The Luminescence Kinetics of Al2O3–Ce:YAG Ceramic Phosphors: Application of SR for Correct Investigations

The luminescence kinetics of $\mathbf{A l}_{2} \mathrm{O}_{3}-\mathrm{Ce}: Y A G$ composite ceramics with $0.05-0.3 \mathrm{at} \% \mathrm{Ce}^{3+}$ doping has been investigated in this paper. Using synchrotron radiation with an initial pulse duration of 1 ns and a fitting model in the form of temporal convolution of the initial pulse with the decay exponent allowed us to identify two modes in the decay process. For the fast mode a time constant is growing from $\sim 1-1.5$ up to $\sim 3 \mathrm{~ns}$ and its fraction is decreasing from $\sim 20-40 \%$ down to $\sim 13-14 \%$ while Ce concentration is increasing from 0.05 up to $0.3 \mathrm{at} \%$. Among the literature data, one can find both contradictory to the results obtained and supporting them. Comparison with studies of thermal quenching in $\mathrm{Ce}^{3+}$-doped phosphors suggests an effective equivalence between the effects of SR and elevated temperatures on luminescence kinetics. Confirmation of the hypothesis requires additional studies on the effect of dose load from SR on the parameters of luminescence kinetics.