Promising red phosphors LaNbO4:Eu3+, Bi3+ for LED solid-state lighting application

Abstract La 0.75 NbO 4 :Eu 3+ 0.25 and La 0.65 NbO 4 :Eu 3+ 0.25 , Bi 3+ 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 3+ , the charge transfer (CT) bands of Nb 5+ →O 2− and Eu 3+ →O 2− (−280 nm) weakened and a new and significant broad band Bi 3+ −O 2− (−330 nm) appeared, while the peaks at 395 and 466 nm assigned to f–f transitions of Eu 3+ was slightly changed. Compared with the commercial phosphor Y 2 O 2 S:0.05Eu 3+ , La 0.75 Nb 5 O 4 :Eu 3+ 0.25 and La 0.65 Nb 5 O 4 :Eu 3+ 0.25 , Bi 3+ 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 0.75 Nb 5 O 4 :Eu 3+ 0.25 and La 0.65 Nb 5 O 4 :Eu 3+ 0.25 , Bi 3+ 0.10 phosphors might be as promising red phosphors for near UV InGaN-based LED solid-state lighting application.