A Library of Late Transition Metal Alloy Dielectric Functions for Nanophotonic Applications. (1st June 2020) - Rahm, J. Magnus
Abstract: Accurate complex dielectric functions are critical to accelerate the development of rationally designed metal alloy systems for nanophotonic applications, and to thereby unlock the potential of alloying for tailoring nanostructure optical properties. To date, however, accurate alloy dielectric functions are widely lacking. Here, a time‐dependent density‐functional theory computational framework is employed to compute a comprehensive binary alloy dielectric function library for the late transition metals most commonly employed in plasmonics (Ag, Au, Cu, Pd, Pt). Excellent agreement is found between electrodynamic simulations based on these dielectric functions and selected alloy systems experimentally scrutinized in 10 at% composition intervals. Furthermore, it is demonstrated that the dielectric functions can vary in very non‐linear fashion with composition, which paves the way for non‐trivial optical response optimization by tailoring material composition. The presented dielectric function library is thus a key resource for the development of alloy nanomaterials for applications in nanophotonics, optical sensors, and photocatalysis. Abstract : A library of the dielectric functions of the ten binary alloys formed by combinations of gold, silver, copper, palladium, and platinum is presented. Accuracy is confirmed by comparison of calculated and measured optical extinction spectra. The results reveal non‐trivial trends that pave the way for optimization of a wide range of nanophotonic applications.