Synthesis and luminescence properties of novel red-emitting R3P4O13:Bi2+ (R = Sr and Ba) phosphors

Novel red phosphors R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) are synthesized by solid state reaction method in air, and their crystal structures and fluorescence properties are characterized. The excitation bands peaking at ∼440 nm match with the blue LED chip, and their red emission band peaking at ∼658 and 686 nm within the range 580–800 nm owing to 2 P 3/2 (1) →  2 P 1/2 the transition of Bi 2+ ions can be observed, respectively. The relation between Bi 2+ doping concentration and emission intensity is discussed and the optimal Bi 2+ ion doping concentration is ∼3.0 mol%. Decay curves and time-resolved spectra confirm that R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) phosphors have only single Bi 2+ center. The luminous mechanism is explained by energy level diagram of Bi 2+ . The luminescence properties indicate that R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) phosphors have a potential to be used as red emitting phosphor candidate for white LEDs based on ∼440 nm blue LED chip.