Structural Colours with Transition Metal Dichalcogenide Nanostructures

TL;DR

This paper explores the use of transition metal-dichalcogenide nanostructures, specifically nanosphere arrays, as a versatile platform for creating a wide spectrum of structural colours through simple geometric tuning.

Contribution

It introduces TMD nanostructures as a new platform for structural colours and analyzes how material properties and geometry influence the colour output.

Findings

TMD nanosphere arrays can produce a broad range of colours by adjusting size and spacing.

Different materials and lattice configurations expand the achievable colour space.

Excitonic effects and nanoparticle modes can be exploited for further colour tuneability.

Abstract

We introduce transition metal-dichalcogenide (TMD) nanostructures as a promising platform for the realisation of structural colours. Processing of semianalytically calculated reflectance spectra of TMD nanosphere arrays shows a wide range of colours, which are obtained simply through tailoring the radius and separation of spheres in the array, with the size-dependent Mie modes of the nanoparticles being the primary contributor to the spectra. Additionally, it is demonstrated that further coverage of the colour space can be obtained by employing different materials or different lattice unit cells. Theoretical examination of the impact of the excitonic attributes of TMDs on the resulting structural colours indicates that self-hybridisation between nanoparticle modes and excitonic transitions may be employed for further tuneability. Moreover, the impact of TMD anisotropy on the structural colours is shown to be negligible for small structures at typical viewing angles, while the viewing angle itself may impact the colour. This work sets out to be a general investigation of TMD nanoarchitectures, with a focus on nanosphere arrays, for structural colours, by examining both inherent material features through the lens of colourimetry, and the ability of such structures to sustain a broad range of hues.