Gd3+ ion induced UV upconversion emission and temperature sensing in Tm3+/Yb3+:Y2O3 phosphor

Cubic phase Tm3+/Yb3+:Y2O3 and Tm3+/Yb3+/Gd3+:Y2O3 phosphors were prepared by low temperature combustion technique for upconversion emission in UV-visible range. The 980 nm excitation has generated UV emission at 314 nm in tridoped phosphor due to the energy transfer from Tm3+ to Gd3+ ion. Characteristic emission bands from Tm3+ are also observed in both the phosphors. Thermally coupled Stark sublevels (1)G(4(a)) (476 nm) and (1)G(4(b)) (488 nm) of Tm3+ ion were utilised for optical thermometry using fluorescent intensity ratio (FIR) method. The result shows that maximum absolute sensitivity in tridoped phosphor is observed to be 1.33 x 10(-3) K-1 at 298 K. Moreover, temperature rise of phosphor at various pump power densities was also measured and it is estimated to achieve 407 K at the pump power density of 38.46 W/cm(2).0 2022 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

Cubic phase Tm3+/Yb3+:Y2O3 and Tm3+/Yb3+/Gd3+:Y2O3 phosphors prepared by low temperature combustion technique exhibit upconversion emission in the UV-visible range. The phosphors show characteristic emission bands from Tm3+ ions and enable optical thermometry using specific Stark sublevels. The maximum absolute sensitivity of the tridoped phosphor at 298 K is 1.33 x 10(-3) K-1.