Enhanced photoluminescence from SiOx–Au nanostructures

Abstract

Highly efficient photoluminescence (PL) emission is obtained from flower-like silicon oxide (SiO_x)–Au nanostructures that were synthesized by annealing silicon substrates coated with Au thin film under Ar–H₂ atmosphere at 1100 °C via the vapour–liquid–solid process. The morphologies and structures of the SiO_x–Au nanoflowers were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and helium ion microscopy. The results revealed that the silicon oxide–Au nanoflowers were amorphous with an Au nanoparticle core at the centre. As compared to simple SiO_x nanowires, the SiO_x–Au nanoflowers show a 5-fold enhancement in intensity of room temperature photoluminescence, which can be attributed to the unique nanostructures, the strong coupling between the photoluminescence emission of the SiO_x nanoflowers and the local surface plasmon resonance of the Au nanoparticles.