Polarized electroluminescence from smectic mesophase

Abstract

Electrically pumped light emission was observed from a smectic mesophase of liquid-crystalline oxadiazole; 2,5-hexyloxybiphenyl-hexyloxyphenyl-oxadiazole (HOBP-OXD), which exhibits high electron transport capability. The light-emitting diode consisted of the HOBP-OXD film, a copper phthalocyanine vacuum deposited film as a hole injection layer, and a tris-(8-hydroxyquinoline) aluminum vacuum deposited film as an electron injection layer. The emission was linearly polarized originating from highly oriented molecular textures in the smectic mesophase with a degree of orientational order of 0.32. © 1998 American Institute of Physics.