title: Size/morphology induced tunable luminescence in upconversion crystals: ultra-strong single-band emission and underlying mechanisms.
abstract: In this work, we present a two-step method to controllably synthesize novel and highly efficient upconversion materials, Lu5O4F7:Er(3+),Yb(3+) nano/micro-crystals, and investigate their size/morphology induced tunable upconversion properties. In addition to the common phenomenon aroused by a surface quenching effect, direct experimental evidence for the regulation of phonon modes is obtained in nanoparticles. The findings in this work advance the existing mechanisms for the general explanation of size/morphology induced upconversion features. Because of the adjustment of phonon energy and density as well as the surface quenching effect, the biocompatible Lu5O4F7:Er(3+),Yb(3+) nanoparticles exhibit an ultra-strong single-band red upconversion, rendering them promising for biomedical applications.
authors.affiliation: Department of Chemical & Biomolecular Engineering and Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, USA. luyi.sun@uconn.edu.
authors.forename: Zhaofeng
authors.initials: Z
authors.lastname: Wang
authors.forename: Songshan
authors.initials: S
authors.lastname: Zeng
authors.forename: Jingfang
authors.initials: J
authors.lastname: Yu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Ji
authors.forename: Huidan
authors.initials: H
authors.lastname: Zeng
authors.forename: Shuangyu
authors.initials: S
authors.lastname: Xin
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Wang
authors.forename: Luyi
authors.initials: L
authors.lastname: Sun
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D056831:Coordination Complexes / Q000737:chemistry; D004871:Erbium / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008163:Luminescent Measurements; D008187:Lutetium / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D015018:Ytterbium / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D056831:Coordination Complexes; D008187:Lutetium; D004871:Erbium; D015018:Ytterbium