%0 Journal Article
%A Marcone, Jules
%A Juergensen, Sabrina
%A Barrios-Capuchino, Juan
%A Li, Xiaoyian
%A Goldmann, Claire
%A Köppen, Andrea
%A Pfeiffer, Winnie
%A Lehmkühler, Felix
%A Parak, Wolfgang
%A Kociak, Mathieu
%A Impéror-Clerc, Marianne
%A Reich, Stephanie
%A Hamon, Cyrille
%A Schulz, Florian
%T Plasmonic Polymorphs by Combining Shape Anisotropy and Soft Interactions in Bipyramid Thin Films
%J Small
%V 21
%N 31
%@ 1613-6810
%C Weinheim
%I Wiley-VCH
%M PUBDB-2025-01824
%P 2500389
%D 2025
%X Thin-film plasmonic supercrystals of pentagonal gold nanobipyramids (AuBP) exhibit a diverse range of packing structures that influence the near-field distribution of the enhanced electric field and the far-field response. By varying the molecular weight of the coating ligands, the softness of the anisotropic building blocks is changed. A thorough structural characterization reveals that this affects the resulting superstructures from self-assembly more intricately than with isotropic building blocks. Softer coatings lead to smaller aligned domains in monolayers, while bilayers exhibit more crystalline domains with dominant interlayer twist angles near 0° and 90°. The far-field distribution and near-field response are measured using micro-absorbance and electron energy loss spectroscopy (EELS). Correlating these data with high-resolution transmission electron microscopy (HR-TEM) structural analysis enabled the identification of the longitudinal and transverse individual and collective plasmonic modes. Notably, for large crystalline bilayer domains, a strong polarization-dependent optical response is observed. These features underline the potential of these superstructures for applications in surface-enhanced spectroscopies, plasmonic photocatalysis, and advanced optical manipulation in switchable optical metamaterials. 
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:40445581
%R 10.1002/smll.202500389
%U https://bib-pubdb1.desy.de/record/629647