Tunable white upconversion luminescence from Yb3+-Tm3+-Mn2+ tri-doped perovskite nanocrystals

Tunable broadband white upconversion (UC) luminescence has been demonstrated in Yb3+/Tm3+/Mn2+ tri-doped KZnF3 nanocrystals from the excitation of a 976 nm laser diode (LD). The white light is composed of three sharp band peaks at 480, 650 and 700 nm, originating from the UC emissions of Tm3+ ions, and one broad band centered at 585 nm, originating from exchange-coupled Yb3+–Mn2+ dimers. The effects of the concentration, pump power and temperature on the UC luminescence properties of KZnF3:Yb3+,Tm3+,Mn2+ nanocrystals have been investigated. By changing the Mn2+/Tm3+ content ratio, various colors of the UC luminescence can be easily obtained in KZnF3:Yb3+,Tm3+,Mn2+ nanocrystals, which gives these nanocrystals potential applications in the fields of lighting, displays and lasers.