Fig. 2: Analysis of the valence state, steady-state and transient photoluminescence characteristics were conducted.

a–c This includes XANES spectra, a high-resolution XPS spectrum for Mn-2p, and EPR spectra recorded at 77 K, all specific to Mn within the sample of YAG doped with 2%Ce³⁺ and 20%Mn²⁺; d Additionally, PLE and PL spectra were obtained for YAG doped with 2% Ce³⁺, YAG doped with 20%Mn²⁺, and YAG co-doped with both 2%Ce³⁺ and 20%Mn²⁺; e PL spectra were also recorded for YAG doped with 2%Ce³⁺ and varying concentrations of Mn²⁺ (ranging from x = 2% to 16%); f, g Furthermore, the fluorescence decay curves of Mn²⁺ in YAG doped with 2% Ce³⁺ and varying concentrations of Mn²⁺ (x = 2% to 20%) upon pulsed 450 nm excitation, monitored at 600 nm and 750 nm, are presented. Detailed fitting equations and parameters for these decay curves are outlined in Tables S2–S4