A hydroxyphenyloxadiazole lithium complex as a highly efficient blue emitter and interface material in organic light-emitting diodes

Abstract

We synthesized a hydroxyphenyloxadiazole lithium complex (LiOXD) as a blue light-emitting and electron injection/transport material to be used in double-layer organic electroluminescent devices. Devices with the concise configuration of ITO/TPD/LiOXD/Al showed bright blue EL emission centered at 468 nm with a maximum luminance of 2900 cd m⁻². A current efficiency of 3.9 cd A⁻¹ and power efficiency of 1.1 lm W⁻¹ were obtained. LiOXD was also examined as an interface material. The efficiency of an ITO/NPB/Alq₃/Al device increased considerably when LiOXD was inserted between Alq₃ and aluminium. The improvement of the device characteristics with LiOXD approached that observed with the dielectric LiF salt.