Nitrogenated, Phosphorated and Arsenicated Monolayer Holey Graphenes

TL;DR

This study uses first-principles calculations to explore the properties of nitrogenated, phosphorated, and arsenicated holey graphene monolayers, revealing their stability, electronic, magnetic, and mechanical characteristics relevant for optoelectronic applications.

Contribution

It introduces and analyzes three new holey graphene monolayers (C₂N, C₂P, C₂As), demonstrating their stability and potential for optoelectronic use, expanding on the experimentally synthesized C₂N.

Findings

All three monolayers are energetically feasible and stable.

They are direct band gap semiconductors with mechanical stability.

Defects and impurities can induce metallicity and magnetism.

Abstract

Motivated by a recent experiment that reported the synthesis of a new 2D material nitrogenated holey graphene (C$_2$N) [Mahmood \textit{et al., Nat. Comm.}, 2015, \textbf{6}, 6486], electronic, magnetic, and mechanical properties of nitrogenated (C$_2$N), phosphorated (C$_2$P) and arsenicated (C$_2$As) monolayer holey graphene structures are investigated using first-principles calculations. Our total energy calculations indicate that, similar to the C$_2$N monolayer, the formation of the other two holey structures are also energetically feasible. Calculated cohesive energies for each monolayer show a decreasing trend going from C$_2$N to C$_2$As structure. Remarkably, all the holey monolayers are direct band gap semiconductors. Regarding the mechanical properties (in-plane stiffness and Poisson ratio), we find that C$_2$N has the highest in-plane stiffness and the largest Poisson ratio among the three monolayers. In addition, our calculations reveal that for the C$_2$N, C$_2$P and C$_2$As monolayers, creation of N and P defects changes the semiconducting behavior to a metallic ground state while the inclusion of double H impurities in all holey structures results in magnetic ground states. As an alternative to the experimentally synthesized C$_2$N, C$_2$P and C$_2$As are mechanically stable and flexible semiconductors which are important for potential applications in optoelectronics.