Achieving the multi-color tunable luminescence and application of Ce3+-activated Mg2SiO4 through the carbon and hydrogen co-reduction

The development of simple and effective strategies to regulate and optimize the luminescent properties of Ce 3+ in phosphors is both crucial and highly challenging. Herein, we propose a simple C + H 2 co-reduction strategy using graphite crucibles to achieve tunable luminescence of Ce 3+ at the Mg sites in Mg 2 SiO 4 . When the sample is synthesized under H 2 reduction alone, Ce 3+ preferentially occupies the Mg(1) position in Mg 2 SiO 4 and produces blue-violet emission. While the sample is synthesized under C + H 2 co-reduction, Ce 3+ can occupy the Mg(2) position giving rise to a yellow-green emission and producing broad-spectrum luminescence. Particularly, under 365 nm excitation, the Ce 3+ occupying the Mg(2) site can achieve ultra-broadband emission with a full width at half maximum reaching 232 nm. By co-doping Zn 2+ , Mg 2 SiO 4 :Ce 3+ ,Zn 2+ not only exhibits good thermal stability (retaining 48% of its initial intensity at 423 K), but also shows a high color rendering index (Ra = 95.3) when combined with commercial red fluorescent powder (Sr,Ca)AlSiN 3 :Eu 2+ . This work is expected to be effectively applied in lighting and anti-counterfeiting, and it provides a new approach for activating hidden crystallographic sites to achieve multi-functional applications.