Influence of Te Atmosphere Annealing Time on Cd_1-xMg_xTe Single Crystal Properties and Detector Performance

Cd_1-xMg_xTe single crystals were annealed by Te atmosphere, with a focus on the effect of annealing time on the crystal properties and detector performance. The density of Te inclusions remained stable within the range of 2.15×10⁴-2.22×10⁴ cm². With the increase of annealing time, the content of each element in the crystal was closer to the stoichiometric composition Cd_0.95Mg_0.05Te. No additional surface oxidation was observed. The resistivity first increased and then decreased, reaching a maximum of 6.49×10¹⁰ Ω·cm, which was an increase of three orders of magnitude. After 240 h of annealing, the resistivity decreased to 1.65×10¹⁰ Ω·cm. The optimal annealing conditions were 120 h at 773 K. The detector performance was significantly improved. The electron mobility was enhanced by 7 times, increasing from 52.27 to 366.05 cm²/(V·s). The energy resolution was improved by 1.9 times, reaching 18.4%. And the carrier mobility-lifetime product was increased by 1.7 times, rising from 8.57×10⁵ to 1.42×10^-4 cm²/V.