Au@SiO2 hybridized Ca2B2O5·H2O:Tb3+ nano belts: An insight on the enhanced photoluminescence by Au nanoparticles

The photoluminescence (PL) properties of Ca2B2O5·H2O:Tb3+ nanobelts are enhanced by Au nanoparticles by coupling the surface plasmon waves of Au with radiative modes of the phosphor. To investigate the PL properties of the hybridization, the distance between the Au nanoparticles and the phosphors are adjusted by SiO2 nanolayer, and a layer with 6 nm in thickness was found to have the highest enhancement factor of 4.88. The quenching effect of Au nanoparticles on the PL has also been investigated without SiO2 layer. These experiments demonstrate the competing effect between PL enhancement and the quenching effect of Au nanoparticles, and the enhancement mechanism is ascribed to the photons emitted from surface plasmon inducing by the light emission of Tb3+ ions in Ca2B2O5·H2O nanobelts, or by enhancing the absorption ability. These results are valuable reference for enhancing the PL of inorganic phosphors.