Vertical unseeded vapor growth of large α-GeTe crystals

Abstract Single crystals of CdTe were grown by the vertical, unseeded vapor growth technique. The faceted, high quality crystals showed higher purity than the ∼6N source materials. The growth rate was found to be strongly dependent on the excess Te present in the growth charge. A maximum growth rate of about 2 g/day was observed at about 0.001–0.02 mol% excess Te at charge preparation. X-ray analysis and metallography of the crystals and mechano-chemical polished slices revealed high quality monocrystallinity. The crystals showed high resistivity (⩾ 10 8 ω cm) and did have nuclear radiation detection properties.