Excited Electron–Hole States in Molecular Chains

Abstract

The eigenvalues and the eigenfunctions of molecular excitons, charge-transfer excitons, and electron–hole pairs have been found in the approximation of electron and hole transfer between the lowest unoccupied and highest occupied orbitals in a rigid molecular chain of identical photosensitive molecules, the recognized model of organic solar cells. It has been shown that as the Coulomb binding energy decreases, the wave functions become superposition of functions of the increasing number of sites and the decay time, determined by electron or hole transitions, is shorter that the transfer time of the exciton as a whole, so that energy transfer and charge transfer become interrelated processes.