A laser texturing study on multi-crystalline silicon solar cells

Abstract

A laser texturing process including laser ablation and post-etching has been developed to form a unique microstructure of pits in craters (PIC) on the front surface of the diamond wire sawn multi-crystalline silicon (DWS mc-Si) wafer. A laser ablation is applied to produce craters with size of tens of microns distributed at the front surface of the wafer, followed by a post-etching process to remove silicon slags produced in the laser process and to form the pits of size in few microns embedded in each crater. The structural, optical and electrical characteristics of the PIC structure are investigated and optimized to achieve a good trade-off between light trapping and recombination. Finally, an applicative laser texturing process is demonstrated for the industrial-grade DWS mc-Si solar cells with an increased efficiency of 19.26% compared with the standard acid textured ones (19.10%).