Plasmon Resonance of Isolated Gold Hollow Nanoparticles and Nanoparticle Pairs: Insights from Electronic Structure Calculations

Abstract

Because the feature sizes of noble metal nanoparticles (NPs) are smaller than a few of nanometers, simulations including quantum effects and atomistic details are inevitable. In this work, we report a detailed electronic structure study on the plasmon resonance of isolated gold hollow nanoparticles (NPs) and NP pairs. The long-range-corrected (LRC) density functional theory (DFT) has been employed. We find that the plasmon resonance of small-size gold NPs is very sensitive to NP sizes and interparticle distances. When the NP’s size changes from Au32 to Au17–, the high-energy absorption maximum blue shifts 50 nm and when the interparticle distance of Au17– NP pairs changes from 1.15 to 0.83 nm, the corresponding blue shift is ∼40 nm. The spectral line width becomes narrower as the NP size increases and the interparticle distance reduces. The insight of how the plasmon-resonance peaks of a NP pair are formed and how they are sensitive to the interparticle separation is revealed by the plots of transition de...