Photoluminescence of Electrodeposited ZnO Hybrid Thin Films

抄録

Photoluminescence (PL) properties have been studied for electrodeposited porous ZnO thin films hybridized with luminescent rare earth metal complexes and organic molecules. Nanoporous ZnO films were cathodically electrodeposited from the bath containing eosin Y (EY). Various bridging ligands (BLs) having carboxylic acid group as anchor was loaded to ZnO. These BLs have the moiety to coordinate to metal ions and thus can form complexes on ZnO surface by uptaking metal ions such as Eu3+, Tb3+ and Al3+. Fluorescent organic molecules having carboxylic acid group has been chosen and are also attached from their solutions. Some of the hybrid thin films with metal complexes exhibited PL, while none of organic molecules showed PL. Especially efficient were the films with Eu3+ complexes. Its PL intensity was further increased by capping Eu3+ with -diketones. The quantum efficiency for its PL was determined as 21 %when only the ligand to metal energy transfer is taken into account.