Absorption and electroabsorption on amorphous films of polyvinylcarbazole and trinitrofluorenone

On disordered films of 1:1 PVK absorption and electroabsorption measurements have been performed in the energy range of the charge transfer absorption band. The spectra which show some similarity to results on amorphous selenium can quantitatively be explained by two charge transfer absorption bands at 2.17 and 2.83 eV originating from transitions between localized molecular states. The electroabsorption response is caused by an energy shift of the molecular states due to the interaction of molecular electric dipoles with the external field. The electroabsorption spectrum rises quadratically with the field strengh and is proportional to the second derivative of the absorption spectrum versus photon energy. The results indicate that the charge transfer from the donor molecule (PVK) to the acceptor (TNF) takes place with the excitation of the complex. Copyright © 1973 WILEY‐VCH Verlag GmbH & Co. KGaA