A kind of preparation method of black silicon MWT back contact cell

Abstract

The invention discloses a preparation method of a black silicon MWT back contact battery. The preparation method of the black silicon MWT back contact battery comprises the following steps of firstlycarrying out damage layer removing treatment on a silicon wafer; printing metal paste at a to-be-perforated position on the front surface of the silicon wafer, carrying out black silicon texturing onthe silicon wafer, perforating the surface, on which the metal paste is printed, of the silicon wafer, and forming a regular nano light trapping structure on the surface, on which the metal paste is not printed, of the silicon wafer; and finally carrying out diffusing, coating, printing, sintering and laser marking isolation processes in sequence. Perforating of the silicon wafer is achieved through coordination of metal paste printing and black silicon texturing, and a laser drilling procedure is omitted. The method is simple in operation, low in equipment input and free of laser drilling equipment; most importantly, the problems of fragment rate increase and yield declination caused by laser drilling can be solved; meanwhile, the battery conversion efficiency can be further improved by about 0.4% through matching black silicon texturing; and compared with a traditional preparation technology of the MWT back contact battery, the preparation method has the advantage that the single watt cost of the battery can be reduced by 10-15%.

Description

technical field [0001] The invention belongs to the technical field of solar cells, in particular to a method for preparing a black silicon MWT back contact cell. Background technique [0002] The traditional MWT back contact battery technology uses laser drilling and rear wiring technology to eliminate the main grid lines of the front electrodes, and the current collected by the fine grid lines of the front electrodes is led to the back through the silver paste in the holes, so that the positive and negative electrodes of the battery The dots are distributed on the back of the cell, which effectively reduces the shading of the front grid lines and improves the conversion efficiency; therefore, for the traditional MWT back-contact cell technology, the first step is to perform laser drilling, but laser drilling is due to The stress problem of the cell will lead to an increase in the fragmentation rate and a decrease in the yield rate. This problem has always been one of the k...

AI Technical Summary

Problems solved by technology

The metal paste of the present invention is combined with the wet chemical method of black silicon texturing to realize surface nanostructure morphology and chemical corrosion perforation. The effect of light can significantly reduce the reflectivity of the silicon wafer surface. At present, enterprises in the forefront of the industry have achieved mass production of black silicon with ordinary battery technology.

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