Theory of Core Excitons in Semiconductors

Core exciton binding energies are calculated for the Ga 3d‐X 6 conduction band transition inGa‐V compounds and the Si 2p‐Δ 6 transition in Si. Various corrections to the Wannier‐Mott theory are considered. Realistic core hole charge distributions, q ‐ and ω‐dependent dielectric screening and an‐isotropic electron effective masses are taken into account. In the case of Ga‐V compounds, binding energies from the calculation are considerably larger than the Wannier‐Mott values, and close to experimental data. Smaller changes result for Si. The large discrepancies between theory and experiment cannot be resolved in this case.