Deep levels and compensation in gamma-irradiated CdZnTe

The behavior of detector-grade Cd0.9Zn0.1Te in a radiation-hostile environm ent has been investigated by studying the effects on the material defective states induced by gamma irradiation. The detector performance is strongly affected by the presence of charge-trapping centers which may also interven e in the material compensation properties. We have investigated by photoind uced current transient spectroscopy analyses the evolution with increasing irradiation dose of the deep levels both present in the as-grown material a nd induced by the ionizing radiation. A significant correlation between the material resistivity and some deep levels behavior has been observed. We h ave compared this trend to the results obtained from gamma -irradiated CdTe :Cl to better understand the role deep traps play in the compensation proce ss of II-VI materials. (C) 2000 American Institute of Physics. [S0003-6951( 00)00146-7].