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This study shows the fabrication by a dry approach at mild temperature (

In this work we have developed an infiltration methodology to incorporate metal nanoparticles (NPs) of controlled size and shape into the open voids available in oblique angle deposited thin films. These NPs exhibited well-defined surface plasmon resonances (SPRs). The nanometric confined space provided by their porous microstructure has been used as a template for the growth of anisotropic NPs with interesting SPR properties. The fabrication methodology has been applied for the preparation of films with embedded Ag and Au NPs with two associated plasmon resonance features that developed a dichroic behaviour when examined with linearly polarized light. A confined alloying process was induced by near IR nanosecond laser irradiation yielding bimetallic NPs with SPR features covering a large zone of the electromagnetic spectrum. The possibilities of the method for the tailored fabrication of a wide range colour palette based on SPR features are highlighted.

Oblique angle deposition (OAD) is a powerful technique for the fabrication of porous nanostructured oxide thin films. OAD films typically present a columnar tilted nanostructure due to geometrical shadowing effects during the thin film growth. In this work, we study the fabrication of transparent and conducting indium tin oxide films (ITO) by OAD assisted by a microwave ECR plasma. The objective of assisting the deposition with a plasma discharge is to modify the growth mechanism of the OAD process introducing additional parameters to control the columnar microstructure, composition, porosity of the films. The results indicate the OAD ITO deposition assisted by the plasma discharge is a very effective process to develop in-plane structural anisotropy in the ITO nanocolumnar films what determines their electrical properties.

Porous Bragg microcavities formed by stacking a series of porous nanocolumnar layers with alternate low (SiO2) and high (TiO 2) refractive index materials have been prepared by physical vapor deposition at glancing angles (GLAD). By strictly controlling the porosity and refractive index of the individual films, as well as the relative orientation of the nanocolumns from one layer to the next, very porous and nondispersive high optical quality microcavities have been manufactured. These photonic structures have been implemented into responsive devices to characterize liquids, mixtures of liquids, or solutions flowing through them. The large displacements observed in the optical spectral features (Bragg reflector gap and resonant peak) of the photonic structures have been quantitatively correlated by optical modeling with the refractive index of the circulating liquids. Experiments carried out with different glucose and NaCl solutions and mixtures of water plus glycerol illustrate the potentialities of these materials to serve as optofluidic devices to determine the concentration of solutions or the proportion of two phases in a liquid mixture. © 2013 American Chemical Society.

ITO thin films have been prepared by electron beam evaporation at oblique angles (OA), directly and while assisting their growth with a downstream plasma. The films microstructure, characterized by scanning electron microscopy, atomic force microscopy, and glancing incidence small-angle X-ray scattering, consisted of tilted and separated nanostructures. In the plasma assisted films, the tilting angle decreased and the nanocolumns became associated in the form of bundles along the direction perpendicular to the flux of evaporated material. The annealed films presented different in-depth and sheet resistivity as confirmed by scanning conductivity measurements taken for the individual nanocolumns. In addition, for the plasma-assisted thin films, two different sheet resistance values were determined by measuring along the nanocolumn bundles or the perpendicular to it. This in-plane anisotropy induces the electrochemical deposition of elongated gold nanostructures. The obtained Au-ITO composite thin films were characterized by anisotropic plasmon resonance absorption and a dichroic behavior when examined with linearly polarized light.

A flexible distributed Bragg reflector is made by the infiltration of a nanocolumnar array with polydimethyl siloxane oligomers. The high optical reflectance displayed by the final material is a direct consequence of the high refractive index contrast of the columnar layers whereas the structural stability is due to the polymer properties. Unión Europea FP7 / 2007-2013 Ministerio de Economía y Competitividad MAT2011-23593 Ministerio de Economía y Competitividad MAT2013-42900-P Junta de Andalucía FQM6900 Junta de Andalucía TEP8067 Convenio de subvención ERC 307081 (POLIGHT)

In this article we present the preactivation of TiO2 and ITO by UV irradiation under ambient conditions as a tool to enhance the incorporation of organic molecules on these oxides by evaporation at low pressures. The deposition of π-stacked molecules on TiO2 and ITO at controlled substrate temperature and in the presence of Ar is thoroughly followed by SEM, UV–vis, XRD, RBS, and photoluminescence spectroscopy, and the effect is exploited for the patterning formation of small-molecule organic nanowires (ONWs). X-ray photoelectron spectroscopy (XPS) in situ experiments and molecular dynamics simulations add critical information to fully elucidate the mechanism behind the increase in the number of adsorption centers for the organic molecules. Finally, the formation of hybrid organic/inorganic semiconductors is also explored as a result of the controlled vacuum sublimation of organic molecules on the open thin film microstructure of mesoporous TiO2., We thank the Junta de Andalucia (TEP8067, FQM-6900, and P12-FQM-2265) and the Spanish Ministry of Economy and Competitiveness (projects CONSOLIDER-CSD 2008-00023, MAT2011-28345-C02-02, MAT2013-40852-R, MAT2013- 42900-P, and RECUPERA 2020) for financial support.

Glancing angle deposited (GLAD) oxide thin films are quite interesting materials due to the wide variety of nanostructures that can be obtained with this method. Most important properties of the oxide GLAD thin films rely in the possibility to tailor their nanostructure in the form of tilted columns and other more complex forms. This nanostructure is caused by geometrical shadowing effects during the thin film growth. Porous GLAD films have been used as hosts or templates to fabricate new nanocomposite materials and other complex optical nanostructures like photonic crystals, dye sensitized solar cells, optical sensors and microfluidic devices. [1-3] In this work we study the fabrication of transparent and conducting Indium tin oxide films (ITO) by a novel synthetic approach consisting in GLAD deposition assisted by a microwave ECR plasma. The ECR microwave discharges are fully compatible with the range of pressures required for the electron evaporation process utilized for the deposition of the ITO thin films. The objective of the plasma is to modify the growth mechanism of the GLAD process in order to control the columnar microstructure, porosity and the properties of the films [4]. As it will be shown, the GLAD ITO deposition assisted by the plasma discharge is a very effective process to develop in-plane anisotropy in the ITO films what determines the films properties. [1] M. J. Brett et al. Science, 319 (2008) 1192. [2] A. Barranco et al. Progress in Materials Science 76, (2016) 59-153. [2] González-García et al, Nanotechnology 23 205701, 2012. [3] Gonzalez-García et al. Energy. Environ. Sci. 4, 2011, 3426. [4] J. Parra-Barranco et al. ACS Appl. Mater. Interf. 7, 2015, 10993.

We present a straightforward procedure of self-surface patterning with potential applications as large area gratings, invisible labeling, optomechanical transducers, or smart windows. The methodology is based in the formation of parallel micrometric crack patterns when polydimethylsiloxane foils coated with tilted nanocolumnar SiO2 thin films are manually bent. The SiO2 thin films are grown by glancing angle deposition at room temperature. The results indicate that crack spacing is controlled by the film nanostructure independently of the film thickness and bending curvature. They also show that the in-plane microstructural anisotropy of the SiO2 films due to column association perpendicular to the growth direction determines the anisotropic formation of parallel cracks along two main axes. These self-organized patterned foils are completely transparent and work as customized reversible diffraction gratings under mechanical activation. © 2014 American Chemical Society.

A simple method is presented to tune the gold surface plasmon resonance (SPR) modes by growing anisotropic nanoparticles into transparent SiO 2 thin films prepared by glancing angle deposition. In this type of composite film, the anisotropy of the gold nanoparticles, proved by gracing incidence small angle X-ray scattering, is determined by the tilted nanocolumnar structure of the SiO2 host and yields a strong film dichroism evidenced by a change from an intense colored to a nearly transparent aspect depending on light polarization and/or sample orientation. The formation in these films of lithographic non-dichroic SPR patterns by nanosecond laser writing demonstrates the potentialities of this procedure to develop novel optical encryption or anti-counterfeiting structures either at micrometer- or macroscales. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., We thank the Junta de Andalucía (Projects P09-CTS-5189, TEP5283, and FQM-6900) and the Ministry of Economy and Competitiveness (Projects CONSOLIDERCSD 2008-00023, MAT2010-21228, MAT2011-23455, and MAT2010-18447) for financial support. European Community [Contract RII3-CT-2004–506008 (IASFS)].