Aspects of charge recombination and charge transport in organic solar cells and light-emitting devices

Abstract

In this thesis, aspects of charge reconbination and charge transport in organic solar cells and light-emitting devices are presented. These devices show promise relative to traditional inorganic semiconductors. We show that the energy splitting between singlet and triplet CT states in organic materials is appreciable and is material and geometry dependent. This prediction is used to guide the development of an OLED with enhanced fluorescence. The effects of nuclear disorder on optical and transport properties in organic semiconductors are examined and a general computational method for carrying out this analysis is described. The function of organic semiconductors is characterized by the interplay between localized and delocalized excited states. We present an ab initio method for obtaining the electronic coupling between CT states and excitons and (discuss the nonadiabatic transitions between these states.