The field of molecular information handling and processing from a Boolean starting point has grown strongly during the past five years to make important contributions to the areas of intracellular...

Optical properties of nanoparticle assemblies reflect distinctive characteristics of their building blocks and spatial organization, giving rise to emergent phenomena. Integrated experimental and computational studies have established design principles connecting the structure to properties for assembled clusters and superlattices. However, conventional electromagnetic simulations are too computationally expensive to treat more complex assemblies. Here we establish a fast, materials agnostic method to simulate the optical response of large nanoparticle assemblies incorporating both structural and compositional complexity. This many-bodied, mutual polarization method resolves limitations of established approaches, achieving rapid, accurate convergence for configurations including thousands of nanoparticles, with some overlapping. We demonstrate these capabilities by reproducing experimental trends and uncovering far- and near-field mechanisms governing the optical response of plasmonic semiconductor nanocrystal assemblies including structurally complex gel networks and compositionally complex mixed binary superlattices. This broadly applicable framework will facilitate the design of complex, hierarchically structured, and dynamic assemblies for desired optical characteristics.

Gelation offers a powerful strategy to assemble plasmonic nanocrystal networks incorporating both the distinctive optical properties of constituent building blocks and customizable collective properties. Beyond what a single-component assembly can offer, the characteristics of nanocrystal networks can be tuned in a broader range when two or more components are intimately combined. Here, we demonstrate mixed nanocrystal gel networks using thermoresponsive metal–terpyridine links that enable rapid gel assembly and disassembly with thermal cycling. Plasmonic indium oxide nanocrystals with different sizes, doping concentrations, and shapes are reliably intermixed in linked gel assemblies, exhibiting collective infrared absorption that reflects the contributions of each component while also deviating systematically from a linear combination of the spectra for single-component gels. We extend a many-bodied, mutual polarization method to simulate the optical response of mixed nanocrystal gels, reproducing the experimental trends with no free parameters and revealing that spectral deviations originate from cross-coupling between nanocrystals with distinct plasmonic properties. Our thermoreversible linking strategy directs the assembly of mixed nanocrystal gels with continuously tunable far- and near-field optical properties that are distinct from those of the building blocks or mixed close-packed structures.

Optical properties of nanoparticle assemblies reflect the distinctive characteristics of their building blocks and their spatial organization, giving rise to emergent phenomena. Design of functional assemblies like clusters and superlattices has progressed through integrated experimental and computational studies establishing principles connecting structure to properties. However, conventional electromagnetic simulation methods are computationally expensive and inadequate for treating more complex assemblies, such as gels and mixed superlattices, hindering understanding and design. Here we establish a fast, materials agnostic method to simulate the optical response of large nanoparticle assemblies incorporating both structural and compositional complexity. This many-bodied, mutual polarization method resolves limitations of established approaches, achieving rapid convergence to accurate predictions even for configurations including thousands of nanoparticles, some touching or overlapping. The strategy naturally accommodates up to triply periodic boundary conditions. We demonstrate these capabilities by reproducing experimental trends and uncovering mechanisms governing the optical responses in assemblies of plasmonic semiconductor nanocrystals. Structurally complex gel networks and compositionally complex mixed binary superlattices with heterogeneity across length scales highlight the elucidation of both far- and near-field effects. This broadly applicable framework will facilitate design of more complex, hierarchically structured, and even dynamic assemblies for desired optical characteristics.

Optical properties of nanoparticle assemblies reflect the distinctive characteristics of their building blocks and their spatial organization, giving rise to emergent phenomena. Integrated experimental and computational studies have established design principles connecting structure to properties for assembled clusters and superlattices. However, conventional electromagnetic simulations are too computationally expensive to treat more complex assemblies. Here we establish a fast, materials agnostic method to simulate the optical response of large nanoparticle assemblies incorporating both structural and compositional complexity. This many-bodied, mutual polarization method resolves limitations of established approaches, achieving rapid, accurate convergence for configurations including thousands of nanoparticles, some overlapping. We demonstrate these capabilities by reproducing experimental trends and uncovering far- and near-field mechanisms governing the optical response of plasmonic semiconductor nanocrystal assemblies, including structurally complex gel networks and compositionally complex mixed binary superlattices. This broadly applicable framework will facilitate design of complex, hierarchically structured, and dynamic assemblies for desired optical characteristics.