The enhanced photoluminescence and temperature sensing performance in rare earth doped SrMoO4 phosphors by aliovalent doping: from material design to device applications

Abstract

Simultaneous enhancement of upconversion luminescence and temperature sensitivity is achieved by aliovalent doping in Er³⁺/Yb³⁺ codoped SrMoO₄ phosphors and a highly accurate ratiometric temperature sensing platform has been constructed in an all-fiber structure. The influence of aliovalent doping of Li⁺ and Ga³⁺ in SrMoO₄ phosphors on the crystal structure and growth was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). A detailed structural analysis was carried out using Eu³⁺ ions as a spectroscopic probe to disclose the change of the local site symmetry due to aliovalent doping. The upconversion emission intensity of Er³⁺ in SrMoO₄ phosphors is enhanced by 82 times and 255 times due to Li⁺ doping and Li⁺/Ga³⁺ codoping, respectively. The intense upconversion luminescence and high temperature sensitivity lead to a small temperature uncertainty (0.091 K) and an absolute error (−0.5–0.3 K) as well as good repeatability (<1%). Preliminary experiments from material design to device applications pave the way for the practical applications of ratiometric temperature sensors.