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In this paper, CdMnTe nanopowders with uniform shapes were prepared through a facile hydrothermal route using 3-mercaptopropionic acid (MPA) as the stabilizer and modifier. The effects of different experimental conditions including Cd-to-MPA ratio, pH value and reaction temperature on the phase composition and formation mechanism of as-prepared nanopowders were studied. XRD results indicated as-prepared CdMnTe nanopowders were pure phase and had cubic sphalerite structure with high crystallinity. SEM and Rietveld refinement clearly showed that the powders were about 10-100 nm in size. In PL measurement, there was a strong luminescence peak in the infrared region 1.717-1.826 eV. Compared with the CdMnTe single crystal, a blue shift of about 0.109 eV indicated a wider band gap. In UV-vis spectra, the absorption peak of the sample blue shifted with the decrease of crystal size, which indicated an obvious quantum confinement effect (QCE) in nanopowders. The optimal conditions for the preparation of CdMnTe nanopowders are 180 °C for 24 h with the molar ratio 1 : 1 of Cd : MPA at pH 13. In particular, the growth kinetics and possible formation mechanism of the nanopowders were proposed.

CdMgTe crystal is a hopeful room temperature radiation detection material because of some potential advantages. The Cd0.95Mg0.05Te ingot with free of inclusion was successfully grown by a modified Bridgman method in this paper. This results was achieved by using a significant excess cadmium and in situ annealing during the growth process. The grown ingot was about 30 mm in diameter and 120 mm in length. The CdMgTe crystal had a cubic zinc-blende structure. The distribution of Mg element along growth direction was homogeneous. In the whole ingot, no inclusions were observed in IR images and as high IR transmittance as above 60% was measured. Raman scattering spectroscopy showed a good crystal quality for CdMgTe crystals. Moreover, the resistivity with 109 Ω cm order of magnitudes for the ingot could be useful for the fabrication of room temperature radiation detector.

Cadmium&ndash, magnesium&ndash, telluride (CdMgTe) crystal was regarded as a potential semiconductor material. In this paper, an indium-doped Cd0.95Mg0.05Te ingot with 30 mm diameter and 120 mm length grown by a modified Bridgman method with excess Te condition was developed for room temperature gamma-ray detection. Characterizations revealed that the as-grown Cd0.95Mg0.05Te crystals had a cubic zinc-blende structure and additionally Te-rich second phase existed in the crystals. From the tip to tail of the ingot, the density of Te inclusions was about 103&ndash, 105 cm&minus, 2. The crystals had a suitable band-gap range from 1.52&ndash, 1.54 eV. Both infrared (IR) transmittance and resistivity were relatively low. Photoluminescence measurement indicated that the ingot had more defects. Fortunately, after annealing, IR transmittance and the resistivity were significantly enhanced due to the elimination of Te inclusions. CdMgTe crystal after annealing showed a good crystal quality. The energy resolutions of the detector for 241Am and 137Cs gamma-ray were 12.7% and 8.6%, respectively. The mobility-lifetime product for electron was 1.66 &times, 10&minus, 3 cm2/V. Thus, this material could be used for room temperature radiation detectors.