Novel orange-yellow-green color-tunable Bi3+-doped Ba3Y4−wLuwO9 (0 ≤ w ≤ 4) luminescent materials: site migration and photoluminescence control†
A novel orange-yellow-emitting Ba3Y4O9:Bi3+ phosphor (550 nm) has been firstly discovered. Meanwhile, we report isomorphic Ba3Lu4O9:Bi3+ with green emission (526 nm). Based on the cation substitution strategy, a series of Ba3Y4−wLuwO9:Bi3+ (0 ≤ w ≤ 4) solid solution phases are successfully constructed, realizing consecutive photoluminescence control from orange-yellow to green light. The occurrence of site migration of Bi3+ ions from Y2/Lu2 and Y4/Lu4 to Y1/Lu1 and Y3/Lu3 sites results in the blueshift of Ba3Y4−wLuwO9:Bi3+ (0 ≤ w ≤ 4), which is confirmed by the linear increase of PL intensity I(1+3)/I(2+4) with the substitution of Lu3+ ions for Y3+ ions. Besides, the improved thermal stability of Ba3Y4−wLuwO9:Bi3+ (0 ≤ w ≤ 4) with the substitution of Lu3+ for Y3+ originates from the better structure rigidity. The fabricated white light-emitting diodes (WLEDs) exhibit excellent warm white light, indicating that the as-prepared Ba3Y4−wLuwO9:Bi3+ (0 ≤ w ≤ 4) phosphors can act as a green to yellow emitting component in WLED lighting.