Stark sublevels investigation in Y2WO6:Tm3+-Yb3+ phosphor for thermometry and internal temperature measurement

Abstract

Intensity ratio investigation in the Y2WO6:Tm3+-Yb3+ phosphors synthesized by solid state reaction method has been discussed first time under 980 nm laser diode excitation with the help of multiple peak fitting. The temperature dependent upconversion emission study has been performed for optical temperature sensing by using stark sublevels of 1G4 level of Tm3+ ion. The intensity of the two stark sublevels is varied due to the thermalization under the application of external temperature. The energy gap has been calculated about ∼427 cm−1 of the two stark sublevels via Boltzmann’s population distribution law. The calculated sensitivity (maximum about ∼34 × 10−4 K−1 at 303 K) and optical heating properties prove the utility of the prepared phosphor in making optical temperature sensing probe and optical heater.