Self-assembled Au nanoparticles on heated Corning glass by dc magnetron sputtering: size-dependent surface plasmon resonance tuning

Abstract

We report on the growth of Au nanoparticles on Corning glass by direct current magnetron sputtering and on the optical absorption of the films. The substrate temperature was kept to relatively high temperatures of 100 o C or 450 o C. This lead to the growth of Au nanoparticles instead of smooth Au films as the surface energy of Au is much larger than the one of glass.The size of the particles depended on the substrate temperature and deposition time and was shown to follow a logarithmic normal distribution function. Both, the surface plasmon resonance position and bandwidth, were found to depend upon the average particle size. The surface plasmon resonance position showed a 75 nm continuous blue shift from 14 nm down to 2.5 nm average particle size. Thus, we have shown how to tune the nanoparticle size and surface plasmon resonance of Au by varying the substrate temperature and deposition time.The experimental results are reproduced reasonably using a method which is based on the size-and wavelength-dependent complex dielectric function of Au within the framework of the Mie theory for the optical properties of metallic nanospheres.

Growth of Au Nanoparticles in NiO via Short Annealing of Precursor Material Thin Film and Optimization of Plasmonics

“…The FWHM, Figure (c), decreases with annealing time and has similar behavior for the three films. It takes very small values, as small as 75–80 nm, which compares well to previous works for high quality LSPRs . This may well be attributed to improvements in the homogeneity of the samples …”

“…For example, in the case of Au or Ag nanoparticles, the optical absorption spectra in the visible light are dominated by localized surface plasmon resonance(s) (LSPR), which are resonances of charge density oscillations confined to metallic nanoparticles. LSPR depend on the size, shape, and dielectric environment of the nanoparticle . Thin films of such nanoparticles with LSPR find advanced technological applications in applied surface science, such us in clean energy, enhanced efficiency solar cells, bio‐ and chemical sensing, photocatalysis, LSPR‐based spectroscopies such as photoluminescence, surface‐enhanced Raman spectroscopies, etc .…”

A general theoretical and experimental framework for nanoscale electromagnetism

“…While the negative sign of Re d Au-AlO x ⊥ -and the associated blueshift of Re(ω −ω (0) ) (Figs. 3fhj, top panel)-agrees with earlier observations in Au [12][13][14] and Ag [16][17][18][19] nanoparticles, the spectral shift is significantly larger. There are two reasons: first, the nonclassical perturbation strength Re ω (eV) κ Au-AlO x ⊥ is much larger than in e.g.…”

Robustness of the far-field response of nonlocal plasmonic ensembles

“…State-of-the-art experiments range from single-particle spectroscopy with the aid of tightly focused electron beams15161718, to optical far-field measurements sampling the response of NP ensembles1920212223. In the latter case, nonlocal effects1724 and the concomitant inhomogeneous broadening can prove important for the interpretation of ensemble measurements.…”

“…The observation of size-dependent resonance shifts not anticipated from classical electrodynamics has recently renewed interest in plasmons in the sub-10-nm regime 15 16 17 . State-of-the-art experiments range from single-particle spectroscopy with the aid of tightly focused electron beams 15 16 17 18 , to optical far-field measurements sampling the response of NP ensembles 19 20 21 22 23 . In the latter case, nonlocal effects 17 24 and the concomitant inhomogeneous broadening can prove important for the interpretation of ensemble measurements.…”