Chemical Engineering of Cu-Sn Disordered Network Metamaterials

Researchers from the Laboratory of Nanometallurgy developed a scalable design route and low-footprint strategy for the production of large-area, frequency-selective Cu-Sn disordered network metamaterials with quasi-perfect absorption. The Research is now published and featured on the supplementary cover of Nano Letters.


Research is now published and featured on the supplementary cover of Nano Letters.
The Research is now published and featured on the supplementary cover of Nano Letters.

The design and fabrication of large-area metamaterials is an ongoing challenge. Increasingly disordered materials are being explored as they offer new routes in fabrication and access to optical phenomena that rely on their intrinsic disorder. Many disordered materials do not rely on precise nanofabrication methods but can be realized through self-assembly of structural units, dewetting, or chemical dealloying.

In our work, we show how simple changes in the initial chemistry before dealloying can be used to engineer perfect absorption over a broad frequency range.

Through electron energy loss spectroscopy we could resolve plasmonic gap modes, confirming the formation of local hot spots of the electric field inside the disordered networks. This is especially exciting in regard to applications, where our open-porous networks can potentially be used as platforms for energy materials. This is for example by driving photovoltaic cells or photochemical processes, by taking advantage of “hot” carriers, i. e. electron-hole (e-h) pairs, resulting from the nonradiative decay of these plasmons. Intriguingly, the generation of hot carriers depends on both the chemistry and the local geometry, which can both be engineered with the design route outlined in this work.

The Research is now (January 26, 2022) published and featured on the supplementary cover of Nano Letterscall_made.

Chemical Engineering of Cu-Sn Disordered Network Metamaterials, Jelena Wohlwend, Alla S. Sologubenko, Max Döbeli, Henning Galinski, and Ralph Spolenak, Nano Letters 2022 22 (2), 853-859. DOI:10.1021/acs.nanolett.1c03545call_made

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