The utility of sputtering in manufacturing thin films is widely acknowledged, particularly within industrial contexts. This technique boasts considerable versatility, enabling the manufacturing of nanocolumnar films (NCs) from various materials through substrate tilting during atom deposition. Regarding Au NCs, they have been used for several applications: as black metal coatings in the visible spectrum [1], as bioelectrodes [2] and as templates for the identification of molecules with SERS, Surface Enhanced Raman Scattering [3,4]. The present work seeks to examine the presence of plasmons in these Au NCs, with the aim of leveraging them as a heat source via photothermal methods or as biosensor probes. This thermal effect is being investigated as a precursor in catalytic processes and for localized tumour treatment [5]. Diverse morphologies of Au nanostructures have been produced on silicon substrates in this work: i) a thin film, for the sake of comparison; ii) a vertical nanocolumnar film, and iii) a film featuring tilted nanocolumns. Morphological characterization of the samples was performed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Their crystalline and electronic structures were assessed through X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) at the Au L3’ edge (11919 eV). The latter two techniques were carried out at BM25 and BM30 beamlines, respectively, at the European Synchrotron Radiation Facility (ESRF, France). Finally, the optical properties of these films have been examined using an ellipsometer and a reflectivity measurement system custom-assembled within the laboratory. The different nanostructuring of the films will impart varying optical properties to them, facilitating the identification of those most suitable for the mentioned applications.

Funding from PID2021-126524NB-I00, PID2021-127033OB-C21 and Ministerio de Universidades through a FPU grant (FPU/02272). We acknowledge the BM30 and BM25 beamline staff for their assistance

Resumen del trabajo presentado en IEEE Nano 2024 - 24th IEEE International Conference on Nanotechnology, celebrado en Gijón (España), del 8 al 11 de julio de 2024