Exploring Transition Metal Dichalcogenide Nanostructures for Electrically Tunable Structural Colors

We introduce transition metal-dichalcogenide (TMD) nanostructures as a promising platform for the realization of tunable structural colors. Processing of semianalytically calculated reflectance spectra of TMD nanosphere arrays shows a wide range of colors, 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 color 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 colors indicates considerable significance, which may be employed for further tuneability via electronic gating. Moreover, the impact of TMD anisotropy on the structural colors is shown to be negligible for small structures at typical viewing angles, while the viewing angle itself may impact the color. This work sets out to be a general investigation of TMD nanoarchitectures, with a focus on nanosphere arrays, for structural colors, by examining both inherent material features through the lens of colorimetry, and the ability of such structures to sustain a broad range of hues.