Study of volume and surface plasmons in small silicon-hydrogen nanoclusters by GW method

TL;DR

This study uses the GW computational method to analyze surface and volume plasmons in small silicon and silicon-hydrogen nanoclusters, revealing how surface passivation influences plasmon properties and their distinguishability.

Contribution

It applies the GW method to nanoclusters, demonstrating the impact of surface passivation on plasmon frequencies and damping, with results aligning with experimental data.

Findings

Surface passivation shifts plasmon frequencies.

Passivation reduces plasmon damping.

Surface effects are crucial in small clusters.

Abstract

Numerical calculations of surface and volume plasma excitations in silicon and silicon-hydrogen nanoclusters in the range Si$_{10}$-Si$_{60}$ and Si$_3$H$_8$-Si$_{39}$H$_{40}$ are performed. Some nanocluster structures were obtained using the evolutionary algorithm, others were taken from the database. The GW method was used to calculate the response function and self-energy of the structures under study. The applied method shows the results consistent with the experiment (except plasmaron artifacts) and sufficient sensitivity allowing to investigate the effect of the cluster structure and size on the specific properties of plasma excitations. In the studied silicon and silicon-hydrogen nanoclusters the surface is one of the key factors affecting the properties of the plasmons. Passivation of silicon dangling bonds on cluster surface changes frequency of plasmons and significantly decreases their damping. It makes the surface and volume plasmons to be clearly distinguishable even in small clusters.