Effect of electromagnetic radiation of spark discharge on dielectric properties of Cd1– <i>x</i> Zn <i>x</i> Te crystals in the low-frequency region

This work aims to investigate the influence of extremely low-intensity ultra-high-frequency electromagnetic radiation (UHF EMR) generated by a controlled spark discharge on the low-frequency dielectric properties of Cd1–xZnxTe (CZT) crystals and to clarify the role of point defect complexes in this process. The study focused on Cd1–xZnxTe single crystals (x = 0.10–0.20) grown from a melt under high inert gas pressure, from which rectangular samples were prepared. The real (ɛ′) and imaginary (ɛ″) parts of the complex permittivity were measured at frequencies of 1–33 kHz using a capacitive method, and the energy spectrum of localized states (LS) was determined by scanning photodielectric spectroscopy (SPDS) before and during exposure to UHF EMR. The results showed stepwise changes in ɛ′ and ɛ″ under irradiation, with relaxation effects persisting after exposure. The frequency dependence of 〈|Δɛ′|〉 and 〈|Δɛ″|〉 followed a power-law decrease. SPDS revealed a rearrangement of LS, including the disappearance of states in the Ev + 0.20–0.40 eV range and the emergence of new ones, indicating reconstruction of point defect complexes. These findings confirm that point defect complexes play the key role in the dielectric response of CZT crystals to weak electromagnetic fields and should be considered in the design of radiation detectors and electronic devices.