Temperature dependent luminescence of Dy3+ doped BaYF5 nanoparticles for optical thermometry

• Well-crystallized BaYF5:Dy3+ nanoparticles were successfully synthesized.
• Temperature dependent luminescence was obtained in a large temperature range.
• Two sets of emission bands of Dy3+ were analyzed using FIR method.
• The results imply the potential application of the material as thermal sensor.

Dy3+ doped BaYF5 nanoparticles with tetragonal structure were synthesized by hydrothermal method and solvothermal method. The structural and the luminescent properties of the samples were characterized by X-ray diffraction pattern, TEM and photoluminescence spectra. Emission of Dy3+ originated from 4I15/2 located at 450 nm and 4F9/2 located at 478 nm, 573 nm and 660 nm were observed under excitation of 355 nm laser. Behavior of fluorescence intensity ratio with temperature increasing from room temperature to approximately 800 K was investigated. And the optimum temperature range for thermometry is obtained to be 550–800 K according to its sensitivity-temperature relation, indicating the potential application of BaYF5:Dy3+ as a luminescent temperature sensor.