Heating-rate method for determination of kinetic parameters from thermally stimulated conductivity and luminescence

Abstract

A method for determining the ratio of the recombination and trapping coefficients and the relative density of inactive deep traps on the basis of simultaneously measured thermally stimulated conductivity (TSC) and luminescence (TSL) is derived in the case of a temperature-dependent free electron lifetime. The method is based on the relation between the preexponential factor of the temperature dependence of the thermally stimulated free electron density (TSC) and the occupancy of active traps. Values of the preexponential factor and the trap depth corresponding to different values of the relative TSC intensity can be found from the TSC peak measured at different heating rates of the sample. Similar analysis of the TSL peak produces accurate values of the trap depth as well. The method for determination of the trap depth also yields accurate results from multipeak TSC and TSL curves. These results are more accurate than those found using the heating-rate method of Haering and Adams [Phys. Rev. 117, 451 (1960)], the initial-rise method of Garlick and Gibson [Proc. Phys. Soc. (London) 60, 574 (1948)], and the fractional TSL method of Gobrecht and Hofmann [J. Phys. Chem. Solids 27, 509 (1960)].