Momentum dependence of the excitons in pentacene

J Chem Phys. 2012 May 28;136(20):204708. doi: 10.1063/1.4723812.

Abstract

We have carried out electron energy-loss investigations of the lowest singlet excitons in pentacene at 20 K. Our studies allow to determine the full exciton band structure in the a∗, b∗ reciprocal lattice plane. The lowest singlet exciton can move coherently within this plane, and the resulting exciton dispersion is highly anisotropic. The analysis of the energetically following (satellite) features indicates a strong admixture of charge transfer excitations to the exciton wave function.