Process for preparing selective emitter of monocrystalline silicon solar cell with corrosion slurry method

Abstract

The invention relates to a process for preparing a selective emitter of a monocrystalline silicon solar cell with a corrosion slurry method. A utilized technology is designed based on a common cell plate production line, the original step of growing an antireflecting film by adopting PECVD (Plasma Enhanced Chemical Vapor Deposition) is advanced to the completion of primary diffusion, meanwhile, the printing step and the removing step of corrosion slurry and secondary diffusion of a phosphorus element are added. Silicon nitride is simultaneously utilized as a barrier layer of the secondary diffusion and the antireflecting film of a cell plate. In the invention, the silicon nitride is utilized as the barrier layer of the diffusion, and the step of growing the antireflecting film by adopting the PECVD is an indispensable procedure for producing the monocrystalline silicon cell plate, therefore no addition step is added. The silicon nitride barrier layer of a selective emitter region is broken by the corrosion slurry; compared with a general physical method, the process does not need a special device and high temperature; and compared with a general chemical method, the process is simple. After the process is utilized, the average conversion efficiency of the cell plates produced in batches by a company reaches 18.5%, which is far higher than the industrial average level and achieves world-leading levels.

Description

technical field [0001] The invention relates to the preparation of a monocrystalline silicon solar cell, in particular to a method for preparing a selective emitter of a monocrystalline silicon solar cell by etching slurry. Background technique [0002] In monocrystalline silicon solar cells, there are two main factors that restrict the improvement of conversion efficiency, namely diffusion and metal electrode fabrication. High diffusion concentration is conducive to the formation of good electrode contact characteristics between the electrode and the emission area on the front of the cell. However, it will increase the defect density and reduce the photon absorption efficiency. In order to solve this problem, a selective emitter structure is proposed, that is, a high-concentration deep doping is performed in the area in contact with the electrode, and a low-concentration shallow doping is performed in other areas. , this structure is called a selective emitter, and the se...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to solve the problems of complex process, high equipment requirements and poor emitter effect in the existing emitter preparation technology, and to invent a method that can be completed on a normal single crystal silicon cell production line without adding equipment. , and the high-quality selective emitter technology effectively improves the conversion efficiency of cells and reduces production costs

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