Hot luminescence study of the intramolecular thermal bath of aromatics

We report a hot luminescence study of the vibrational relaxation in the S₁ state of anthracene and perylene in various solid matrices at 4.2 K. A set of relaxational data is evaluated and presented. The need of an external thermal bath at the initial stage of relaxation of these molecules is discussed. Some problems of distinction of resonant secondary emission components are illustrated by the mixed crystal spectra. A novel approach to the separation of scattering and hot luminescence in strongly inhomogeneous spectra at resonant excitation is introduced.