Preparation, photo- and electro-luminescent properties of a novel complex of Tb (III) with a tripod ligand

Abstract

A novel Tb(III) complex TbL (L = tris[2-(2-carboxyphenoxy)ethyl]amine, H 3L) was synthesized and characterized by means of elemental analyses, IR spectra, thermal analyses, and molar conductivity measurement. The photoluminescent properties of the complex were investigated. In addition, PVK doping Tb(III) complex was fabricated as the emissive layer by spin-coating and its electroluminescent properties were studied, in which the structure of the device was ITO (indium tin oxide)/PVK (polyvinylcarbazole)/PVK: TbL/PBD (2-(4-biphenylyl)-5-(4- tert-butylphenyl)-1,3,4-oxadiazole)/LiF/Al. It was indicated that pure green and narrow bandwidth emission at 545 nm from photoluminescence of TbL complex film and the organic electroluminescent device is the characteristic emission of Tb(III) ion, and the electroluminescence spectrum of the device was very similar to that of the photoluminescence of TbL complex film. The lowest triplet level of the ligand was calculated from the phosphorescence spectrum of GdL in N, N-dimethyl formamide (DMF) dilute solution determined at 77 K, and the energy transfer mechanisms in TbL complex were discussed.