Special Tm3+ transition and white upconversion luminescence in the Yb3+/Tm3+ co-doped KMnF3

Special Tm3+ transition and a bright green light emission is first observed in the Yb3+/Tm3+ co-doped KMnF3, which are synthesized by the molten salt synthesis method. The RGB light emissions are simultaneously obtained with a single Tm3+ activator, and white upconversion luminescence is observed only by changing the reaction time.