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

Abstract

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°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 SA value as well as its maximal value of 52.3 × 10−4 K−1 coupled with the SR of 46.3 × 10−4 K−1 at 413 K are gained and the SA 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.

Dual-Feedbacked Temperature Sensing of Er3+ in Fusiform-Polycrystalline-Implanted BaYF5/PAN Electrospun Fibers

“…Currently, the transition luminescence corresponding to the 2 H 11/2 and 4 S 3/2 thermal coupling energy levels as the main luminescence sources of Er 3+ ions has become a principal choice by the FIR technology since a high intensity of a green thermal fluorescence signal can be more easily captured by the detection equipment and more practical. − However, the narrow energy level interval hinders the improvement of relative sensitivity. In order to improve the overall sensitivity, the 4 G 11/2 and 2 H 9/2 thermal coupling energy levels with high dependence on excitation power and high sensitivity are utilized as an auxiliary temperature parameter to monitor accidental errors.…”

Upconversion Luminescence Properties and Temperature Sensing Characteristics of Tm3+, Yb3+-codoped SrAl2Si2O8 Phosphors with High Thermometric Sensitivities

“…SrAl 2 Si 2 O 8 belongs to both the feldspar structure and aluminosilicates, and the mineral provides a prototypical stable structure. 21 Aluminosilicates can be used as phosphor matrix materials due to their good physical and chemical stability, 22 thermal stability, high light conversion rate, low cost and easy synthesis under laboratory conditions. 23 Notably, the SrAl 2 Si 2 O 8 matrix was found to be an excellent UC matrix by Raman spectroscopy analysis with a relatively low phonon energy.…”