Spectral sensitization of photoconductivity of poly(<Emphasis Type="Italic">N</Emphasis>-epoxypropylcarbazole) and benzaldehyde diphenylhydrazones by pyrylium dyes and their heteroanalogues

The sensitizing activity of γ-pyrylocyanines and their heteroanalogues with respect to poly(N-epoxypropylcarbazole) and benzaldehyde diphenylhydrazones was studied. The influence of the dye anion and cation on its sensitizing ability was shown: the change in the sensitizing activity upon introducing a complex metal-containing anion into the dye molecule is due to a change in the donor-acceptor properties of the molecule and redistribution of the probabilities of excited-state deactivation processes. It was found that the maximum sensitization efficiency of pyrylium dyes was attained at the difference of 0.26–0.28 V between the electrochemical oxidation potentials of the sensitizer dye and the organic semiconductor.