Luminescence Dependence of Pr3+ Activated SiO2 Nanophosphor on Pr3+ Concentration, Temperature, and ZnO Incorporation

Green-emitting ZnO nanoparticles were successfully embedded in Pr 3+ -doped SiO 2 by a sol–gel method resulting in a red-emitting ZnO·SiO 2:Pr 3+ nanocomposite phosphor. The particle morphology and luminescent properties of SiO 2:Pr 3+ phosphor powders, with or without ZnO nanoparticles, were, respectively, investigated by electron microscopy and luminescence spectroscopy. Luminescence of SiO 2:Pr 3+ was studied as a function of different Pr 3+ concentrations and temperature. Both Pr 3+ concentration and temperature were found to influence the 1 D 2 emission from Pr 3+ strongly. Defects emission from ZnO nanoparticles was measured at 517 nm compared with the normal peak at 470 nm from micrometer-sized ZnO powders. Only red emission at 614 nm from Pr 3+ ions in SiO 2:Pr 3+ and ZnO·SiO 2:Pr 3+ was observed. The green emission from ZnO in ZnO·SiO 2:Pr 3+ was quenched, and the red emission from Pr 3+ was doubly enhanced compared with SiO 2:Pr 3+ . The enhancement of the PL intensity from SiO 2:Pr 3+ with ZnO incorporation denotes the presence of energy transfer from ZnO to Pr 3+ ions.