Preparation method of novel all back electrode crystalline silicon solar cell

Abstract

The invention relates to a preparation method of a novel all back electrode crystalline silicon solar cell. The method comprises the following steps: pre-cleaning, injury removal, mask protection, preparation of a pyramid texture, second preparation of the texture, texture aftertreatment, post cleaning, all back electrode fabrication and the like. The crystalline silicon pyramid texture with a nano structure shape prepared by the method has a nano short column which covers the overall pyramid surface; the pyramid top is still clear; through a test, the surface reflectivity of the texture is reduced to 3.7% from 12.5% of a conventional process.

Description

technical field [0001] The present invention mainly relates to a preparation method of a solar cell with a crystalline silicon material as a substrate, especially a new type of full-back electrode crystal based on the improvement of the textured surface structure of the cell, which can achieve higher photocurrent density and cell conversion efficiency Method for the preparation of silicon solar cells. Background technique [0002] Due to its very unique device structure advantages and good potential to achieve higher photoelectric conversion efficiency, all-back electrode cells have been the focus of research and attention by many institutions for a long time in the past until now. Its primary feature is that all the grid electrodes are transferred to the back of the cell, which directly eliminates the light absorption loss caused by electrode shading and reflection, so that the device structure can obtain a higher photocurrent density than other front cell structures. Impr...

AI Technical Summary

Problems solved by technology

However, the existing alkali texturing treatment still has some limitations: (1) The size of the pyramid structure on the surface of the substrate after texturing is often uneven and widely distributed, and most of them only reach 12-14% (350-1100nm) of effective reflection (2) General high-concentration alkali solution polishing to remove surface damage will lead to excessive thinning of silicon wafers, which will easily lead to high fragmentation rate and silicon wafers in the follow-up process Problems such as adhesion and warpage occur, and these conditions are more prominent especially in thin silicon wafers; (3) The density of micro-defects on the substrate surface will increase significantly after texturing, and there is a lack of targeted cashmere in the middle of the usual cleaning and texturing process. Optimizing surface morphology and removing defects may be detrimental to the high-quality implementation of subsequent passivation and emitter junction manufacturing processes; (4) In order to remedy the lack of anti-reflection effects of general suede surfaces, in the existing battery technology, It is achieved by using laminated anti-reflective coatings, which will increase the cost per watt of the battery

[0004] Therefore, the existing alkali texturing process on the surface of silicon wafers has certain technical defects when applied to full-back electrode batteries. It is necessary to design a texturing process for full-back electrode batteries to greatly reduce the surface reflectance of silicon wafers. , and ultimately improve the electrical performance and yield of the battery

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