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Abstract Key challenges limiting the adoption of metallic plasmonic nanostructures for practical devices include structural stability and the ease of large‐scale fabrication. Overcoming these issues may require novel metamaterial fabrication with potentials for improved durability under extreme conditions. Here, a self‐assembled growth of a hybrid plasmonic metamaterial in thin‐film form is reported, with epitaxial Ag nanopillars embedded in TiN, a mechanically strong and chemically inert matrix. One of the key achievements lies in the successful control of the tilt angle of the Ag nanopillars (from 0° to 50°), which is attributed to the interplay between the growth kinetics and thermodynamics during deposition. Such an anisotropic nature offered by the tilted Ag nanopillars in TiN matrix is crucial for achieving broadband, asymmetric optical selectivity. Optical spectra coupled with numerical simulations demonstrate strong plasmonic resonance, as well as angular selectivity in a broad UV–vis to near‐infrared regime. The nanostructured metamaterials in this work, which consist of highly conductive metallic nanopillars in a durable nitride matrix, have the potential to serve as a novel hybrid material platform for highly tailorable nanoscale metamaterial designs, suitable for high temperature optical applications.
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Nanoscale Thickness Control of Nanoporous Films Derived from Directionally Photopolymerized Mesophases
Abstract The preparation of thin films of nanostructured functional materials is a critical step in a diverse array of applications ranging from photonics to separation science. New thin‐film fabrication methods are sought to harness the emerging potential of self‐assembled nanostructured materials as next‐generation membranes. Here, the authors show that nanometer‐scale control over the thickness of self‐assembled mesophases can be enacted by directional photopolymerization in the presence of highly photo‐attenuating molecular species. Metrology reveals average film growth rates below ten nanometers per second, indicating that high‐resolution fabrication is possible with this approach. The trends in experimental data are reproduced well in numerical simulations of mean‐field frontal photopolymerization modeled in a highly photo‐attenuating and photo‐bleaching medium. These simulation results connect the experimentally observed nanometer‐scale control of film growth to the strong photo‐attenuating nature of the mesophase, which originates from its high‐aromatic‐ring content. Water permeability measurements conducted on the fabricated thin films show the expected linear scaling of permeability with film thickness. Film permeabilities compare favorably with current state‐of‐the‐art nanofiltration and reverse osmosis membranes, suggesting that the current approach may be utilized to prepare new nanoporous membranes for such applications.
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- Award ID(s):
- 1703494
- PAR ID:
- 10453845
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials Interfaces
- Volume:
- 8
- Issue:
- 5
- ISSN:
- 2196-7350
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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