Creation and plasmon anisotropy spectroscopy of wedge-shaped gold nanoclusters conditioned by GaAs(001) surface

• Published in: Surface science 2024-04, Vol.742, p.122437, Article 122437
• Main Authors: Berkovits, V.L., Kosobukin, V.A., Ulin, V.P., Alekseev, P.A., Borodin, B.R., Soldatenkov, F.Yu, Nashchekin, A.V., Khakhulin, S.A., Komkov, O.S.
• Format: Article
• Language: English
• Subjects: Anisotropic plasmons; Au-GaAs interaction; Polarization spectroscopy; Wedge-shaped Au clusters
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2023.122437

•Wedge-shaped gold nanoclusters are created on gallium arsenide surface.•Elongated Au-wedge nanoclusters are equally oriented on GaAs crystal surface.•Gold cluster-wedges possess plasmons in infrared and visible ranges.•Plasmon anisotropy of gold nanowedges is revealed by optical polarization spectroscopies. Wedge-shaped nanoclusters of gold (Au2Ga) are fabricated by high-temperature annealing of a gold nanofilm deposited onto (001) surface of p-doped GaAs crystal with a very thin overlayer of natural oxide. The data of diagnostics confirm the presence in prepared Au/p-GaAs(001) structures of the wedge-shaped Au-intermetallic nanoclusters elongated in [110] direction at GaAs surface. A crystallographic model of the wedge-shaped Au (Au2Ga) nanoclusters conditioned by GaAs(001) surface is discussed in relation with their physicochemical nature. Anisotropic plasmons localized on equally oriented Au-based nanoclusters are detected optically with the reflectance anisotropy spectroscopy and investigated thoroughly with the spectroscopy of polarized light reflection. It is proved experimentally and theoretically that the inhomogeneously broadened infrared spectral peak at the energy about 1.1 eV is associated with plasmons polarized along the wedge-shaped clusters in [110] crystal direction. Another peak - at the energy approximately of 1.8 eV - is due to plasmons having orthogonal polarization in direction [11¯0]. [Display omitted]