Enhanced upconversion (UC) luminescence was obtained from a CaxYF3+2x host by doping with Yb3+/Er3+ or Yb3+/Tm3+. Lattice perturbation of YF3 by doping Ca2+ ions increased the energy transfer process between the absorbed Yb3+ ions and the activated Er3+ or Tm3+ ions, resulting in the emission of a bright multicolored UC luminescence.
