Correlation between Te-rich particles in CdZnTe crystals and corresponding PL spectra

Micron-scale Te-rich particles presented in CdZnTe crystals were directly observed using infrared transmission microscopy (IRTM). The generation of various Te-rich particles was discussed in conjunction with the growth conditions. In order to evaluate the impurities and defects behaviors, and to examine the crystalline quality, photoluminescence (PL) spectra were obtained at 10 K. The corresponding resistivity was evaluated simultaneously. The correlation between different shaped Te-rich particles in CdZnTe crystals and the corresponding PL spectra at 10 K was concluded compared with the characterized photo-peak in PL spectra. Well-defined sphere, hexagonal and triangular shaped incoherent Te-rich particles were generally presented in CdZnTe crystals grown from the charge with excess Te, which the (D⁰, X) peak usually dominated in the PL spectra. Cross-shaped Te-rich particles were found in CdZnTe crystals grown under stoichiometric condition where the DAP peak dominated in the PL spectra. Star-shaped Te-rich particles were normally obtained in CdZnTe crystals under Cd-rich conditions where the FWHM of (D⁰, X) peak was wide.