Diffusion technology of crystalline silicon solar cell

Abstract

The invention discloses a new diffusion technology of the crystalline silicon solar cell. The diffusion technology mainly refers to a technology which divides the source step into the following steps based on the original technology: low temperature prediffusion, step-ramp-temperature elevation diffusion and high temperature diffusion. The technology can significantly enhance the uniformity of the diffusion, well control the depth and surface concentration of the PN junction and increase the photoelectric conversion efficiency of the crystalline silicon solar cell. The new diffusion technology can be edited easily which only needs to modify the original technological parameters so as to facilitate the operation. The technology is applicable to industrialized production, does not affect the production progress and can be used in large-scale production lines of the solar cell.

Description

technical field [0001] The invention belongs to the field of crystalline silicon solar cell manufacturing, and can be used to improve the diffusion process in the solar cell manufacturing, so that the uniformity of diffusion is improved, thereby improving the photoelectric conversion efficiency of the cell sheet. Background technique [0002] In the solar cell manufacturing process, diffusion is the core process and is used to form the pn junction. There are generally three methods for phosphorus diffusion, one is phosphorus oxychloride (POCl 3 ) liquid source diffusion, the second is chain diffusion after spraying phosphoric acid aqueous solution, and the third is chain diffusion after screen printing phosphorus slurry, and what the present invention adopted is the first method. POCl 3 It is an impurity source that is widely used for phosphorus diffusion at present. It decomposes at high temperature (>600°C) to generate phosphorus pentachloride (PCl 5 ) and phosphorus...

AI Technical Summary

Problems solved by technology

Generally, phosphorus oxychloride (POCl 3 ) has the following disadvantages in the diffusion of liquid sources: (1) poor uniformity; (2) poor repeatability, and there is deviation in the square resistance between the sheets; (3) it is easy to cause a large amount of metaphosphoric acid, which will corrode the quartz parts