Thermal treatment of indium-doped Cd_1-xZn_xTe single crystals

Indium-doped Cd_1-xZn_xTe (CZT) single crystals were annealed at different temperatures using a Cd_1-yZn_y alloy as the source for the vapor environment control. The effects of annealing temperature on the properties of CZT crystals are discussed in detail. The wafers were characterized by EDX, I-V, IR transmittance, and PL spectra. The results indicated that after annealing, the homogeneities of Cd, Zn and Te distributions were improved, the resistivity of the wafers was enhanced, and IR transmittance was ameliorated. All these improvements increase as the annealing temperature increases up to 1073 K. For the PL spectra of the wafer annealed at 1073 K, the intensity of the D_complex peak decreased after annealing; meanwhile, the (D, A) peak disappeared and the (D⁰, X) peak appeared. It is clear that the optimal temperature of annealing treatment is ∼1073 K using a Cd_1-yZn_y alloy as the annealing source.