Infrared transmission spectra of Cd_1-xZn_xTe (x = 0.04) crystals

Three indicators (T₁₀₀₀, T₅₀₀₀, and T ₁₀₀₀/T₅₀₀₀) are used to appraise the infrared (IR) transmission spectra for Cd_1-xZn_xTe (CZT) slices. By comparing the values of these three indicators, four typical types of IR spectra are characterized for CZT crystals. The CZT crystals possessing the four types of IR spectra are different in microstructures, especially the densities and sizes of Te precipitates, the free carrier concentrations, and the resistivities. Mechanisms for the elimination of tiny and dense Te precipitates are given by analyzing the variation of the IR transmittance in the range of 500-5000 cm^-1 during the annealing process.