Chemical and Physical Properties of Photonic Noble‐Metal Nanomaterials

• Published in: Advanced materials (Weinheim) Vol. 35; no. 34; pp. e2108104 - n/a
• Main Authors: Cai, Yi‐Yu, Choi, Yun Chang, Kagan, Cherie R.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.08.2023
• Subjects: assembly; Materials science; Metamaterials; metamolecules; Nanomaterials; Nanoparticles; Noble metal nanoparticles; Noble metals; Optical properties; Physical properties; plasmonic; Plasmonics; Polaritons; Superlattices; Superstructures; Thin films; assembly; Noble metal nanoparticles; metamaterials; plasmonic; metamolecules
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202108104

Colloidal noble metal nanoparticles (NPs) are composed of metal cores and organic or inorganic ligand shells. These NPs support size‐ and shape‐dependent plasmonic resonances. They can be assembled from dispersions into artificial metamolecules which have collective plasmonic resonances originating from coupled bright and dark optical electric and magnetic modes that form depending on the size and shape of the constituent NPs and their number, arrangement, and interparticle distance. NPs can also be assembled into extended 2D and 3D metamaterials that are glassy thin films or ordered thin films or crystals, also known as superlattices and supercrystals. The metamaterials have tunable optical properties that depend on the size, shape, and composition of the NPs, and on the number of NP layers and their interparticle distance. Interestingly, strong light‐matter interactions in superlattices form plasmon polaritons. Tunable interparticle distances allow designer materials with dielectric functions tailorable from that characteristic of an insulator to that of a metal, and serve as strong optical absorbers or scatterers, respectively. In combination with lithography techniques, these extended assemblies can be patterned to create subwavelength NP superstructures and form large‐area 2D and 3D metamaterials that manipulate the amplitude, phase, and polarization of transmitted or reflected light. Noble metal nanoparticles (NPs) serve as building blocks in the assembly of artificial metamolecules and large‐area metamaterials. These metastructures have exotic optical properties that depend on the NP number, arrangement, and interparticle spacing, and on the geometry of their patterned 2D and 3D superstructures. Their strong light‐matter interactions are harnessed to manipulate the amplitude, phase, and polarization of light.