title: Comparative investigation on structure and luminescence properties of fluoride phosphors codoped with Er3+/Yb3+.
abstract: This paper reports on comparative investigation of structure and luminescence properties of tetragonal LiYF(4) and BaYF(5), and hexagonal NaYF(4) phosphors codoped with Er(3+)/Yb(3+) by a facile hydrothermal synthesis. The products were characterized by X-ray diffractometer, scanning electron microscope, and photoluminescence spectroscopy. Intense visible emissions centered at around 525, 550 and 650 nm, originated from the transitions of (2)H(11/2) --> (4)I(15/2), (4)S(3/2) --> (4)I(15/2), and (4)F(9/2) --> (4)I(15/2) of Er(3+), respectively, have been observed in all the samples upon excitation with a 980 nm laser diode, and the involved mechanisms have been explained. Based on the green up-conversion emission performance, the Yb(3+) concentrations of Er(3+)/Yb(3+)-codoped LiYF(4), BaYF(5), and NaYF(4) phosphors have been optimized to be 10, 20, and 20 mol*%, respectively. The quadratic dependence of fluorescence on excitation laser power has confirmed that two-photon contribute to up-conversion of the green-red emissions.
authors.affiliation: MOE Key Lab of Specially Functional Materials and Institute of Optical communication Materials, South China University of Technology, Guangzhou 510641, PR China.
authors.forename: X P
authors.initials: XP
authors.lastname: Chen
authors.forename: Q Y
authors.initials: QY
authors.lastname: Zhang
authors.forename: C H
authors.initials: CH
authors.lastname: Yang
authors.forename: D D
authors.initials: DD
authors.lastname: Chen
authors.forename: C
authors.initials: C
authors.lastname: Zhao
mesh_terms: D004871:Erbium / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D049449:Luminescence; D008855:Microscopy, Electron, Scanning; D010758:Phosphorus / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D010758:Phosphorus; D004871:Erbium; D015018:Ytterbium; D005459:Fluorides