Das Energiespektrum und die mittlere freie Bahn der deformierenden Excitonen in Molekularkristallen

A study is made of the energy spectrum of a deforming exciton and its temperature dependence in molecular crystals. The mean free path and diffusion coefficient of the deforming exciton with respect to multi-phonon collisions with crystal lattice vibrations are theoretically determined. The possibility of distinguishing the propagation of excitation in molecular crystals in the form of deforming excitons from that in the form of non-deforming excitons and from the propagation of excitation by random jumps from one molecule to another is discussed on the basis of the theoretically derived temperature dependence of the diffusion coefficient of the deforming exciton.