Electron irradiation and trapping centres in zinc sulphide single crystals

Electron radiation damage of zinc sulphide crystals at room temperature showed the creation above different threshold electron energies of two trapping states with glow peaks at 195 and 235 °K. The variation with incident electron energy of the theoretically evaluated numbers of displaced primary atoms for various displacement threshold energies has been correlated with experimentally induced and determined point defect concentrations (the thermoluminescence intensity enhancement) and used to give a precise value of the threshold energy for primary atomic displacement. The experimental enhancement of the 195 °K glow peak yielded a sulphur displacement threshold energy of (15.4 ± 0.5) eV (corresponding to an incident electron energy of (190 ± 5) keV). The experimental enhancement of the 235 °K glow peak was used to determine the zinc displacement threshold energy of (9.7 ± 0.2) eV (an incident electron energy of (235 ± 5) keV). The isochronal and isothermal annealing characteristics of the glow peaks have also been determined.