Tuning of the thermal quenching performance of Bi 3+ -doped scheelite Ca(Mo/W)O 4 solid solution phosphors.

The utilization of phosphor materials has always been a significant challenge in terms of improving thermal quenching performance. In this work, the thermal quenching performance tuning mechanism which establishes the band gap and thermal quenching correlation patterns is proposed. The crystal field splitting energy D q was decreased by changing the surrounding crystal lattice environment of Bi 3+ through a solid solution replacement, and the thermal quenching activation energy Δ E of Bi 3+ was tuned from 0.117 eV to 0.182 eV accordingly. At 423 K, the luminous intensity increases from 0.101 to 0.396 of the preliminary intensity at 303 K with increasing substitution. In addition, the band gap value of Bi 3+ calculated by diffuse reflectance spectroscopy increased from 4.40 eV to 4.72 eV, which corresponds to a linear positive correlation between the band gap and the thermal quenching properties. Furthermore, a monophase white-emitting phosphor with good thermal stability was prepared by constructing a Bi 3+ -Eu 3+ co-doping system. In particular, the relative sensitivity of S r for temperature measurement applications reached 3.17% K -1 based on the double-luminescence fluorescence intensity ratio. Thus, this modulation scheme can be used as a reference for the design of various phosphor materials with tunable thermal quenching properties in the future.