Color-tunable photoluminescence and energy transfer of (Tb1?xMnx)3Al2(Al1?xSix)3O12:Ce3+ solid solutions for white light emitting diodes

摘要

(Tb _(1? x ) Mn _( x ) ) _(3) Al _(2) (Al _(1? x ) Si _( x ) ) _(3) O _(12) :Ce ~(3+) solid solution phosphors were synthesized by introducing the isostructural Mn _(3) Al _(2) (SiO _(4) ) _(3) (MAS) into Tb _(3) Al _(5) O _(12) :Ce ~(3+) (TbAG). Under 456 nm excitation, (Tb _(1? x ) Mn _( x ) ) _(3) Al _(2) (Al _(1? x ) Si _( x ) ) _(3) O _(12) :Ce ~(3+) shows energy transfers (ET) in the host, which can be obtained from the red emission components to enhance color rendering. Moreover, (Tb _(1? x ) Mn _( x ) ) _(3) Al _(2) (Al _(1? x ) Si _( x ) ) _(3) O _(12) :Ce ~(3+) ( x = 0–0.2) exhibits substantial spectral broadening (68 → 86 nm) due to the 5d → 4f transition of Ce ~(3+) and the ~(4) T _(1) → ~(6) A _(1) transition of Mn ~(2+) . The efficiency of energy transfer ( η _(T) , Ce ~(3+) → Mn ~(2+) ) gradually increases with increasing Mn ~(2+) content, and the value reach approximately 32% at x = 0.2. Namely, the different characteristics of luminescence evolution based on the effect of structural variation by substituting the (MnSi) ~(6+) pair for the larger (TbAl) ~(6+) pair. Therefore, with structural evolution, the luminescence of the solid solution phosphors could be tuned from yellow to orange-red, tunable by increasing the content of MAS for the applications of white light emitting diodes (wLED).