Green-emitting (La,M,Tb)OCl (M = Mg, Ca, and Sr) phosphors

May 22, 2018

Title

Green-emitting (La,M,Tb)OCl (M = Mg, Ca, and Sr) phosphors

Author

Sun Woog Kim, Kazuya Jyoko, Toshiyuki Masui, Nobuhito Imanaka

Year

2012

Journal

Optical Materials

Abstract

Green-emitting (La1−x−yMxTby)OCl (0 ⩽ x ⩽ 0.13, 0.03 ⩽ y ⩽ 0.15, M = Mg, Ca, and Sr) single phase phosphors were synthesized using a liquid-phase method and their photoluminescence properties were characterized. The excitation spectrum consisted of a strong broad band from 220 to 290 nm, which corresponds to the 4f–5d transition of Tb3+. The oxychloride phosphors exhibit typical emission peaks assigned to the transition from 5D4 to 7FJ (J = 6, 5, 4, and 3) of Tb3+, and the luminescence emission intensity was successfully enhanced by doping divalent alkaline earth metal ions (M = Mg2+, Ca2+, and Sr2+) into La3+ sites of the host LaOCl lattice. The highest green emission intensity was obtained for (La0.88Ca0.05Tb0.07)OCl, of which the relative emission intensity was 75% of that for a commercial green-emitting (La0.52Ce0.31Tb0.17)PO4 phosphor.

Instrument

FP-8500

Keywords

Fluorescence, Photoluminescence, Optical properties