Synthesis, photophysical and photoelectrical properties of glass-forming phenothiazinyl- and carbazolyl-substituted ethylenes

Abstract

Phenothiazinyl- and carbazolyl-substituted ethylenes have been synthesized and found to constitute electro-active materials with high thermal stability as characterised by thermo-gravimetric analysis. Steady state absorption and luminescence spectra of the synthesized derivatives were examined in detail revealing green-blue emission with efficiency ranging from 13 % to 28 %. Based on the emission spectra of the synthesized compounds Commission Internationale d'Eclairage (CIE) chromaticity coordinates have been obtained. Major luminescence decay time component of ~2.5 ns was determined in dilute solutions of the compounds, whereas significantly shorter one has been estimated in thin films. Electron photoemission spectra of the materials have been recorded and the ionisation potentials of 5.3-5.4 eV have been established. Room temperature hole drift mobilities of the diarylethylenes dispersed in polymeric host approached 10-5 cm2/Vs at high electric fields.