Control of NaAlSiO ₄:Eu ²⁺ photoluminescence properties by charge-compensated aliovalent element substitutions

We have conducted two kinds of the so-called charge-compensated aliovalent element substitutions to control the photoluminescence properties of NaAlSiO ₄:Eu ²⁺ with a special focus on the enhancement of the excitation intensity at 400 nm. The aliovalent element substitutions include cation-cation and cation-anion co-substitutions according to the general formulas Na _1-xM _xAl _1+xSi _1-xO ₄:Eu ²⁺ and Na _1-xM _xAlSiO _4-xN _x:Eu ²⁺ (M=Mg ²⁺, Ca ²⁺, and Sr ²⁺), respectively. The increase in the relative excitation intensity at 400 nm has been achieved in both types of the co-substitutions. Thus, the present research has demonstrated the effectiveness of the charge-compensated element substitution.