A novel amorphous oligo(phenylenevinylene) dimer with a biphenyl linkage center and fluorene end groups for electroluminescent devices

Abstract

A new type of oligo(phenylenevinylene) dimer, 2,5,2′,5′-tetra(9,9′-dihexylfluorenyl)biphenyl (TFB), with a biphenyl linkage center and four fluorene end groups, has been synthesized by the Wittig reaction. The full characterization of its structure and optical properties, as well as the performance of its electroluminescent devices are presented. TFB shows strong blue fluorescence both in solution and as a solid film. High-quality films of TFB for light-emitting devices (LEDs) can be fabricated both by vacuum evaporation and the spin-coating technique, which is very special and interesting. Single-layer and multi-layer light-emitting devices using TFB as the active layer all show efficient blue emission.