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

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.