Spin—lattice relaxation and thermal deactivation of X traps in 4,4′-dichlorobenzophenone

Abstract

The phosphorescence intensities and decay times of X traps in neat 4,4′-dichlorobenzophenone crystals were measured as a function of temperature. The study of a very deep trap (Δ = 421 cm −1) is particularly attractive because we can observe successively, as the temperature increases, the influence of the spin—lattice relaxation and the thermal deactivation upon the observed decay times. The values of trapping and detrapping rate constants are given and discussed in terms of a random walk diffusion model.