Optimizing Interparticle Gaps in Large-Scale Gold Nanoparticle Supercrystals for Flexible Light-Matter Coupling

摘要

Periodic arrangements of plasmonic nanoparticles, supercrystals, featurestrong light–matter interaction. The light–matter coupling strength dependson the particle diameter and on the interparticle gaps, which provides a leverfor controlling it. To facilitate material design, experimental data is analyzedwith focus on how the reproducibility and tunability of the gap sizes changewith the employed nanoparticles (particle size and molecular weight of thestabilizing organic ligands). A different behavior of the polystyrene-basedligands was found depending on their molecular weight with importantconsequences for the correlation of nanoparticle diameter and resulting gapsin the supercrystals. Commonly employed models to predict the resultinggaps for supercrystals of small nanoparticles (< 20 nm) are not as successfulfor larger ones, and an alternative volume-based approach is presented.The tested parameters cover the range of commonly available nanoparticles(diameters in the range of 10–80 nm). The presented data provides robustguidelines for the preparation of crystalline superstructures with gaps below5 nm for maximized light–matter coupling.