Homogeneous Plasmonic Au Nanoparticles Fabrication Using in Situ Substrate Heating by Sputtering

increased usage of gold nanoparticles (au nps) in the high-tech world made these one of the pivotal components for large number of applications. in the present work, we present the fabrication of au nps and their characterisation for shape, size distribution and surface plasmon (sp) studies. au nps were synthesised on si substrate in a self-assembled manner with different densities. in situ substrate heating was done to fabricate au nps with minimum size variation and direct deposition of these on the si substrate. the prepared samples were then characterised by field emission scanning electron microscopy (fesem), atomic force microscopy (afm), high-resolution transmission electron microscope (hrtem), photoluminescence (pl) and uv-vis diffuse reflectance spectroscopy (uv-drs). the average size of the nanoparticles from fesem was found to be 3, 5 and 9 nm for substrate temperatures of 400, 500 and 600 °c, respectively. due to the high density of deposited au nps on the substrate, a strong and broad surface plasmon band was observed. uv spectra showed a shift in the absorption maxima towards the red region with increase in the temperature of substrate.