Color Control of the Mechanoluminescent Material Through a Combination of Color Centers

Abstract

We have synthesized the new organic mechanoluminescent material based on a 1,10-phenanthroline and an acetylacetone. The synthesized material shows both the photoluminescence and the mechanoluminescence with a green-color (main peak at 545 nm) by doping of a terbium (Tb). We have also investigated an effect of co-doping of Tb and europium (Eu) or dysprosium (Dy) on the luminescence property. Single doping gives a luminescence corresponding to each dopant with the main peak at 545, 612 or 573 nm for Tb, Eu or Dy, respectively, but the co-doping of Tb and Eu gives the luminescence corresponding to their doping amount ratio. As a result, the visual color can be controlled by the ratio. On the other hand, the co-doping of Tb and Dy keeps the luminescence corresponding to Tb single doping, but enhances its intensity. The results suggest that the electron transition process is different between the Tb-Eu and Tb-Dy co-doping. In the case of Tb/Eu co-doping, each dopant induced each own luminescence due to a significant difference in the electron energy state level between Tb and Eu. In contrary, the energy state of Dy becomes an extra electron supplier to Tb for the Tb/Dy co-doping. The results can expand application fields of the mechanoluminescence.