3,6-Bis(indol-1-yl)-9-phenylcarbazoles as electroactive materials for electrophosphorescent diodes

作者：Keruckas J; Grazulevicius J V^*; Volyniuk D; Cherpak V; Stakhira P

来源：Dyes and Pigments, 2014, 100: 66-72.

DOI：10.1016/j.dyepig.2013.07.020

• Carbazole
• Indole
• Molecular glass
• Organic light-emitting diodes
• Iridium complex
• Host-guest films

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 degrees C. They exhibit high thermal stability with the 5% weight loss temperatures ranging from 393 to 459 degrees 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.

• 出版日期2014-1