Luminescence Properties and Energy Transfer in SrLa2Sc2O7 Co-Doped with Bi(3+)/M (M = Eu(3+), Mn(4+), or Yb(3+))

Series of Eu(3+)/Mn(4+)/Yb(3+)-doped SrLa(2)Sc(2)O(7):Bi(3+) (SLSO: Bi(3+)) were synthesized by a high-temperature solid-state method, and the energy transfer of Bi(3+)→Eu(3+)/Mn(4+)/Yb(3+) was observed. Under ultraviolet radiation, a 550 nm emission peak was observed, which is attributed to Bi(3+) occupying the Sr(2+)/La(3+) sites. Additionally, the other peaks were found to be 615, 707, and 980 nm, which are assigned to the Re(3+) (Eu(3+) and Yb(3+)) and Mn(4+) occupying two different cationic sites. An obvious energy transfer (ET) from Bi(3+) to Eu(3+)/Mn(4+)/Yb(3+) was observed, and the tunable color, emitting from yellow to red, was obtained; the ET efficiency was about 86.2%, 78.6%, and 27.5% in SLSO, respectively. We found that the large overlap area between the emission spectrum of the sensitizer and the excitation spectrum of the activator could produce efficient energy transfer, which provided the idea for designing experiments in the future for some highly efficient energy transfer processes.