Stability of hydrogenated group-IV nanostructures: magic structures of diamond nanocrystals and Silicon quantum dots

TL;DR

This paper introduces an effective model validated by first-principles calculations to analyze the stability of hydrogenated group-IV nanostructures, revealing stable 'magic' structures like diamond nanocrystals and silicon quantum dots.

Contribution

The study develops an analytical Hamiltonian model that explains stability patterns and enables efficient identification of stable nanostructures, advancing understanding of hydrogenated group-IV nanomaterials.

Findings

Hamiltonian expressed as linear combination of atom numbers

Explains experimentally observed stable nanostructures

Provides a reliable method for searching magic structures

Abstract

We have developed an effective model to investigate the energetic stability of hydrogenated group-IV nanostructures, followed by validations from first-principles calculations. It is found that the Hamiltonian of X$_{m}$H$_{n}$ (X=C, Si, Ge and Sn) can be expressed analytically by a linear combination of the atom numbers ($m$, $n$), indicating a dominating contribution of X$-$X and X$-$H local interactions. As a result, we explain the stable nanostructures observed experimentally, and provide a reliable and efficient technique of searching the magic structures of diamond nanocrystals(Dia-NCs) and Silicon quantum dots(SiQDs).