Photoluminescence investigation of CdZnTe: In single crystals annealed in CdZn vapors

CdZnTe:In single crystals were annealed in CdZn vapors through a method involving a high-temperature step and a low-temperature step in sequence. The effects of annealing on the properties of CdZnTe:In were characterized with photoluminescence (PL) spectra. The neutral acceptor bound exciton (A⁰, X) peak, which was on the right shoulder of the neutral donor bound exciton (D⁰, X) peak, disappeared after annealing. A fine donor-acceptor pair structure and its longitudinal optical phonon replicas were clear before annealing. However, both of them became undistinguishable in the PL spectrum of annealed CdZnTe:In. The two phenomena imply that the annealing treatment can remove the impurities from CdZnTe:In wafers effectively. In addition, the intensity of D_complex band fell remarkably after annealing, which confirmed that Cd vacancies were well-compensated in the annealing treatment.