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An aluminum‐on‐zirconium bilayer is anodized in oxalic acid solution to transform the Al layer into porous anodic alumina (PAA); this is followed by the PAA‐assisted re‐anodizing of the Zr underlayer at voltages 40–280 V. The process results in an array of amorphous ZrO2 nanocolumns, 45–330 nm long, partly filling the PAA pores and anchored to a continuous bottom oxide layer under the pores, 20–130 nm thick, comprising a ZrO1.8 spongelike sublayer superimposed on a ZrO1.5 compact sublayer. The thicknesses of the nanostructured and bottom oxides increase linearly with re‐anodizing voltage, disclosing a low film formation ratio of 1.65 nm V−1, which is impossible with anodic ZrO2. The amorphous ZrO2 nanocolumns embedded in the highly resistive amorphous PAA matrix combined with the laminated bottom oxide reveal a nearly ideal dielectric performance in a wide frequency range (10−4–104 Hz) complemented by the low leakage currents and high breakdown voltages (up to 280 V). The film permittivity may be tuned, from 11 to 20, by combining the anodizing and pore‐widening techniques. The advantageous architecture, fabrication approach, and functional properties of the films allow the design of a prototype of an emerging hybrid polymer electrolytic microcapacitor for on‐chip integration.

The fabrication of superhydrophobic-oleophobic HfO 2 coatings presents a challenge. Here, we synthesize via the self-organized anodizing of aluminum-on-hafnium layers sputterdeposited onto SiO 2 and glass substrate arrays of highly aligned HfO 2 nanostructures of dissimilar shapes, sizes, spacings, and population densities termed as nanorods, nanopillars, nanohoodoos, and nanopillars-in-domains, which were then modified with various self-assembled monolayers. The treatment in fluoroalkyl-trimethoxysilane (FAS-17) appeared to be the most effective in making the hafnium-oxide nanoarrays superhydrophobic, with water contact angles of 153°(nanopillars), 155°( nanorods), 160°(nanohoodoos), and 174°(nanopillars-indomains), the latter revealing the smallest roll-off angle of <1°. The FAS-17-modified HfO 2 nanorods and pillars-in-domains demonstrated the best oleophobic properties with a contact angle for ethylene glycol of 140°and for rapeseed oil of 121°. In addition, the HfO 2 nanorod films were highly transparent and antireflective in the visible spectral range and substantially less transparent and increasingly reflective in the near infrared. An outstanding combination of robust superhydrophobic-oleophobic properties with the specific optical behavior of the HfO 2 nanoarrays makes them attractive for application as self-cleaning visibletransparent heat-repelling dielectric coatings for solar cell coverglass and concentrator photovoltaics.