title: Synthesis and characterization of Y2O3:Er3+ upconversion materials with nanoporous structures.
abstract: Y2O3:Er3+ upconversion materials with nanoporous structures were prepared by a hydrothermal method following a post-thermal treatment. The structure and morphology of the materials were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The results indicated that the as-obtained Y2O3:Er3+ powders were of cubic-phase structure, and the nanoporous structure was formed in the annealing process. The optical results indicated that high annealing temperature could improve the upconversion properties, but it could destroy the nanoporous structure. Under 980 nm excitation, red (4F(9/2) --> 4I(15/2) and green (2H(11/2), 4S(3/2) --> 4I(15/2)) upconversion luminescence was observed. The studies on the intensity dependence of upconversion emission indicated that two-photon processes were responsible for the green and red upconversion luminescence. This kind of multifunctional material has potential applications in nanocontainers for use as biomolecule and drugs carriers.
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing JiaoTong University, Beijing 100044, China.
authors.forename: Qipeng
authors.initials: Q
authors.lastname: Lu
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Hou
authors.forename: Aiwei
authors.initials: A
authors.lastname: Tang
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Feng
authors.forename: Feng
authors.initials: F
authors.lastname: Teng
authors.forename: XiaoJun
authors.initials: X
authors.lastname: Liu
mesh_terms: D004871:Erbium / Q000737:chemistry*; D049408:Luminescent Agents / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D016062:Porosity; D013696:Temperature; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry*
chemical_list: D049408:Luminescent Agents; D015019:Yttrium; D004871:Erbium; C091417:yttria