Dry slotting method for back contact battery

Abstract

The invention discloses a dry slotting method for a back contact battery. The method comprises steps that 1), a treated silicon wafer is subjected to phosphorus diffusion; 2), a layer of polymeric protective coating is printed on an N+ region requiring no etching; 3), continuous passivation and etching of a non-protected region are performed through deep reactive ion etching, parameters are optimized, and an etched profile with a particular sidewall angle and the depth is obtained; 4), boron diffusion of the silicon wafer is performed to obtain a P+ region; 5), etching is performed to remove the remaining polymer protective coating, phosphosilicate glass and borosilicate glass; and 6), a reflective passivation layer is plated, and electrodes are printed. Compared with the prior art, a deep-reaction ion etching machine manufactured by MEMS is utilized for etching and slotting, the etched profile with the particular sidewall angle and the depth is obtained, damage to a crystalline silicon substrate is greatly reduced, battery filling factors are improved, a high performance high performance crystalline silicon battery is obtained, and purposes are achieved.

Description

technical field [0001] The invention relates to a solar cell slotting method, in particular to a dry slotting method for a back contact cell suitable for solar cell slotting. Background technique [0002] Energy and the environment are two major issues facing the 21st century. According to expert estimates, at the current rate of energy consumption, exploitable oil resources will be exhausted in a few decades, and coal resources can only supply about 200 million yuan for human use. year. As a renewable and non-polluting energy source, solar cells can solve the two major problems of energy and environment at the same time, and have broad development prospects. From the perspective of conversion efficiency and source of materials, the focus of future development of the photovoltaic industry is still crystalline silicon solar cells. [0003] Cost reduction and efficiency increase have always been the eternal theme of the photovoltaic industry. With the industry's continuous t...

AI Technical Summary

Problems solved by technology

However, laser grooves on the back are likely to cause damage to the crystal structure, and rear passivated crystalline silicon cells are prone to warping due to the difference in the front and back metal structures. high

In addition, excessive laser damage to the cell will cause a decrease in the open circuit voltage and affect the final performance of the cell.