Luminescence and energy transfer in phosphor LiAl5O8: Ce3+, Dy3+

Ce3+ and Dy3+-doped LiAl5O8 were synthesized in the present study. The luminescence properties of Ce3+ and Dy3+, and the energy transfer from Ce3+ to Dy3+ were investigated. The Ce3+ species in LiAl5O8 emit one broad band that peaks at 351 nm under the excitation of ultraviolet light, which is attributed to the 5d–4f transitions of Ce3+. The luminescence of Dy3+ in singly doped LiAl5O8 can not be detected due to its low oscillator strength. However, Dy3+ emit intense blue (477 nm) and yellow (569 nm) light after the introduction of Ce3+. This phenomenon demonstrates that there exists effective energy transfer from Ce3+ to Dy3+, which occurs because the emission spectrum of Ce3+ perfectly overlays the excitation spectrum of Dy3+. The energy transfer from Ce3+ to Dy3+ is performed through dipole–dipole interactions. The experimental results show that LiAl5O8 co-doped with Ce3+ and Dy3+ can be a potential two-band (blue and yellow) phosphor.

► Luminescence of Dy3+ in LiAl5O8 obtains obvious enhancement by Ce3+ co-doping.
► Effective energy transfer from Ce3+ to Dy3+ in LiAl5O8 was validated.
► The reason and mechanism of energy transfer from Ce3+ to Dy3+ were analyzed in detail.
► Ce3+ and Dy3+ co-doped LiAl5O8 can be a potential two-band (blue and yellow) phosphor.