Study of Generation-recombination Processes by the Graph Theory
É. V. Kanaki, Smagul Zh. Karazhanov · American Journal of Condensed Matter Physics · 2013
Generation-reco mb ination (GR) processes of electrons and holes play important role in solar cells by controlling carrier lifetime and influencing on device performance. Co mmonly kinetic theory is used to study the processes. The aim of the article is to use graph theory and represent the GR processes in schematic form: defect states by dots and transitions between them by arcs. The centers of reco mbinat ion have been classified within the defin itions of the graph theory. An equation for the stationary distribution function of defects on states has been derived without constructing the system of kinetic equations. The theory can be helpful for simplification of the model of reco mbination through point defects. It should be based not only on smallest magnitude of the transition probability, but also on the role of the t ransition in the d igraph of states. Distribution function of defects on their states has been found for asymptotic high injection level. We have derived the equation for the rate of the GR processes, which is universal fo r all types of point defects. Models of inertial and static behavior of the recomb ination centers have been discussed and the equations for them have been derived.