Correlation between the low-temperature PL spectra and Cd0.9Zn0.1Te quality

摘要

The low-temperature photoluminescence (PL) measurements revealed that Cd(0.9)Zno(0.1)Te PL spectra consisted of three regions: the near-band-edge region with an emission peak I-0 situated at 1.66 eV related to the free and bound excitons, the donor-acceptor region with an emission peak I-1 centred at 1.62 eV related to the impurities, and a defect-band region with an emission peak I-2 centred at 1.50 eV due to the dislocations. The near-band-edge region was dominated by the donor bound exciton peak (I-0) for high-quality Cd0.9Zn0.1Te, but dominated by the acceptor bound exciton peak for low-quality Cd0.9Zn0.1Te. For all high- and low-quality Cd0.9Zn0.1Te, the full width at half maximum of I-0 can be used to evaluate the overall quality of the crystal, and the PL peak intensity ratios of I-1/I-0 and I-2/I-0 could be employed to reflect the impurity concentration and dislocation density of the crystal, respectively.