An Ultra-Thin Near-Perfect Absorber via Block Copolymer Engineered Metasurfaces

• Published in: Journal of colloid and interface science Vol. 609; pp. 375 - 383
• Main Authors: Cummins, Cian, Flamant, Quentin, Dwivedi, Ranjeet, Alvarez-Fernandez, Alberto, Demazy, Nils, Bentaleb, Ahmed, Pound-Lana, Gwenaelle, Zelsmann, Marc, Barois, Philippe, Hadziioannou, Georges, Baron, Alexandre, Fleury, Guillaume, Ponsinet, Virginie
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2022; Elsevier
• Subjects: Block copolymers; Chemical Sciences; Engineering Sciences; Flat optics; Material chemistry; Metasurfaces; Nanoresonators; Optics; Perfect absorbers; Photonic; Flat optics; Metasurfaces; Nanoresonators; Perfect absorbers; Block copolymers; nanoresonators; metasurfaces; flat optics; perfect absorbers
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2021.11.163

[Display omitted] Producing ultrathin light absorber layers is attractive towards the integration of lightweight planar components in electronic, photonic, and sensor devices. In this work, we report the experimental demonstration of a thin gold (Au) metallic metasurface with near-perfect visible absorption (∼95 %). Au nanoresonators possessing heights from 5 − 15 nm with sub-50 nm diameters were engineered by block copolymer (BCP) templating. The Au nanoresonators were fabricated on an alumina (Al2O3) spacer layer and a reflecting Au mirror, in a film-coupled nanoparticle design. The BCP nanopatterning strategy to produce desired heights of Au nanoresonators was tailored to achieve near-perfect absorption at ≈ 600 nm. The experimental insight described in this work is a step forward towards realizing large area flat optics applications derived from subwavelength-thin metasurfaces.