Large band gap bowing of InxGa1−xN alloys

Abstract

Band gap measurements have been performed on strained ${\mathrm{In}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ epilayers with $\text{x⩽0.12.}$ The experimental data indicate that the bowing of the band gap is much larger than commonly assumed. We have performed first-principles calculations for the band gap as a function of alloy composition and find that the bowing is strongly composition dependent. At $\text{x=0.125}$ the calculated bowing parameter is $\text{b=3.5\hspace{0.17em}}\mathrm{eV},$ in good agreement with the experimental values.