Diffusion process for reducing doping concentration of N + region of solar cell

Abstract

The invention relates to the technical field of solar cells, in particular to a diffusion process for reducing the doping concentration of an N + region of a solar cell, which comprises the following steps of: S1, prefabricating the solar cell by a worker, and putting a cleaned and textured crystal silicon wafer into a furnace chamber in the prefabrication process; s2, a central control module controls a concentration sensor to detect the doping concentration of the N + region and preliminarily judge whether the diffusion process is qualified or not when preparation of the solar cell is completed, and the temperature rise speed in the diffusion process is adjusted to a corresponding value according to a preset concentration difference value; and S3, when the central control module completes adjustment of the doping concentration, the central control module judges whether diffusion is uniform or not according to a comparison result of the actual square resistance and the preset resistance and further judges the diffusion uniformity according to a difference value of the square resistance and the preset resistance. According to the invention, the doping concentration in the diffusion process is reduced, and the diffusion uniformity is accurately controlled.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a diffusion process for reducing the doping concentration of the N+ region of the solar cell. Background technique [0002] In the preparation process of solar cells, silicon wafers need to go through the processes of texturing, diffusion, etching, coating and printing in sequence. The diffusion process means that the silicon wafer is placed in a diffusion furnace with a quartz boat as a carrier. At a certain temperature, nitrogen and doping elements are introduced into the diffusion furnace to diffuse and deposit PN junctions on the surface of the silicon wafer. Depending on the type of silicon wafer, the doping elements are also different. When the silicon wafer is a P-type silicon wafer, the doping element introduced is phosphorus, and the phosphorus source reacts with the P-type silicon wafer to obtain phosphorus atoms; when the silicon wafer is an N-type silicon wafer, ...

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Problems solved by technology

[0004] To this end, the present invention provides a diffusion process for reducing the doping concentration of the N+ region of a solar cell, so as to overcome the problems of the reduction of the doping concentration in the diffusion process and the lack of accurate control of the diffusion uniformity in the prior art

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