Vertical Bridgman growth and characterization of Cd_0.95-xMn_xZn_0.05Te (x=0.20, 0.30) single-crystal ingots

Abstract

Solid-liquid phase transitions in Cd0.95-xMnxZn0.05Te alloys with x = 0.20 and 0.30 were investigated by differential thermal analysis (DTA). The heating/cooling rates were 5 and 10 K/min with a melt dwell time of 10, 30 and 60 minutes. Cd0.95-xMnxZn0.05Te (x=0.20, 0.30) single-crystal ingots were grown by the vertical Bridgman method guided by the DTA results.Te inclusions (1-20 micron diameter), typical of melt-grown CdTe and Cd(Zn)Te crystals, were observed in the ingots by infrared transmission microscopy. The measured X-ray diffraction patterns showed that all compositions are found to be in a single phase. Using current-voltage (I-V) measurements, the resistivity of the samples from each ingot was estimated to be about 10 5 Ohm•cm. The optical transmission analysis demonstrated that the band-gap of the investigated ingots increased from 1.77 to 1.88 eV with an increase of the MnTe content from 20 to 30 mol. %.