Influence of random electric fields on luminescence yield and kinetics of insulators

In the present work we investigate theoretically the influence of random electric fields on electron-hole recombination in wide bandgap crystals. Effective Onsager radius and, therefore, electron-hole recombination rate are significantly modified by external electric fields. Electric field distribution functions for point defects and charged dislocations are evaluated analytically. Electron-hole recombination rate decreases with concentration of point defects and dislocations. In simple case of random fields created by charge carriers in highly excited regions the recombination rate is proportional to n 2/3 rather than n , where n is the concentration of excitations. Therefore modification of luminescence kinetics is most pronounced at initial stages of relaxation of highly excited regions.