The effect of dislocations in Cd_0.96Zn_0.04Te single crystal on IR transmittance

To study the effect of dislocations on the crystal properties, large numbers of dislocations were introduced into the Cd_0.96Zn_0.04Te (CZT) wafer (10 mm×20 mm×1.5 mm) by holding the wafer under 100 g-load for 48 h at 650 K. The dislocation density before deformation was measured to be 2.0×10⁴ cm^-2. After the deformation the dislocation density was increased to 6×10⁶ cm^-2. IR transmittance of the CZT wafers before and after deformation was measured by Nicolet Nexus Fourier transform infrared spectrophotometer. The average IR transmittance before deformation was 64%, close to the ideal transmittance and reduced to about 44% after deformation. It is suggested that the large numbers of dangling-bond-electrons introduced by dislocations is responsible for the decrease of IR transmittance.