Two-sided differentiated textured structure for monocrystal silicon heterojunction solar cells and preparation method thereof

Abstract

The invention relates to a two-sided differentiated textured structure for monocrystal silicon heterojunction solar cells, which is characterized in that the light receiving side and the shady side ofa silicon wafer side structure are of different structures, the light receiving side is a pyramidal textured structure, and the shady side is a polished side or a pyramidal textured structure largerthan the light receiving side. A chain cleaning machine is used for texturing in the whole process, and the shady side is etched by wet chemical etching after groove texturing, so that the pyramidal textured structure is enlarged or polished. Then, RCA cleaning, HF natural oxidation layer removing, slow lifting and drying are carried out. The textured structures of the light receiving side and theshady side are designed separately based on the different light entry characteristics of the two sides, and the problem on how to produce and manufacture a differentiated textured structure is solved. A simplified process which can reduce the subsequent production cost and take into account the composite loss of the back surface and the short circuit current is provided.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to a double-sided differentiated suede structure for a monocrystalline silicon heterojunction solar cell and a preparation method thereof. Background technique [0002] Monocrystalline silicon heterojunction solar cells have high conversion efficiency and are recognized by the photovoltaic industry as one of the key technologies for the next generation of large-scale industrialization. One of the great advantages of monocrystalline silicon heterojunction solar cells is that their double-sided power generation characteristics are very good, and it is an ideal double-sided solar cell. In practical applications, the light entering characteristics of the two surfaces of the solar cell are different: as the main light-receiving surface, its light entering characteristics are mainly direct light, which can be expressed by the standard solar spectrum, and its strongest light intensity is concent...

AI Technical Summary

Problems solved by technology

However, the monocrystalline silicon heterojunction solar cell is designed according to the standard solar spectrum on both sides of the structure, which makes it unable to achieve the optimal state in the actual environment when it is used as a double-sided solar cell.

Another reason for this situation is that during the preparation process of this type of solar cell, the cleaning and texturing step adopts a groove-type texturing cleaning method, which forms the same texturing structure on both sides of the silicon wafer. , it is impossible to form a differentiated structure, and of course, the subsequent CVD and PVD preparation processes have to match it, and it is impossible to achieve the optimal film structure configuration of double-sided solar cells.

[0003] In addition to the above-mentioned anti-reflection effect on incident light that cannot be optimally designed, the high specific surface area of ​​the backlight surface will also cause the problem of high surface recombination rate, which will reduce the open circuit voltage of the heterojunction solar cell; Will cause more TCO and amorphous silicon materials to be consumed, and increase process time

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