Novel Phosphor GdY2SbO Co-Dope with Eu3 and Bi3 for Optical Thermometer

Abstract

A series of GdY2SbO7:Bi3+, Eu3+ phosphors were prepared using the conventional solid-state reaction. In this study, the photoluminescence properties and temperature sensitivity of the samples were investigated. When Bi3+ and Eu3+ were codoped into GdY2SbO7, the intensity of Bi3+ decreased with increasing Eu3+ concentration, indicating a potential energy transfer from Bi3+ to Eu3+. To examine the temperature sensitivity of the sample, its emission spectrum was investigated in the range of 300–500 K. Based on different temperature dependences of Bi3+ and Eu3+, the relative sensitivity (Sr) and absolute sensitivity (Sa) of the samples were calculated using the fluorescence intensity ratio (FIR) and thermochromic methods. In FIR modes, Sr based on IEu3+/IBi3+ reached 1.26% K−1 at 500 K, while Sr on double excitation method reached 1.36% K−1 at 340 K. In addition, according to the thermochromic properties of GdY2SbO7:Bi3+, Eu3+ phosphor, the temperature-sensing ability of the sample was investigated, and Sr reached a maximum value of 0.5996% K−1 at 300 K.

Keywords: Fluorescence intensity ratio, Thermally coupled levels, optical thermometry