Optical temperature sensing properties of Stokes fluorescence-based high color-purity green-emitting Sr2Gd8(SiO4)(6)O-2:Er3+ phosphors

Abstract

Fluorescence intensity ratio (FIR)-based optical thermometry has attracted a great deal of attention because it allows accurate and reliable temperature measurements with high spatial resolution and realtime monitoring. Herein, we report the novel Sr(2)Gds(SiO4)(6)O-2:Er3+ (SGSO:Er 3(+)) phosphor as an optical thermometry material. The sol-gel method is used to synthesize the oxyapatite structured SGSO:Er3+ phosphors, which exhibits a rod-like morphology. The photoluminescence spectra of SGSO:Er3+ phosphors displays two distinct green emission bands corresponding to the electronic transitions 2H(11/2) -> 4(I15/2) and 4(S3/2) -> 4(I15/2). The temperature-induced variations in the FIR result in a maximum sensitivity of 3.4 x 10(-3) K-1 at 463 K. Further, the CIE chromaticity coordinates do not shift from the green region when the temperature is increased from 303 to 483 K and the color purity only decreasing from 77.6 to 71.4%. The SGSO:2Er(3+) phosphor exhibits the color-purity of 93.5% when excited with low-energy electron beam. These results suggest that the SGSO:2Er(3+) phosphor is a promising material for optical temperature sensors and display devices. (C) 2018 Elsevier B.V. All rights reserved.