Electronic structures and edge effects of Ga2S2 nanoribbons

TL;DR

This study uses ab initio density functional theory to explore how edge structures influence the electronic properties and stability of Ga2S2 nanoribbons, revealing edge-dependent metallic or semiconducting behavior and stability differences.

Contribution

It provides detailed insights into the edge effects on electronic properties and stability of Ga2S2 nanoribbons, highlighting the impact of edge structure and passivation.

Findings

Zigzag nanoribbons are metallic with spin-polarized edge states.

Armchair nanoribbons are semiconducting with an oscillating band gap.

Armchair nanoribbons are more stable than zigzag ones.

Abstract

Ab initio density functional theory calculations are carried out to predict the electronic properties and relative stability of gallium sulfide nanoribbons (Ga2S2-NRs) with either zigzag- or armchair-terminated edges. It is found that the electronic properties of the nanoribbons are very sensitive to the edge structure. The zigzag nanoribbons (Ga2S2-ZNRs) are metallic with spin-polarized edge states regardless of the H-passivation,whereas the bare armchair ones (Ga2S2-ANRs) are semiconducting with an indirect band gap. This band gap exhibits an oscillation behavior as the width increases and finally converges to a constant value. Similar behavior is also found in H-saturated Ga2S2-ANRs, although the band gap converges to a larger value. The relative stabilities of the bare ANRs and ZNRs are investigated by calculating their binding energies. It is found that for a similar width the ANRs are more stable than the ZNRs, and both are more stable than some Ga2S2 nanocluters with stable configurations.