD, the third layer of silicon oxynitride is prepared by PECVD, the first layer of silicon nitride is prepared by PECVD, the second layer of silicon nitride is prepared by PECVD, the third layer of silicon nitride is prepared by PECVD, the fourth layer of silicon nitride is prepared by PECVD, the fourth layer of silicon oxynitride is prepared by PECVD, the fifth layer of silicon oxynitride is prepared by PECVD, the sixth layer of silicon oxynitride is prepared by PECVD, the fourth layer of silicon oxide is prepared by PECVD, and the fifth layer of silicon oxide is prepared by PECVD.
[0029] This structural design is based on N-type silicon wafers, with superimposed film layers on the upper and lower surfaces. The lower surface is mainly multi-layer tunneling structure technology. This structure can be achieved using PE-Poly technology route, LP-Poly technology route and PVD-Poly technology route.
[0030] like Figure 1As shown, in some embodiments, the multi-layer tunneling structure includes a single-layer silicon oxide layer 19, a first doped polysilicon thin film layer 20, a multi-layer silicon oxide layer 21, and a multi-layer second doped polysilicon thin film layer 22 arranged in sequence from top to bottom, and the multi-layer second doped polysilicon thin film layer includes a multi-layer stacked second doped polysilicon thin film layer.
[0031] In some embodiments, the multi-layer silicon oxide layer includes 1-15 layers of silicon oxide layers, and the multi-layer second doped polysilicon thin film layer includes 1-15 stacked second doped polysilicon thin film layers.
[0032] In some embodiments, the thicknesses of the single silicon oxide layer, the first doped polysilicon thin film layer, the multi-layer silicon oxide layer, and the multi-layer second doped polysilicon thin film layer are 0.5-2.5 nm, 1-150 nm, 0.5-2.5 nm, and 1-150 nm, respectively.
[0033] In some embodiments, the doping concentration of the first doped polysilicon thin film layer is 10^19 atoms per cubic centimeter, and the doping concentration of the single layer of the second doped polysilicon thin film layer is 10^21 atoms per cubic centimeter. The first doped polysilicon thin film layer and the second doped polysilicon thin film layer are both doped with phosphorus, and the atoms are doped atoms.
[0034] In some embodiments, each layer structure of the stacked film layer structure is sequentially deposited and connected by PECVD equipment.
[0035] In some embodiments, the electrodes are silver electrodes.
[0036] The existing mass production technology TOPCon battery UVID value is relatively large, and the attenuation after UV60KW is greater than 2%, which cannot meet the needs of component-end customers. At present, customers in the industry generally require UV60KW to be less than 1.5%. In the future, as efficiency continues to improve and technology continues to be added, higher UVID requirements will be proposed. At present, some leading customers have required UV60KW≤1%. This requirement poses severe technical tests and challenges to battery cell manufacturers. The above customer requirements can be met through the present invention.
[0037] This paper aims to solve the UVID problem of TOPCon battery assemblies in traditional technologies, and designs a new battery structure that can effectively increase the UV resistance of battery cells and improve the ability of components to resist UV attenuation. The battery structure designed by the present invention has been repeatedly verified many times, and can effectively reduce UVID to less than 1%, which not only meets the requirements of existing customers, but also the requirements of future customers. The battery structure of the present invention is significantly different from the conventional TOPCon battery structure. The attenuation value of the battery with this structure is significantly lower than that of the conventional TOPCon battery after UV60kW, which innovatively reduces the UVID at the manufacturing end of the battery cell. At the same time, the possibility of mass production has been deeply considered at the beginning of the design of this structure. It is designed from the perspective of industrialization and can be fully matched with the current mass production TOPCon battery production line equipment and process technology without the need for additional equipment; it also takes into account production costs and production capacity. This structural design will not increase the burden on production costs and will not affect production capacity.
[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A TOPCon solar cell structure, characterized in that: include: N-type silicon substrate; An upper stacked film layer structure, wherein the upper stacked film layer structure is arranged on the upper surface of the N-type silicon substrate, and the upper stacked film layer structure comprises a P-Si layer, a first silicon oxide layer, a first aluminum oxide layer, a second aluminum oxide layer, a second silicon oxide layer, a third silicon oxide layer, a first silicon oxynitride layer, a second silicon oxynitride layer, a third silicon oxynitride layer, a first silicon nitride layer, a second silicon nitride layer, a third silicon nitride layer, a fourth silicon nitride layer, a fourth silicon oxynitride layer, a fifth silicon oxynitride layer, a sixth silicon oxynitride layer, a fourth silicon oxide layer, and a fifth silicon oxide layer, which are stacked in sequence from bottom to top; A lower stacked film layer structure, wherein the lower stacked film layer structure is disposed on the lower surface of the N-type silicon substrate, and the lower stacked film layer structure is a multi-layer tunneling structure; The electrode structure includes an electrode arranged on the upper surface of the upper stacked film layer structure and an electrode arranged on the lower surface of the lower stacked film layer structure.
2. A TOPCon solar cell structure according to claim 1, characterized in that: The thickness of the first silicon oxide layer is 0.5-1.5 nm, the thickness of the first aluminum oxide layer is 0.1-5 nm, the thickness of the second aluminum oxide layer is 0.1-5 nm, the thickness of the second silicon oxide layer is 0.1-10 nm, the thickness of the third silicon oxide layer is 0.1-10 nm, the thickness of the first silicon oxynitride layer is 0.1-10 nm, the thickness of the second silicon oxynitride layer is 0.1-10 nm, the thickness of the third silicon oxynitride layer is 0.1-10 nm, the thickness of the first silicon nitride layer is The thickness of the second silicon nitride layer is 0.1-20nm, the thickness of the third silicon nitride layer is 0.1-20nm, the thickness of the fourth silicon nitride layer is 0.1-20nm, the thickness of the fourth silicon oxynitride layer is 0.1-10nm, the thickness of the fifth silicon oxynitride layer is 0.1-10nm, the thickness of the sixth silicon oxynitride layer is 0.1-10nm, the thickness of the fourth silicon oxide layer is 0.1-10nm, and the thickness of the fifth silicon oxide layer is 0.1-10nm.
3. A TOPCon solar cell structure according to claim 1, characterized in that: The multilayer tunneling structure includes a single silicon oxide layer, a first doped polysilicon thin film layer, a multilayer silicon oxide layer, and a multilayer second doped polysilicon thin film layer arranged in sequence from top to bottom, and the multilayer second doped polysilicon thin film layer includes a multilayer stacked second doped polysilicon thin film layer.
4. A TOPCon solar cell structure according to claim 3, characterized in that: The multi-layer silicon oxide layer includes 1-15 layers of silicon oxide layers, and the multi-layer second doped polysilicon thin film layer includes 1-15 layers of stacked second doped polysilicon thin film layers.
5. A TOPCon solar cell structure according to claim 3, characterized in that: The thicknesses of the single-layer silicon oxide layer, the first doped polysilicon thin film layer, the multi-layer silicon oxide layer, and the multi-layer second doped polysilicon thin film layer are 0.5-2.5nm, 1-150nm, 0.5-2.5nm, and 1-150nm, respectively.
6. A TOPCon solar cell structure according to claim 5, characterized in that: The doping concentration of the first doped polysilicon thin film layer is 10^19 atoms per cubic centimeter, and the doping concentration of the single layer of the second doped polysilicon thin film layer is 10^21 atoms per cubic centimeter. The first doped polysilicon thin film layer and the second doped polysilicon thin film layer are both doped with phosphorus.
7. A TOPCon solar cell structure according to claim 1, characterized in that: The layers of the stacked film structure are deposited and connected in sequence through PECVD equipment.
8. A TOPCon solar cell structure according to claim 1, characterized in that: The electrodes are all silver electrodes.