Uniformity of Cd 1 - xZn xTe grown by high-pressure Bridgman

We have employed both low-temperature photoluminescence (PL) spectroscopy and high-spatial-resolution, room-temperature PL mapping to determine composition variation in Cd _{1 - x}Zn _xTe grown by high-pressure Bridgman. Composition variations Δx of approximately 5-10% are observed between tip and heel of an approximately 13 cm long boule, while fluctuations of 1-2% are observed within a single, detector-scale sample. We also show that there are great discrepancies in the calculated zinc concentration, depending on which expression for E_g( x) is chosen from the literature. We have performed high-resolution, triaxial X-ray analysis on selected samples to determine which of the published relations is most accurate for our material. We have also examined the relationship between the low-temperature PL spectrum and detector performance, and found that the line width of the donor-bound-exciton peak can be used as a predictor of performance.