Efficient Luminescence Enhancement of Mg2TiO4:Mn4+ Red Phosphor by Incorporating Plasmonic Ag@SiO2 Nanoparticles.

One of prospective ways for boosting efficiency of luminescent materials is their combination with noble metal nanoparticles. Collective, so-called plasmon, oscillations of surface electrons in a nanoparticle can resonantly interact with incident or fluorescent light and cause an increase in the light absorption cross section or radiative rate for an adjacent emitter. Plasmonic inorganic phosphors require gentle host crystallization at which added noble nanoparticles will not suffer from aggregation or oxidation. The prospective plasmonic Mg2TiO4:Mn4+ phosphor containing core@shell Ag@SiO2 nanoparticles is prepared here by spare low-temperature annealing of a sol-gel host precursor. It is revealed that Mn4+ luminescence nonmonotonously depends on the size and concentration of 40 and 70 nm silver nanoparticles. It is demonstrated that luminescence of the Mg2TiO4:Mn4+ phosphor can be up to a 1.5 times increase when Mn4+ excitation is supported by localized surface plasmon resonance in Ag@SiO2 nanoparticles.