Thermodynamics and Kinetics Accounting for Antithermal Quenching of Luminescence in Sc₂(MoO₄)₃: Yb/Er: Perspective beyond Negative Thermal Expansion

Abstract

Defects are common in inorganic materials and not static upon annealing of the heat effect. Antithermal quenching of luminescence in phosphors may be ascribed to the migration of defects and/or ions, which has not been well-studied. Herein, we investigate the antithermal quenching mechanism of upconversion luminescence in Sc2(MoO4)3: 9%Yb1%Er with negative thermal expansion via a fresh perspective on thermodynamics and kinetics, concerning the thermally activated movement of defects and/or ions. Our results reveal a second-order phase transition taking place at ∼573 K induced by oxide-ion migration. The resulting variation of the thermodynamics and kinetics of the host lattice owing to the thermally induced oxide-ion movement contributes to a more suppressed nonradiative decay rate. The dynamic defects no longer act as quenching centers with regard to the time scale during which they stay nearby the Yb3+/Er3+ site in our proposed model. This research opens an avenue for understanding the antithermal quenching mechanism of luminescence via thermodynamics and kinetics.

Anti-thermal quenching of luminescence in Y2W3O12:Yb3+/RE3+ (RE = Er/Ho/Tm) and its temperature sensing application

“…Ye et al indicated that the thermally activated movement of defects and/or ions in the host contributed to a change in ET efficiency. 41 Huang et al also reported that the luminescence intensity of phosphor was influenced by the formation and amount of Frenkel defects at high temperatures. 24 They described the formation of the Frenkel defect based on the deviation of the partial WO 4 group is apt to deviate from the intrinsic to the interstitial site when the temperature increases.…”