A deep-red-emitting Bi3+/Mn4+-doped CaLi6La2Nb2O12 phosphor: Luminescence and energy transfer properties

Recently, much attention has been attracted on the optical properties based on the phosphors for LED light. A near Ultraviolet (n-UV) and blue chip activated phosphor of CaLi6La2Nb2O12:Bi3+, Mn4+ is synthesized by a traditional SSR method. Phase purity and lattice structure of the crystal have been confirmed and investigated by XRD, Rietveld refinement, FE-SEM and TEM. The luminescence performances of the series phosphors are investigated by diffuse reflection spectra (DR), Raman scattering spectra, steady-state PL spectra and the measurement of lifetime., the CaLi6La2Nb2O12:Bi3+, Mn4+ exhibits emission peaked at similar to 466 and similar to 711 nm Under excited at 312 nm. The Dq, B and C are calculated to estimate the nephelauxetic effect of Mn4+ in [Nb06) octahedral lattice. The coordinate shifting could be controllable through the energy transfer Bi3+ -> Mn4+, which can be verified by PL spectra and decay lifetimes. Finally, by coating the blend of red CaLi6La2Nb2O12:0.03Bi(3+)0.015 Mn4+ and Y3Al5O12:Ce3+ (YAG:Ce3+) phosphors onto the blue LED chip, a LED device with good performances (x = 0.36, y = 0.36, CRI = 86.6, CCT = 4220 K) can be achieved. Hence, CaLi6La2Nb2O12:Bi3+, Mn4+ is a good material of red emission.