Optical band gap of the ternary semiconductor Si1−<i>x</i>−<i>y</i>Ge<i>x</i>C<i>y</i>

Abstract

Single-crystal alloys of diamond with Si and Ge are investigated theoretically. An indirect band gap Γv25′ → Δc1 is found for the new semiconductor Si1−x−yGexCy over most compositions x and y, with an indirect Γv25′ → Lc1 gap found for the remaining compositions. The estimated band gaps span the 0.62–5.5-eV-range. Predictions are made for band gap versus lattice parameter in the new alloy semiconductors Si1−xCx and Ge1−xCx.