Luminescent Properties of A Novel Terbium Complex Tb(o-BBA)3(phen)

A novel rare earth complex of terbium ion with 2-benzoylbenzoic acid and 1, 10-phenathroline (Tb(o-BBA)3 (phen), o-BBA = 2-benzoylbenzoic acid, phen = 1,10-phenathroline) was used as an electroluminescent material for the first time. The Tb complex was blended with poly(N-vinylcarbazole) (PVK) in different weight ratios and spinn to coated into films (noted as PVK:Tb films). The photoluminescence (PL) properties of films were investigated and the optimum weight ratio between PVK and Tb(o-BBA)3(phen) was found to be 3:1. Monolayer devices with the structure ITO/PVK: Tb/Al were fabricated and emitted green light, which was characteristic of Tb3+ emission. The results show that mechanisms for PL and EL are different. The PL is considered to be caused because of energy transfer and direct excitation to the Tb(o-BBA)3(phen) molecule, while EL is mainly on charging trapping.