PL and EL properties of oligo(p-phenylene vinylene) (OPPV) derivatives and their applications in organic light-emitting diodes (OLED)

摘要

This paper reports the photoluminescence properties and the performance enhancement of organic light-emitting diodes (OLEDs) of a series of well-defined π-conjugated rigid rod oligomers analogous to poly(p-phenylenevinylene) (PPV). They are based on benzene-1,4-bis(phenylene vinylene) (OPPV) with electron-withdrawing (nitro) or electron-donating (methyl and dimethylamino) substituents in para-position of the terminal rings of the molecule. Substitution with methoxy and a long alkoxy group (hexadecyloxy) in 2,5-positions is also examined. Photoluminescence spectra obtained from films are discussed and compared to those previously reported in tetrahy-drofuran solutions. OPPV oligomers were then used as emissive material in OLEDs and the I- V-L characteristics of the devices are presented. The results show that donating groups placed on the OPPV backbone increases the performances of the devices.