Kinetics of non-steady state diffusion-controlled tunnelling recombination of defects in insulating crystals

The theoretical basis is developed for a previously presented method of experimental detection of reactions in insulators controlled by the interaction of diffusive defects and subsequent tunnelling recombination. The method involves measuring the increase (or decrease) in the recombination luminescence after stepwise increase in the temperature (i.e. defect mobility). It is shown theoretically that the inertial (about 100-300 s) transient process observed in pure solids-KCl, KBr, alpha -Al₂O₃ and the Na salt of DNA-strongly suggested self-trapping of the carriers participating in recombination whereas treatment of the defect (polaron) motion in terms of a continuous approximation allows one to estimate characteristic parameters of the motion and recombination.