Upconversion emissions of the NaMgF3: Tm3+, Yb3+ submicron particles and the emission modulation by the Mn2+ ions in the visible range

With the excitation of a 978 nm laser, upconversion emission of the NaMgF 3 : Tm 3+ , Yb 3+ , Mn 2+ submicron particles include two red emission bands located at 648 and 698 nm and a green emission at about 510 nm in the visible range. The experimental results confirm that the Mn 2+ ions play the key role in the emission modulation between the 648 nm and 698 nm. The incident laser power dependence confirms that the emission at 648 nm is completely different from the emissions at 698 nm, and more than 3 photons are involved in the emission at 648 nm. With the doping of Mn 2+ ions, the intensity ratio R 1 / R 2 of the emission at 648 nm and 698 nm increases first, and decreases for the Mn 2+ concentration larger than 2%. The incident laser power and laser pulse-width also have evident modulation effect of the UC emissions. All the Mn 2+ related phenomena are due to the energy transfer paths ET5 and ET6 between the Tm 3+ and Mn 2+ ions. Graphical abstract