Tunable red-green-blue multicolor luminescence in Yb super(3+)/Tm super(3+)/Ho super(3+):Gd sub(3)Ga sub(5)O sub(12) nano-crystals

The Yb super(3+)/Tm super(3+)/Ho super(3+): Gd sub(3)Ga sub(5)O sub(12) nano-crystals have been successfully prepared via a citric acid complex procedure. The luminescence spectra were measured and the up-conversion processes were discussed. By means of adjusting the doping concentrations of Yb super(3+)/Tm super(3+)/Ho super(3+), the red-green-blue up-conversion luminescence changed obviously. Results indicated that the ratio of red-green-blue up-conversion emissions enhanced heavily with the increasing concentrations of Tm super(3+) doped in the Yb super(3+)/Tm super(3+)/Ho super(3+):Gd sub(3)Ga sub(5)O sub(12) nano-crystals, which was rooted in the three-photon resonant cross relaxation processes( super(1)G sub(4) (Tm) + super(5)I sub(7) (Ho) arrow right super(3)H sub(5) (Tm) + super(5)S sub(2) (Ho)). The tunable red-green-blue luminescence could be used in the fields of display, illumination, and photonics such as the white light generation.