Heterojunction solar cell and preparation method thereof

Abstract

The invention relates to the field of solar cells. The invention discloses a heterojunction solar cell. The heterojunction solar cell comprises a substrate, a first intrinsic amorphous layer, a second intrinsic amorphous layer, a first doping layer, a second doping layer, a first transparent conducting layer, a second transparent conducting layer and a laminated structure, wherein the laminated structure comprises a first metal nitride film layer, a metal film layer and a second metal nitride film layer which are laminated in sequence; and the laminated structure is arranged on the transparent conducting layer. The invention also discloses a preparation method of the heterojunction solar cell. According to the heterojunction solar cell and the preparation method thereof, the contact resistance of the electrode on the back face of the cell can be reduced, and the fill factor of the cell is promoted; and moreover, the back face has an extremely good reflection function, and more light can be absorbed by the substrate, so that a thinner substrate can be used, the substrate material is saved, and the cost is reduced.

Description

technical field [0001] The invention belongs to the field of solar cells, and in particular relates to a heterojunction solar cell and a preparation method thereof. Background technique [0002] Solar cells can directly convert sunlight into electricity, so as a new energy source, more and more countries are paying attention. [0003] Heterojunction with Intrinsic Thin layer solar cell, referred to as HIT solar cell, was first invented by Sanyo Corporation. It is an amorphous silicon / crystalline silicon heterojunction solar cell, which is made of a crystalline silicon substrate and an amorphous silicon film. hybrid solar cells. Due to its high photoelectric conversion efficiency, low temperature coefficient and preparation technology under relatively low temperature conditions, HIT solar cells have become one of the key directions of research and development in the photovoltaic industry in recent years. At present, the efficiency of HIT solar cells industrialized by Japan'...

AI Technical Summary

Problems solved by technology

[0006] If a thinner substrate is used to make a HIT solar cell, this will save the material of the substrate; but if a thinner substrate is used to make a solar cell, a part of the incident light will pass through the substrate without being absorbed by the substrate, which will To reduce the conversion efficiency of solar cells, some traditional HIT solar cells directly form a silver layer on the transparent conductive oxide layer on the back. Although the formation of the silver layer can improve the ohmic contact resistance on the back to a certain extent, it can also play a role to a certain reflective effect

However, forming the silver layer directly on the transparent conductive oxide layer will partially oxidize the silver layer during the formation process, thereby weakening the reflection effect of the silver layer; finally, the silver layer is exposed to the external environment, and at this time the silver layer The outer surface is easily affected by the external environment, which will increase the contact resistance between the collector electrode formed on the silver layer and the silver layer, thereby reducing the performance of the solar cell

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