Defect-induced optical transitions in CdTe and Cd_(0.96)Zn_(0.04)Te

摘要

Within a model of the compensated shallow acceptor classical impurity band, we study the optical absorption of CdTe and Cd_(1-x)Zn_xTe, at energies of 20―70 meV below the energy gap connected with acceptor―conduction band transitions. The shape of the absorption edge is fitted by Monte Carlo numerical simulations and we estimate the total density of charged impurities, which is hardly detectable by other experimental techniques. The activation energy ≈59 meV and density ～10~(14) cm~(-3) of the dominant shallow acceptor level are reported.