Point Defects in Two-Dimensional {\gamma}-Phosphorus Carbide

TL;DR

This study uses density functional theory to analyze various point defects in the 2D gamma-phosphorus carbide, revealing their stability, electronic effects, and experimental detectability, which are crucial for understanding and engineering its properties.

Contribution

It provides a comprehensive DFT-based analysis of seven types of point defects in gamma-phosphorus carbide, highlighting their stability, electronic impact, and experimental identification methods.

Findings

Defects are stable in gamma-PC but less favorable than in graphene.

Point defects significantly modulate electronic properties by doping.

Most defects are distinguishable in scanning tunneling microscopy images.

Abstract

Defects are inevitably present in two-dimensional (2D) materials and usually govern their various properties. Here a comprehensive density functional theory-based investigation of 7 kinds of point defects in a recently produced {\gamma} allotrope of 2D phosphorus carbide ({\gamma}-PC) is conducted. The defects, such as antisites, single C or P, and double C and P and C and C vacancies, are found to be stable in {\gamma}-PC, while the Stone-Wales defect is not presented in {\gamma}-PC due to its transition metal dichalcogenides-like structure. The formation energies, stability, and surface density of the considered defect species as well as their influence on the electronic structure of {\gamma}-PC is systematically identified. The formation of point defects in {\gamma}-PC is found to be less energetically favourable then in graphene, phosphorene, and MoS2. Meanwhile, defects can significantly modulate the electronic structure of {\gamma}-PC by inducing hole/electron doping. The predicted scanning tunneling microscopy images suggest that most of the point defects are easy to distinguish from each other and that they can be easily recognized in experiments.