Study of Te precipitated phase in CdZnTe crystals

The precipitated phase in Bridgman-grown CdZnTe crystals has been investigated by transmission electron microscopy (TEM), transmission infrared microscopy, infrared transmission spectroscopy and differential scanning calorimetry (DSC). Origination and distinction between Te precipitate and Te inclusion in CdZnTe crystals are discussed. The experimental results of infrared spectra and DSC technique show that when the concentration of Te precipitates/inclusions (wT e) is higher than 0.6 wt%, the IR transmittance is lower than 55% and then quickly decreases as wT e increases. This can be explained by using the optical transition within the valance band of II-VI semiconductor.