Plasmonic Biomimetic Nanocomposite with Spontaneous Subwavelength Structuring as Broadband Absorbers

Abstract

Broadband plasmonic absorbers are essential components for photovoltaic, photothermal, and light-emitting devices. They are often made by lithographic processes that impart out-of-plane surface features with subwavelength dimensions to metallic films. However, lithographic subwavelength patterning of inexpensive plasmonic ceramics, such as TiN, is challenging because of high-temperature processing and the chemical robustness of these materials. In this work, we show that layer-by-layer assembly (LbL) of TiN plasmonic nanoparticles with polyelectrolytes results in spontaneous formation of out-of-plane topography with subwavelength dimensions. The columnar morphology of these corrugated coatings and their plasmonic functionality results in broadband absorption capabilities exemplified by 90% of the light from the ultraviolet to infrared parts of the spectrum being absorbed. The method is applicable to large, flexible, and conformal surfaces with complex geometry. It is also fast, scalable, and environmentally friendly. LBL processing of TiN nanoparticles demonstrates the possibility of replacement of lithographic patterning with stochastic self-assembly processes in manufacturing of photonic metasurfaces.

Design of Transparent Metasurfaces Based on Asymmetric Nanostructures for Directional and Selective Absorption

“…However, because of its good solar absorption performance, for practical application in the windows of buildings, these previously reported transparent solar absorbers are energy-saving in winter but energy-wasting in summer. In addition, the large-scale and further deployment of these reported transparent solar absorbers based on metasurfaces are also limited by the cost of noble metals, such as gold and silver [ 5 , 6 , 8 , 9 , 10 , 12 , 28 , 35 , 36 , 37 ]. Thus, it is a highly challenging and meaningful task to design and realize a metasurface using inexpensive materials, which can simultaneously achieve visible transparency, selective near-infrared absorption for front illumination, and selective near-infrared reflection for back illumination.…”

Harnessing Solar‐Driven Photothermal Effect toward the Water–Energy Nexus

“…[45] First, when the energy of incident light is higher than or equal to the bandgap of semiconductor, the electron-hole pairs will be motivated and generated within semiconductor. [47] In addition, a series of new narrow-bandgap semiconductors have been developed as the promising alternative to realize full-spectrum solar-to-heat, including CuS, [48,49] Ti 2 O 3 , [45] TiN, [50] TiAlN, [51] CuFeSe 2 , [52] and Te. However, most wide-bandgap semiconductors exhibit relatively narrow absorption wavelength.…”

“…Thanks to this treatment, its absorption wavelength is greatly broadened and is able to cover the whole solar spectrum, not only in UV regions but also in the visible and near‐infrared spectral regions . In addition, a series of new narrow‐bandgap semiconductors have been developed as the promising alternative to realize full‐spectrum solar‐to‐heat, including CuS, Ti 2 O 3 , TiN, TiAlN, CuFeSe 2 , and Te . It should be noted that their absorption efficiency can only reach 90% or lower in spite of covering full‐spectrum solar.…”

Plasmonics and its Applications

“…Moreover, theoretical, computational, and numerical simulation tools have been developed in this last decade, allowing for a better understanding of the optical properties of plasmonic systems [1]. Thus, all these optical properties of plasmonic systems can enable a great number of applications, such as biosensors [15,16,17,18,19,20], optical devices [21,22,23,24], and photovoltaic devices [25,26,27,28].…”