Novel luminescent yttrium oxide nanosheets doped with Eu³⁺ and Tb³⁺

Novel single-layer rare-earth oxide nanosheets were obtained by the exfoliation of Y_(1-X)RE_XOBr (RE = Eu/Tb) layer. First, the Br^- ions in Y_(1-X)RE_XOBr were exchanged by benzoate ions under microwave conditions. The interlayer benzoate can chelate RE ions in the oxide layer, and change the structure and luminescence properties of the new layer compound. Then, a colloid of yttrium oxide nanosheets was obtained in n-butanol after the ultrasonic treatment of the benzoate-inserted layer for 30 min. The size and thickness of the yttrium oxide nanosheets were ∼800 nm and 0.8 nm, as measured by transmission electron and atomic force microscopies, respectively. A transparent thin film of the yttrium oxide nanosheets on indium tin oxide glass was prepared by electrophoretic deposition. The thin film showed strong red or green emission upon UV-light excitation based on Eu³⁺ and Tb³⁺ ions, respectively. This journal is