Fabrication of black-gold coatings by glancing angle deposition with sputtering

The fabrication of black-gold coatings using sputtering is reported here. Glancing angle deposition with a rotating substrate is needed to obtain vertical nanostructures. Enhanced light absorption is obtained in the samples prepared in the ballistic regime with high tilt angles. Under these conditions the diameter distribution of the nanostructures is centered at about 60 nm and the standard deviation is large enough to obtain black-metal behavior in the visible rangeEspaña Mineco MAT2014-59772-C2-1 MAT2015-69035-RED

Thin film nanostructuring at oblique angles by substrate patterning

It is demonstrated that, besides classical nanocolumnar arrays, the oblique angle geometry induces the growth of singular structures in the nanoscale when using wisely designed patterned substrates. Well-ordered array of crosses, cylindrical nanorods or hole structures arranged in square or hexagonal regular geometries are reported as examples, among others. The fundamental framework connecting substrate topography and film growth at oblique angles is presented, allowing the use of substrate patterning as a feasible thin film nanostructuring technique. A systematic analysis of the growth of TiO2 thin films on 4 different lithographic patterned substrates in 4 different scale lengths is also presented. A first conclusion is the existence of a height-based selective growth in the initial stages of the deposition, by which the film preferentially develops on top of the tallest substrate features. This behavior is maintained until the film reaches a critical thickness, the so-called Oblivion Thickness, above which the film topography becomes gradually independent of the substrate features. A general formula relating the spatial features of the pattern, the coarsening exponent and the Oblivion Thickness has been deduced.MCIN/AEI/and FEDER project PID2019-110430GB-C21MCIN/AEI/ and FEDER project PID2020-112620GB-I00MCIN/AEI/ and FEDER project PID2020-114270RA-I00MCIN/AEI/ and FEDER project RTI2018-098117-B-C21Junta de Andalucía PAIDI-2020 project P18-RT-3480Junta de Andalucía PAIDI-2020 project P18-RT-6079University of Seville VI PPIT-U