White luminescence and energy transfer process in Bi3+,Sm3+ co-doped Ca3Al2O6 phosphors

• Energy transfer from Bi3+ to Sm3+ in Ca3Al2O6 was systemically investigated.
• Ca3Al2O6:Bi3+,Sm3+ generates varied hues from blue green to orange white.
• Our work extends the understanding of interactions between Bi3+ and Sm3+.

Ca3Al2O6:Bi3+,Sm3+ phosphors were synthesized by conventional solid state reaction method and their luminescent properties were systemically investigated by excitation, emission spectra and decay curves measurement. Through an efficient energy transfer process from Bi3+ to Sm3+, the obtained phosphors exhibit emission from Bi3+ and Sm3+ with considerable intensity under near-ultraviolet excitation (300 nm). Tuning the content of Sm3+ can generate the varied hues from blue green to white. Our research will extend the understanding of interactions between Bi3+ and rare earth ions and show the potential application of Bi3+,Sm3+ co-doped phosphors in W-LEDs field.

(a) Emission spectra (λex = 300 nm) of CAO:Bi(3%),Sm(y%) and CAO:Sm(3%) phosphors. (b) Excitation spectra (λem = 603 nm) of CAO:Bi(3%), Sm(y%) phosphors and CAO:Sm(3%). (c) Decay curves of Bi3+ emission (λex = 300 nm, λem = 488 nm) in CAO:Bi(3%), Sm(y%) phosphors (annotate: the curves in (a) (b) and (c) are labeled in the same legend). (d) Energy-level diagram of Bi3+ and Sm3+ ions and energy transfer process.Figure optionsDownload high-quality image (229 K)Download as PowerPoint slide