Promising red phosphors LaNbO sub(4):Eu super(3+), Bi super(3+) for LED solid-state lighting application

La sub(0.75)NbO sub(4):Eu super(3+) sub(0.25) and La sub(0.65)NbO sub(4):Eu super(3+) sub(0.25), Bi super(3+) sub(0.10) phosphors were synthesized by solid-state reaction method, and their photoluminescence properties were discussed in detail. With the increased incorporation of the co-activator Bi super(3+), the charge transfer (CT) bands of Nb super(5+)-->O super(2-) and Eu super(3+)-->O super(2-) (-280 nm) weakened and a new and significant broad band Bi super(3+)-O super(2-)(-330 nm) appeared, while the peaks at 395 and 466 nm assigned to f-f transitions of Eu super(3+) was slightly changed. Compared with the commercial phosphor Y sub(2)O sub(2)S:0.05Eu super(3+), La sub(0.75)Nb sub(5)O sub(4):Eu super(3+) sub(0.25) and La sub(0.65)Nb sub(5)O sub(4):Eu super(3+) sub(0.25), Bi super(3+) sub(0.10) phosphors emit brighter red light at 615 nm with line spectra upon the excitation of near UV light (395 nm) and exhibited the Commission International d'Eclairage (CIE) chromaticity coordinates (x=0.658, y=0.342) and (x=0.657, y=0.342) that are closer to the standard of national television standard committee (NTSC). The results showed that La sub(0.75)Nb sub(5)O sub(4):Eu super(3+) sub(0.25) and La sub(0.65)Nb sub(5)O sub(4):Eu super(3+) sub(0.25), Bi super(3+) sub(0.10) phosphors might be as promising red phosphors for near UV InGaN-based LED solid-state lighting application.