Optical Determination of the Valence‐Band Parameters in CdTe

Publisher Website
Google Scholar
Abstract
The set of valence‐band parameters μ, Δ, R0, introduced in the Baldereschi‐Lipari model allows the determination of several energy levels of shallow acceptors in a semiconductor. A critical examination of the methods of determining these parameters is presented. These values are calculated for CdTe using Lipari's analytical expressions for the electronic state energies and experimental data from luminescence and IR spectra of five acceptor impurities. The main conclusions are: 1) the restriction to transition energies (the only energies directly obtained from the experimental spectra) leads to more than one solution for μ, Δ, and R0; 2) when the energy levels of three “unperturbed” P states are known, the valence band‐parameters are unambiguously determined. For CdTe: μ = 0.69 ± 0.03, Δ = 0.12 ± 0.01, R0 = (30 ± 3) meV. Values of these parameters deduced directly from the experimental Luttinger parameters are generally too uncertain to be taken into account.