Jonas Keruckas, J. Gražulevičius, D. Volyniuk
2014
Citations
0
Influential Citations
8
Citations
Journal
Dyes and Pigments
Abstract
Abstract Four derivatives of 3,6-bis(indol-1-yl)-9-phenylcarbazole were synthesized by Ullmann-type coupling including those having methoxy groups at the different positions. Thermal, optical and photophysical properties of the synthesized materials were studied. All the synthesized 3,6-bis(indol-1-yl)-9-phenylcarbazoles are capable of glass formation with the glass transition temperatures ranging from 77 to 95 °C. They exhibit high thermal stability with the 5% weight loss temperatures ranging from 393 to 459 °C. Photoluminescence spectra of the dilute solutions of 3,6-bis(indol-1-yl)-9-phenylcarbazoles are characterized by two well-resolved vibrational peaks at ca. 390 nm and 405 nm. The solid films of the materials also exhibit well-resolved vibrational peaks, however the wavelengths of the maxima are red-shifted by ca. 10 nm. 3,6-Bis(indol-1-yl)-9-phenylcarbazoles were tested in the single-layer organic light emitting diodes as active materials and in phosphorescent light emitting diodes as host materials of emitting layers in combination with Ir(Fppy) 3 as a guest phosphor. Blue single-layer electroluminescent and electrophosphorescent devices with current efficiencies of 3.7–4.1 cd/A and 10.8–12.6 cd/A respectively were fabricated.