Synthesis and characterization of star-shaped organic light emitting materials containing long alkyl chain

Abstract

Star-shaped organic light-emitting materials, CrossTPA (triphenylamine) and CrossCar (carbazole) were prepared through palladium-catalyzed vinylation of organic halides and characterized by UV-visible and photoluminescence (PL) spectroscopy. These materials are soluble in common organic solvents and have good thermal stability up to ca. 300 degreesC. The maximum PL and electroluminescence (EL) peaks of CrossTPA appeared at 510 nm and 520 nm, respectively, which both peaks for CrossCar appeared at 500 nm. The turn-on voltages of CrossTPA and CrossCar were 13.5 V and 19 V for the devices of Al/emissive layer/ ITO LED.