Annealing of indium-doped CdMnTe single crystals under Cd vapors

Abstract

Indium-doped Cd1−xMnxTe (x=0.2, CdMnTe) crystals were annealed under Cd vapor atmosphere to improve the properties of CdMnTe. The quasichemical equilibrium model was adopted to calculate the point defect concentration of CdMnTe, and the annealing condition was obtained to maintain the minimum deviation from stoichiometry of CdMnTe. The Indium-doped CdMnTe wafers before and after Cd vapor annealing were characterized by near-infrared (NIR) transmission spectroscopy, IR transmission microscopy, I–V, and IR transmittance. The results indicated that, the Mn composition of the Indium-doped CdMnTe wafers remained unchanged, the concentrations of Te inclusions reduced from (1–5)×105cm−3 to (1–4)×104cm−3, the resistivity increased from (2.0–4.5)×108Ωcm to (2.7–5.3)×1010Ωcm, and the IR transmittance heightened from 17%–21% to 56%–59%. Therefore, it is concluded that the structural and electrical properties of the Indium-doped CdMnTe crystals were evidently improved by the stoichiometric Cd vapor annealing.