Synthesis and luminescent properties of Zn0.890Nb2O6:Eu0.053+, Bi0.0053+, M0.055+ (M = Li, Na, K) phosphors

Abstract Zn 1– x Nb 2 O 6 : Eu x 3 + , Zn 0.95− y Nb 2 O 6 : Eu 0.05 3 + , Bi y 3 + , and Zn 0.890 Nb 2 O 6 : Eu 0.05 3 + , Bi 0.005 3 + , M 0.055 + (M = Li, Na, K) red-emitting phosphors were synthesized via sol–gel method. X-ray power diffraction, scanning electron microscopy, photoluminescence excitation, and emission spectra (PL) were used to characterize the phosphors. The obtained Zn 1− x Nb 2 O 6 : Eu x 3 + phosphor showed a stronger excitation band near 400 nm. When Eu 3+ and Bi 3+ were incorporated into the ZnNb 2 O 6 lattice, a broad band from 300 nm to 350 nm with the center at 329 nm appeared. Taking the ion size difference of Li + (59 pm), Na + (99 pm), K + (137 pm), Eu 3+ (95 pm), and Zn 2+ (60 pm), the emitting intensity of the phosphor increased observably by adding Li + and Na + as charge compensators. The PL intensity of the K + -doped in Zn 0.945 Nb 2 O 6 : Eu 0.05 3 + , Bi 0.005 3 + was slightly less than those of Zn 0.945 Nb 2 O 6 : Eu 0.05 3 + , Bi 0.005 3 + . The chromaticity coordinates of Zn 0.890 Nb 2 O 6 : Eu 0 . 05 3 + , Bi 0 . 005 3 + , Li 0 . 055 + ( x  = 0.67, y  = 0.34) were close to the standard of National Television Standard Committee values ( x  = 0.670, y  = 0.330). The fabricated light-emitting diode (LED) further confirmed that the Zn 0.890 Nb 2 O 6 : Eu 0 . 05 3 + , Bi 0 . 005 3 + , Li 0 . 055 + phosphors can efficiently absorb up to 400 nm irradiation and emit red light, and are potential candidates as red-emitting components for white LED.