A new zinc–Schiff base complex as an electroluminescent material

Abstract

A Schiff base bis(salicylidene)propylene-1,3-diamine (salpen)2 and its complex with zinc metal as bis(salicylidene)propylene-1,3-diaminatozinc(II) [Zn(salpen)2] were prepared and characterised by various spectral techniques. The zinc complex had high thermal stability (>300°C) as well as high glass transition temperature (>150°C). Optical properties of the metal complex were studied by UV–visible absorption and photoluminescence emission spectroscopy. Multilayered organic electroluminescent devices were fabricated with a structure ITO/α -NPD/Zinc(salpen)2/BCP/Alq 3/LiF/Al, using the zinc complex as an emissive material. The electroluminescence peak emission was centred at 513 nm with colour chromaticity having Commission Internationale d'Eclairage (CIE) coordinates x=0.26 and y=0.50. A bright blue-green emission with a luminance of 1990 Cd/m2 was recorded at 15 V as an optimum voltage.