Dual mode emissions with enhanced green up-conversion luminescence by Gd3+ doping and down-conversion from Eu3+ in NaMnF3:Yb, Er@NaGdF4:Eu. Issue 29 (9th July 2021) - Liu, Wenjing
Abstract : NaMnF3 :Yb, Er shows single band red emissions of Er 3+ at 980 nm, while NaMnF3 :Yb, Er@NaGdF4 :Eu shows green up-conversion emission due to the presence of Gd 3+, and red down-conversion emission of Eu 3+ . Abstract : NaMnF3 :Yb, Er and NaMnF3 :Yb, Er@NaGdF4 : x Eu ( x = 0, 0.3, 0.6, and 0.9) samples were synthesized by a simple hydrothermal method. The as-obtained NaMnF3 :Yb, Er particles show a single red emission under the irradiation of infrared light (980 nm), due to the energy exchange transfer process between Mn 2+ ions and Er 3+ ions. Notably, further growth of NaGdF4 :Eu on the basis of NaMnF3 :Yb, Er enhanced the green up-conversion luminescence of Er 3+ ions, which gradually shifted from red to green with the increase of the Gd 3+ ion doping amount. In addition, NaMnF3 :Yb, Er@NaGdF4 :Eu exhibits red color under ultraviolet excitation (397 nm). These results provide a possible means for controlling the luminescence properties of the lanthanide doped up-conversion system. The luminescent film synthesized with NaMnF3 :Yb, Er@NaGdF4 :Eu can show different luminescent colors under different light irradiation (near infrared and ultraviolet), which indicates that they have potential applications in multi-mode anti-counterfeiting.