Optical temperature-sensitive properties of CaMoO4: Eu3+ phosphors

In this study, CaMoO 4 : Eu 3+ phosphors with molar concentrations of 0.01 %, 0.03 %, and 0.1 % were synthesized via the hydrothermal process. The variable temperature PL spectra demonstrated a pronounced decline in the luminescence of MoO 4 2− with the temperature rising, suggestive of typical thermal quenching behavior, whereas the luminescence of Eu 3+ showcased an emerging trend characterized by an initial increase followed by a decline. This phenomenon was attributed to the intensified energy transfer effect from MoO 4 2− to Eu 3+ as the temperature increased. The thermal quenching trends between MoO 4 2− and Eu 3+ exhibited distinct differences, leading to the acquisition of high relative sensitivity when utilizing the FIR of MoO 4 2− and Eu 3+ for temperature sensing. It was found in the experiment that samples with higher Eu 3+ doping concentrations exhibited higher S r . In the CaMoO 4 : 0.1 % Eu 3+ sample, the S r-max reached 3.19 % K −1 at 303 K, which was an excellent value among inorganic materials. The findings of this paper indicate the potential application of CaMoO 4 : Eu 3+ phosphors for optical thermometry.