Luminescence and Exciton Lattice Interaction in α-Perylene Crystals

Abstract

A new luminescence band associated with the free exciton in α-perylene has been found out at room temperature. The energy separation between the free and the self trapped states is determined to be 650 cm -1 , which gives the exciton bandwidth of 2310 cm -1 . The interaction among translationally equivalent molecules is much smaller than that among inequivalent molecules. The character of the Y state is briefly discussed in connection with the adiabatic potential energy curve.