Preparation method for N-shaped back-junction solar cell

Abstract

The invention discloses a preparation method for an N-shaped back-junction solar cell. The preparation method comprises the following steps: (1) cleaning and polishing; (2) diffusing boron and growing an oxidation layers on the front surface and the back surface of a silicon wafer; (3) etching the edge and the front surface of the silicon wafer to obtain a silicon wafer with the oxidation layer on the front surface removed; (4) conducting texturization on the front surface of the silicon wafer through tetramethyl ammonium hydroxide solution; (5) injecting ions; (6) activating at high temperature; (7) depositing silicon nitride on the two surfaces; (8) forming a point contact opening in the back surface of the silicon wafer; (9) printing an aluminum electrode and a silver electrode, and jointly sintering the aluminum electrode and the silver electrode to form metallization contact. According to the preparation method for the N-shaped back-junction solar cell, the oxidation layer retained on the back surface serves as a blocking layer to conduct texturization on the front surface, texturization on the front surface is achieved while the passivation effect of the oxidation layer on the back face is not influenced. In addition, the oxidation layer retained on the back surface serves as a passivation layer, and the oxidation layer or deposited aluminium oxide do not need to be formed at high temperature again, so that the processing steps are greatly simplified.

Description

technical field [0001] The invention relates to a preparation method of an N-type back-junction solar cell, belonging to the technical field of solar cells. Background technique [0002] Conventional fossil fuels are being exhausted day by day. Among the existing sustainable energy sources, solar energy is undoubtedly the cleanest, most common and most potential alternative energy source. Solar power generation devices, also known as solar cells or photovoltaic cells, can directly convert solar energy into electrical energy. The principle of power generation is based on the photovoltaic effect of semiconductor PN junctions. In the prior art, types of silicon wafers mainly include P-type silicon wafers and N-type silicon wafers. Among them, the minority carrier lifetime of N-type silicon wafer is long, and the corresponding recombination is low, so the PN junction of the battery can be prepared on the back of the battery, so there is no dead layer on the front of the battery...

AI Technical Summary

Problems solved by technology

However, due to the diffraction of diffusion, when phosphorus is diffused on the front surface, part of the phosphorus doping will be formed on the back surface, and when boron is diffused on the back surface, boron diffraction will be formed on the front surface, so the diffusion must be done on the side that does not need to be diffused. Silicon oxide or silicon nitride is used to form a barrier layer for diffusion protection, and then removed. This method requires additional steps to deposit a barrier layer at high temperature, which not only makes the battery manufacturing process more complicated, but also due to the increase in high temperature and other process steps, Wafer minority carrier lifetime is affected, which ultimately affects efficiency

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