Concentration and lifetime of nonequilibrium charge carriers in CsI and NaCl subjected to x-ray irradiation

The temperature dependence of radiation-induced conductivity was studied in the range of 80–300 K in alkali halide CsI and NaCl crystals subjected to pulsed x-ray irradiation. It is shown that an increase in electrical conductivity with increasing temperature is satisfactorily accounted for by the thermal separation of electrons and holes with common origins. The concentration and lifetime of conducting electrons, as well as the spatial distribution and the probability of thermal separation of nonequilibrium charge carriers in the common-origin electron-hole pairs after thermalization were estimated. The possible effect of the two commonorigin holes generated in the Auger process on the enhancement of recombination rate of electrons is discussed.