Upconversion luminescence properties of the novel garnet structure Ca2LaZr2Ga3O12:Yb3+,Er3+/Tm3+ phosphors

Yb3+–Er3+ and Yb3+–Tm3+ activated novel garnet structure Ca2LaZr2Ga3O12 phosphors were synthesized by solid state reaction and its upconversion luminescence properties were investigated. X-ray diffraction patterns confirmed the synthesized samples were indexed to the garnet structure. The upconversion emission spectra revealed that under 980 nm laser excitation, bright green and blue light had been achieved in Ca2LaZr2Ga3O12:Yb3+,Er3+ and Ca2LaZr2Ga3O12:Yb3+,Tm3+ phosphors, respectively. Yb3+ acted as sensitizers in the upconversion process and did not show its characteristic emission peak. Strong Er3+ and Tm3+ emission peaks were obtained via energy transfer from Yb3+. The possible energy transfer processes of Yb3+ to Er3+ and Tm3+ were discussed. The results indicated that Yb3+–Er3+ and Yb3+–Tm3+ activated Ca2LaZr2Ga3O12 phosphors exhibited excellent upconversion luminescence properties.