Investigating the possibility of using CdTeSe-based materials for ionizing radiation detectors

The article describes the study of the properties of materials based on CdTe1-xSex suitable for X-ray and gamma radiation detectors. The purpose of the study was to determine by computer modeling the optimal content of impurities and structural defects and the nature of their influence on the electrophysical and detector properties of CdTe(Mn, Mg, Zn)Se, based on the properties of CdTe0. 9Se0. 1 and CdTe0. 05Se0. 95 doped with indium. The values of concentrations Ni, activation energies Ei, and capture cross sections of non-equilibrium charge carriers σi for i-th defects were used as input data for modeling. The author studied the influence of defects on the change in resistivity ρ, concentration of free electrons n0 and holes p0, Fermi level F, life time of non-equilibrium charge carriers τ and charge collection efficiency η of ionizing radiation detectors based on CdTeSe:In at the temperature of 25°C. The paper also highlights the results of quantitative studies of the influence of the impurities and defects content on the properties of CdTe0. 95Se0. 05 with the possible additives of Mn, Mg, and Zn. The regularities of change in ρ, F, η, depending on the content of indium impurities, cadmium and tellurium vacancies were established. The method of achieving a steady high-resistance state was considered. The direction of further research is formulated in order to establish the optimal composition of detector materials based on CdTe1-xSex with additives of manganese, magnesium, and zinc.