Optical temperature sensing properties of SnO2: Eu3+ microspheres prepared via the microwave assisted solvothermal process

Eu3+-activated SnO2 hollow microspheres were synthesized via a rapid microwave-assisted-solvothermal route within brief reaction duration of 10 min. The synthesis process was optimized via regulating the microwave power which accelerated the nucleation process along with the elevation of crystal growth. Microscopic analysis revealed the formation of hollow microspheres consisting of tiny SnO2 nanoparticles on the surface. The photoluminescence of SnO2:Eu3+ exhibited a broad band from 400 to 575 nm due to the host and dopant emissions. The emission intensity of SnO2:Eu3+ increased gradually with the increase of the Eu3+ concentration up to 0.75 mol%, and then diminished by the formation of Eu2Sn2O7 phase. The fluorescence intensity ratio (FIR) between the emissions of Eu3+ ions and host were measured by varying temperatures to obtain the sensing performance of materials and the maximum relative-sensitivity was calculated as 1.83% K-1. This research indicated the suitability of SnO2:Eu3+ hollow microspheres for phosphor thermometry.