Currently, industrial manufacturing of solar cells is dominated (62%) by the usage of DWS mc-Si wafers, owing to reduced kerf-loss leading to high through put. However, as a result, these wafers becomes highly polished, introducing a challenge in texture process. A team of researchers led by Dr Prabir K. Basu at NCPRE-crystalline silicon laboratory invented an additive-free and cost effective chemical recipe, utilized in texturing of large area DWS mc-Si wafers. These additive-free acid-textured wafers and finally solar cells exhibited excellent optical, electronic and electrical properties compared to the existing additive-based acid textured wafers and cells.
Detailed chemical cost analysis suggests that the additive-free acid texturing process can reduce the chemical cost involved in preparing the acid bath by 60% compared to existing additive-based acid texturing process. Successful demonstration of the texturing process was done at three solar cell manufacturing sites in India. Details of the invention have been featured in the form of patent, publications in reputed scientific journals and presentation in renowned conferences.