Mixed Ligand Orange Emitter Zinc Complex for Organic Light Emitting Diodes

Abstract

We report synthesis, characterization and use of ternary zinc complex as emissive and electron transport material in organic light emitting devices (OLED). 5,7-dimethyl-8-hydroxyquinoline have been used with 2-(2-hydroxyphenyl) benzoxazole to synthesize (2-(2-hydroxyphenyl)benzoxazolato) (5,7-dimethyl-8-hydroxyquinolinato)zinc(II) [Zn(HPB)(Me2q)]. The complex possessed high thermal stability and having good film forming property. Optical properties of the synthesized complex have been studied by UV-visible absorption, photoluminescence and transient photo-luminescence spectroscopy. Synthesized material shows quite good efficiency in multilayered device structure ITO/α-NPD/Zn(HPB)(Me2q)/BCP/Alq3/LiF/Al with maximum brightness of 4017 cd/m2 having electroluminescence spectral peak emission centered at 567 nm. Electron mobility of the synthesized complex was found to be 1.5 x 10-6-1.2 x 10-5 cm2/V sec. for electric field range 1000-1200 (V/cm)1/2 and hence can be used as electron transport material in OLEDs.