Acid texturing of large area multi-crystalline silicon wafers for solar cell fabrication

Surface texturing of silicon can improve the incident light trapping and hence increase the conversion efficiency of solar cells. The texturing of multi-crystalline silicon (mc-Si) for solar cells with HF/HNO3 acidic solution has been investigated in this work. The recipe of texturing solution was studied to eliminate grain boundaries and defects which may appear in the texturing process. The effect of etch depth on large size solar cell process was also discussed. It is suggested that appropriate etch depth may enhance the surface quality of solar cells without negative effect on the incident light trapping. The result shows that elimination of deep grain boundaries and defects and enhancement of surface quality improves cell performance by increasing the open circuit voltage and the short circuit current.