Er 3+,Yb 3+ co-doped CaWO 4 polycrystalline powders were prepared by a solid-state reaction and their up-conversion (UC) luminescence properties were investigated in detail. Under 980 nm laser excitation, CaWO 4: Er 3+,Yb 3+ powder exhibited green UC emission peaks at 530 and 550 nm, which were due to the transitions of Er 3+ ( 2H 11/2)→Er 3+ ( 4I 15/2) and Er 3+ ( 4S 3/2)→Er 3+ ( 4I 15/2), respectively. Effects of Li+ tri-doping into CaWO 4: Er 3+,Yb 3+ were investigated. The introduction of Li + ions reduced the optimum calcinations temperature about 100 °C by a liquid-phase sintering process and the UC emission intensity was remarkably enhanced by Li + ions, which could be attributed to the lowering of the symmetry of the crystal field around Er 3+ ions.
- CaWO : Er
- Li Tri-doping
- Solid-state Reaction Method
- UC (Up-conversion) Luminescence