CVD growth of Ge<inf>1−x</inf>Sn<inf>x</inf> using large scale Si process for higher efficient multi-junction solar cells

Multi-junction solar cell efficiency gains due to GeSn and SiGeSn have already shown that a need exists for significant advancement in growing this material in a commercially available CVD chamber. Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Sn <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> films have been grown via an Epsilon RPCVD single wafer CVD deposition tool on Si using a relaxed Ge buffer layer. The material and optical properties of these films have been characterized for various compositions. We present the characterization of strained Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Sn <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> with x = 0.9 % to 7 % and photoluminescence of Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Sn <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> grown via a commercial CVD reactor. This commercial growth accessibility shows that this ternary material should allow for further advancements in multi-junction photovoltaics using Si CMOS compatible processes.