Electroluminescent applications of a cyclic carbazole oligomer

Abstract

A cyclic carbazole oligomer for organic light-emitting diodes is described. This cyclic oligomer has a high glass transition temperature (105 °C), and high quality amorphous film can be prepared by the conventional spin-coating technique. We examined the characteristics of this cyclic oligomer for electron transport layer applications. The device structure of indium tin oxide/hole transport layer/electron transport layer/Al was used. The EL device exhibited green light with a luminance of 60 cd m ^–2 at 15 V and the external quantum efficiency was 0.44%.