Two-Step Synthesis, Upconversion Properties and Temperature Sensing Behavior of CaTiSiO5:Er3+/Yb3+ Phosphors

Oxide upconversion (UC) materials show great potential for temperature detection application due to its excellent thermostability. The CaTiSiO5 (CTS) host with excellent physicochemical properties is difficult to be prepared owing to the emergence of stable CaTiO3 phase. Herein, we focus on the synthesis of pure CTS phase and the investigation of UC properties of Er3+ and Er3+ - Yb3+ doped CTS phosphors. Three diverse routes are adopted toward the synthesis of pure CTS phase, which demonstrates that shielding the Ca2+ in crystal lattice is vital for achieving this target. The optimal calcined temperature at 1270 degrees C is confirmed by XRD, morphology change and EDX results. UC properties of color-emitting, optimal Er3+/Yb3+ concentrations as well as temperature behavior are revealed. The CTS:1%Er3+/1%Yb3+ phosphor with bright green and red emissions is obtained and low Er3+/Yb3+ dopant concentrations are caused by the unequal substitutions between Er3+/Yb3+ and Ca2+ ions. High S-A value as well as its maximal value of 52.3 x 10(-4) K-1 coupled with the S-R of 46.3 x 10(-4) K-1 at 413 K are gained and the S-A value with small fluctuation were achieved in the CTS:1%Er3+/1%Yb3+ sample. These results suggest that the CTS:1%Er3+/1%Yb3+ may be a candidate for temperature detection application. (C) 2019 The Electrochemical Society.