Red persistent luminescent silicate nanoparticles

Abstract

Red persistent luminescent diopside nanoparticles doped with Mn(2+) and codoped with RE(3+) (Eu(2+), Dy(3+)) have been obtained by sol-gel method.The influence of codoping rare earth ions on the persistent luminescence was studied by wavelength-resolved thermally stimulated luminescence (TSL) measurements from 30 to 650 K after X-ray irradiation. From these first results, a mechanism of persistent luminescence is proposed.In this mechanism Mn(2+) and Eu(2+) act as TSL recombination centers, Mn(3+) and Eu(3+) being stable hole centers, whereas Dy(3+) acts as a good electron trap giving rise to a TSL peak at high temperature. Finally, persistent luminescence was measured. Intensity and persistence of the red luminescence of CaMgSi(2)O(6): Mn(2+)-Dy(3+) are better than those of CaMgSi(2)O(6): Mn(2+) and CaMgSi(2)O(6): Mn(2+)-Eu(2+), which are in agreement with the results of TSL.