Characterization of CdTe:Zn:V crystals grown under microgravity conditions

摘要

CdTe:Zn:V crystals grown by the seeded Bridgman method in microgravity conditions during the STS95-Spacelab-AGHF-l mission and in the ground laboratory (1-g) were analyzed and compared. The results obtained clearly show that the structural quality of the space crystal is better. Density of inclusions, concentration of dislocations, and presence of stresses are lower in the microgravity-grown (μ-g) crystal. The 1-g crystal contains twins and grains from the beginning of the growth process, that is, from the near-seed region. In general, the concentration of inclusions and amount of segregated impurities on the 1-g crystal are larger than in the μ-g crystal. X-ray rocking curves and low-temperature photoluminescence spectra demonstrate the relatively high quality of both crystals on a microscale at the beginning of the growth and show that the 1-g conditions were worse at the end. The results of this investigation demonstrate a positive role of contactless growth and μ-g conditions in the melt in suppressing the creation of inclusions and dislocations.