Radiation sensor based on thin-film CdTe/CdS device structure and its radiation resistance under high-intensity hydrogen plasma

Abstract

In this work, the ability of CdTe/CdS thin-film device structures prepared by the hot-wall method to detect ionizing radiation was investigated. The samples were fabricated with a structure typical of CdTe/CdS-based solar cells and exhibit radiation sensitivity even without the application of an external voltage. This allows such structures to be used as low-voltage radiation sensors. An investigation of the radiation resistance of the structures, namely, the effect of irradiation with high-intensity hydrogen plasma H2+ on the crystal structure and performance, was carried out. It was shown that the device structures remained operational after two plasma pulses at an ion density of 2 × 1023 m-2 and an energy density of up to 0.2 MJ/m2. With further exposure to plasma, the device structures deteriorated, first, due to gradual sputtering off of the back contact, and, second, as a result of diffusion processes that occurred when the structures were heated to high temperatures, due to which the entire volume of the CdTe base layer got converted into a CdSxTe1-x solid solution.