Evaluation of energy band offset of Si ₁− x Sn x semiconductors by numerical calculation using density functional theory

We examined the numerical calculation for evaluating the energy band offset of Si 1− x Sn x semiconductors and compared our calculation results with the results of previous theoretical calculation and experimental estimation. By estimating the charge neutrality level of Si 1− x Sn x as a mutual basis level for comparison of the first-principles calculations for different Si 1− x Sn x contents, the calculated valence band offset of Si 1− x Sn x to Si was found to sensitively shift with upward bowing with increasing Sn content compared with that obtained using a conventional linear interpolation model. This is in good agreements with the experimental result.