Growth and characterization of room temperature radiation detection material Cd_0.95Mg_0.05Te

Recently, researchers were interesting in exploring alternative materials for well-studied CdZnTe which was the key material of radiation detection. Cadmium Magnesium Telluride (Cd_1-xMg_xTe) crystal was regarded as promising one for room temperature X-ray and gamma-ray detectors due to some potential advantages. In this paper, two large-size Cd_0.95Mg_0.05Te ingots with 30 mm diameter and over 100 mm length were successfully grown by a modified vertical Bridgman method. Two modifications, including Cd excess or Te-rich condition and the accelerated crucible rotation technique (ACRT), were applied in growing process to decrease defects, enhance resistivity and homogenize component distribution. The results indicated that both ingots had a cubic zinc-blende structure. The distribution of Mg element in the ingots along axial direction was very homogeneous. The energy band gap of Cd_0.95Mg_0.05Te was close to Cd_0.9Zn_0.1Te. Low density of Te inclusions (10³ cm^{− 3} order of magnitudes) and high IR transmittance (over 60%) showed the good crystal quality. Raman scattering spectroscopy also showed a good crystal quality for Cd_0.95Mg_0.05Te crystals. Thus, Cd_0.95Mg_0.05Te crystals could be a promising radiation detector material.