Thermodynamics of carbon point defects in hexagonal boron nitride

TL;DR

This study uses first-principles calculations to analyze the thermodynamics of various carbon defects in hexagonal boron nitride, highlighting the most prevalent defect types and their potential role in single-photon emission.

Contribution

It provides a comprehensive thermodynamic analysis of multiple carbon defect configurations in hBN using first-principles methods, identifying the most common defect species under typical growth conditions.

Findings

Monomers, dimers, trimers, and C_N O_N pairs are most prevalent defects.

Larger carbon clusters and complexes are less common.

Results suggest specific defects may influence single-photon emission in hBN.

Abstract

We present a first-principles computational study of the thermodynamics of carbon defects in hexagonal boron nitride (hBN). The defects considered are carbon monomers, dimers, trimers, and larger carbon clusters, as well as complexes of carbon with vacancies, antisites, and substitutional oxygen. Our calculations show that monomers ($\text{C}_{\text{B}}$, $\text{C}_{\text{B}}$), dimers, trimers, and $\text{C}_{\text{N}}\text{O}_{\text{N}}$ pairs are the most prevalent species under most growth conditions. Compared to these defects, larger carbon clusters, as well as complexes of carbon with vacancies and antisites, occur at much smaller concentrations. Our results are discussed in view of the relevance of carbon defects in single-photon emission in hBN.