Analysis of the Vibronic Spectra of Perylene-3,4,9,10-tetracarboxylic Dianhydride Adsorbed on NaCl and KCl

Abstract

The vibrational fine structure of the fluorescence spectra of isolated perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules adsorbed on (100) surfaces of sodium chloride and potassium chloride has been studied theoretically and experimentally. In order to analyze the experimentally observed differences in the vibronic spectra of PTCDA adsorbed on the two surfaces, we simulated the spectra by calculating the Franck–Condon factors. The calculated spectra are in excellent agreement with the experiment and indicate that the difference between the two surfaces is the result of a stronger distortion of the molecular geometry on NaCl.