Recombination in amorphous materials as a continuous-time random-walk problem

Abstract

In this paper we study carrier recombination in amorphous materials. The dynamics is described through continuous-time random walks, for which several stepping-time distributions are used. We determine the probability of the carrier being captured at the recombination centers from the number of distinct sites visited in the walk. The overall process is then modeled in the framework of chemical reactions. Our approach unifies the derivation of decay laws due to recombination and allows a critical evaluation of former results; these conclusions are verified both by analytical and by numerical methods.