Enhanced green up-conversion luminescence in In2O3:Yb3+/Er3+ by tri-doping Zn2+

By co-doping Yb3+/Er3+ into ordinary material In2O3, the up-conversion glow behavior will be triggered up. On this basis, the luminescence intensity can be significantly improved by tri-doping Zn2+ ions. Compared with In2O3:Yb3+/Er3+, the luminescence intensity of In2O3:Yb3+/Er3+/Zn2+ is significantly enhanced and the emitting light changes from faint red to bright green. This can be attributed to the reduction of site symmetry of the luminescence center and the promotion of crystallinity because of lattice distortion caused by Zn2+ ions. The up-conversion luminescence of the In2O3:Yb3+/Er3+/Zn2+ in the red and green light regions are two-photon excitation process, and the quantum yield (QY) is calculated to be 0.1%. The luminescence at the 524 nm emission peak corresponds to the transition Er3+:2H11/2 → 4I15/2. Other two emission peaks in green area (550 nm, 564 nm) correspond to the transition Er3+:4S3/2 → 4I15/2. And the emission peaks in red area (659 nm, 683 nm) root in the transition Er3+:4F9/2 → 4I15/2.