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Currently, the unique 5D 4 energy level of terbium (Tb3+) can contribute to narrow-band green light emission, which has high application prospects. However, due to its poor thermal stability at high temperatures, how to enhance the antithermal-quenching properties of Tb-doped phosphors has become a research difficulty in the field of solid-state lighting and temperature sensing. In this contribution, the antithermal-quenching green-emitting of terbium was achieved by Nb/Ta substitution to form GdNb 1-x Ta x O 4 :Tb3+ phosphors with various components. Photoluminescence analyses reveal an increasing trend in both the optical band gap and the intervalence charge transfer (IVCT) energy level positions with substitution. Variable-temperature spectrums observed that the phosphors under different compositions presented a large discrepancy in thermal quenching performance. It is elucidated that the elevated position of the IVCT energy level (IVCT-EL) predominantly influences thermal quenching, bolstering its role as a compensatory luminescence channel of 5D 3 →5D 4 far more than functioning as a quenching luminescence channel for Tb3+5D 3 /5D 4. Delving into the perspective of IVCT-EL positioning unveils the intrinsic mechanism through which IVCT-EL positions modulate the thermal quenching properties of phosphors with varying compositions due to the substitution of Ta for Nb. This insight facilitates the realization of enhanced thermal quenching resistance in phosphors. Furthermore, the antithermal-quenching property of Tb3+ in single-phase phosphors can be effectively modulated by excitation at different wavelengths. This tuning scheme not only advances the exploration of terbium-doped antithermal-quenching phosphors but also provides a novel strategy and reference for designing green-emitting phosphors in the fields of lighting and sensing. [Display omitted] [ABSTRACT FROM AUTHOR]

• Designed dual-activators in double perovskite according to site-beneficial occupation principle. • Perovskite La 3 Li 3 W 2 O 12 matrix contains abundant sites that suitable the doping of Mn4+ and Lanthanide. • Taking advantage of diverse thermal quenching between Mn4+ and Eu3+ ions for optical thermometry. Currently, Eu3+ or Mn4+ activated red-emitting fluorescent materials are widely used for solid-state lighting and optical temperature sensing. Here, we have chosen an abundant double perovskite structure that provides not only a trivalent Eu3+ lattice but also a tetravalent Mn4+ lattice and guarantees simultaneous emission. A family of rare earth (Eu3+) and transition metal (Mn4+) co-doped La 3 Li 3 W 2 O 12 (LLWO) red-emitting phosphors were obtained by designing a site-occupation strategy. By changing the concentration of Eu3+, the coordination environment of the activator is adjusted to finally achieve the adjustable emission of the phosphor from orange to red. In addition, when the doping concentration of Eu3+ is greater than 0.05, the symmetry of the doping sites in the perovskite structure decreases leading to the luminescence performance of red color and the enhancement of luminescence intensity. Finally, optical thermometry based on fluorescence intensity ratio shows that the developed phosphor has high sensitivity. [Display omitted] [ABSTRACT FROM AUTHOR]