Process for surface diffusion treatment of silicon chip of solar cell

Abstract

The invention relates to the technical field of solar cell manufacturing, in particular to a process for the surface diffusion treatment of a silicon chip of a solar cell. The process comprises the following steps: firstly, before diffusion source deposition, introducing gases containing chlorine and oxygen into a diffusion furnace to perform chlorine doped oxidization treatment on the silicon chip surface to form a layer of silicon dioxide layer containing chlorine on the surface of the silicon chip; and secondly, performing diffusion source deposition. The chlorine doped oxidization treatment performed before a normal diffusion process can effectively reduce the surface recombination of the silicon chip and realize an excellent surface state, so the performance of finished cells is improved. The novel process avoids increasing novel processing equipment and manpower, influence on productivity and environmental pollution, and is extremely suitable for the industrial application.

Description

technical field [0001] The invention relates to the technical field of solar cell manufacturing, in particular to a surface diffusion treatment process for silicon wafers of solar cells. Background technique [0002] In the recombination mechanism of photogenerated carriers, a very important factor is surface recombination. The surface recombination of solar cell silicon wafers is mainly caused by impurities and defects on the surface. Due to the existence of these impurities and defects, many allowable energy states will be generated in the semiconductor band gap, and the existence of these allowable energy states will cause the trap recombination of carriers. These are unfavorable factors in the solar cell production process. [0003] The current treatment method for reducing the surface recombination of silicon wafers for solar cells is to passivate and anneal the silicon wafers, but this treatment method also brings the defects of increased process steps, equipment and ...

AI Technical Summary

Problems solved by technology

[0003] At present, the treatment method for reducing the surface recombination of solar cell silicon wafers is to passivate and anneal the silicon wafers, but this treatment method also brings the defects of increased process steps, equipment and labor costs

On the other hand, in the current preparation process of crystalline silicon solar cells, there is no direct treatment process for the surface pollution of silicon wafers caused by environmental purification or accidental operation, and these pollutions will cause the performance of finished cells to decline. , causing loss

Especially in the production process of high-efficiency batteries, these factors tend to increase the instability of the production line

In some other semiconductor manufacturing processes, in order to solve this problem, cleaning procedures are carried out before each process. Although this problem can be solved, new process equipment and labor are required. At the same time, a large amount of acid or alkali or strong acid will be used in the cleaning process. Oxidizing agent, which is dangerous to a certain extent and also has adverse effects on the environment