|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.