Enhanced photoluminescence from SiOx–Au nanostructures†
Highly efficient photoluminescence (PL) emission is obtained from flower-like silicon oxide (SiOx)–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 SiOx–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 SiOx nanowires, the SiOx–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 SiOx nanoflowers and the local surface plasmon resonance of the Au nanoparticles.