Electron-cation recombination in rigid organic glasses: simulation of charge distribution and isothermal luminescence kinetics

Abstract

Recent results on isothermal luminescence decays, observed from 10 −8 to 10 4 s after irradiation of a rigid glass at 77 K, are interpreted in terms of tunnelling electron-ion recombination. After 10 −6 s, recombination of isolated pairs is dominant. Electron-ion distance distributions are obtained by computer simulation and used to calculate the corresponding decay kinetics I( t). I( t) ∝ t −1.0 is found with realistic chosen parameters throughout the whole time range investigated experimentally, so that tunnelling recombination is quantitatively consistent with observation. Experimental study at shorter times (10 −8-10 −6 s) indicates a contribution from recombinations of pairs which are not isolated. A very simple computer simulation of these effects is proposed and shown to agree with experiment.