Research Article

Suppressing Self‐Oxidation of Eu²⁺ in Li₂CaSiO₄ for Full‐Spectrum Lighting and Accurate Temperature Sensing

Eu²⁺‐doped phosphors have attracted the great attention of researchers in the past decade. However, Eu²⁺ dopant in inorganic hosts often suffers from the self‐oxidation effect, therefore causing the attenuated emission intensity and quantum efficiency. In this regard, developing Eu²⁺ doped phosphors with the prohibited self‐oxidation effect of Eu²⁺ and increased thermal stability is urgently required. Herein, an innovative cyan‐light emitting Li₂CaSiO₄:Eu²⁺/Eu³⁺, Lu³⁺ (LCSO) phosphor is designed. Both experimental results and theoretical calculations demonstrate that adding Lu³⁺ restricts the self‐oxidation of Eu²⁺ into Eu³⁺, thus improving the emission of Eu²⁺. Meanwhile, the Lu³⁺ introduction brings out excellent thermal stability. Finally, an efficient WLED with a color temperature (CCT) of 4573 K and a high color rendering index (R_a) of 84.2 is obtained using the as‐prepared phosphor due to the perfect compensation of the cyan light. As the introduction of Lu³⁺ improves the stability of Eu²⁺, a much greater difference in PL decay rate between Eu²⁺ and Eu³⁺ in LCSO is reached, thereby improving their sensitivity in temperature sensing. The strategy of Lu³⁺ introduction for prohibiting the self‐oxidation of Eu²⁺ for efficient and stable Eu²⁺ emission may stimulate some new ideas in designing high‐performance phosphors for more diverse applications.