Orientation-dependent stability and quantum-confinement effects of silicon carbide nanowires

TL;DR

This study uses first-principles calculations to analyze the stability and electronic properties of hydrogenated silicon carbide nanowires with different orientations and structures, revealing orientation-dependent stability and quantum confinement effects.

Contribution

It provides new insights into the stability and electronic behavior of SiC nanowires based on their orientation and structure, supported by first-principles calculations.

Findings

[111]-oriented 3C-SiCNWs are most stable

Band gaps decrease with increasing wire size due to quantum confinement

Direct band gaps are maintained in certain orientations up to 2.8 nm diameter

Abstract

The energetic stability and electronic properties of hydrogenated silicon carbide nanowires (SiCNWs) with zinc blende (3C) and wurtzite (2H) structures are investigated using first-principles calculations within density functional theory and generalized gradient approximation. The [111]-orientated 3C-SiCNWs are energetically more stable than other kinds of NWs with similar size. All the NWs have direct band gaps except the 3C-SiCNWs orientating along [112] direction. The band gaps of these NWs decrease with the increase of wire size, due to the quantum-confinement effects. The direct-band-gap features can be kept for the 3C-SiCNWs orientating along [111] direction with diameters up to 2.8 nm. The superior stability and electronic structures of the [111]-orientated 3C-SiCNWs are in good agreement with the experimental results.