Impurity analyses of Silicon wafers from different manufacturing routes and their impact on LID of finish solar cells

Muhammad Tayyib1, Jan Ove Odden2, Pirmin Preis3, Tor Oskar Saetre1 1University of Agder, Grimstad, Norway /2Elkem Solar AS, Kristiansand, Norway /3ISC Konstanz, Konstanz, Germany

This abstract summarizes the measurements of impurity concentrations in directionally solidified silicon ingots from different feedstocks. The substitutional Carbon and interstitial Oxygen are measured on as-sawn wafers using FTIR. Active iron concentration is mapped on a-Si:H passivated wafers. It is observed that these impurities present in Elkem Solar Grade Silicon (ESS™) concentrations are comparable to the standard polysilicon which are in the acceptable ranges for silicon for solar industry. Th measured LID of the finished solar cells is also comparable.