RGS-Silicon - Material Analysis and Solar Cell Processing

In this work, RGS (Ribbon Growth on Substrate) a ribbon silicon material from Bayer AG is characterised, and solar cells from this material, which is presently under development, are processed. Due to the very fast casting process and the lack of kerf losses RGS could be a cost effective alternative to standard cast crystalline silicon wafers in the near future. RGS wafers are characterised with regard to diffusion lengths, crystal defects, transport properties and lifetimes in order to get a deeper inside in the material properties. A solar cell process is developed and optimised based on these results, which takes into account the special needs and properties of RGS silicon. Intensive gettering and H-passivation studies as well as a mechanical texture of the wafer surface led to cell efficiencies of 12 (2x2cm2), which is an overall record on this material