Gestörte Excitonen-Zustände und Energieübertragung in plastisch verformten Naphthalin-Kristallen

Abstract

The influence of crystallographic defects on energy transfer processes in naphthalene crystals with and without anthracene doping has been studied. Annealing of single crystals near the melting point and other methods to improve the crystal quality do not change the yield of energy transfer. By plastical deformation three types of disturbed exciton states are created, which act as traps for the migrating electronic excitation energy. The fluorescence spectra of these exciton states are identified asa) a sharp naphthalene line spectrum shifted 165 cm-1 to the red, similar to the impurityinduced so-called X-series;b) a continuous background under the undisturbed naphthalene spectrum;c) emission of excited dimers.Several properties of these spectra are investigated.