Ab initio study of anisotropic mechanical and electronic properties of strained carbon-nitride nanosheet with interlayer bonding

TL;DR

This study uses first-principles simulations to explore the anisotropic mechanical and electronic properties of a stable, covalently bonded carbon nitride nanosheet, revealing its exceptional stiffness and unique deformation responses.

Contribution

It provides the first detailed ab initio analysis of the elastic, vibrational, and electronic properties of a puckered CN nanosheet with interlayer bonding, highlighting its stability and anisotropic behavior.

Findings

CN nanosheet is structurally stable due to strong interlayer covalent bonds.

It exhibits an extremely high in-plane stiffness close to graphene.

The nanosheet shows a negative Poisson's ratio out-of-plane under biaxial strain.

Abstract

Due to the noticeable structural similarity and being neighborhood in periodic table of group-IV and -V elemental monolayers, whether the combination of group-IV and -V elements could have stable nanosheet structures with optimistic properties has attracted great research interest. In this work, we performed first-principles simulations to investigate the elastic, vibrational and electronic properties of the carbon nitride (CN) nanosheet in the puckered honeycomb structure with covalent interlayer bonding. It has been demonstrated that the structural stability of CN nanosheet is essentially maintained by the strong interlayer \so\ bonding between adjacent carbon atoms in the opposite atomic layers. A negative Poisson's ratio in the out-of-plane direction under biaxial deformation, and the extreme in-plane stiffness of CN nanosheet, only slightly inferior to the monolayer graphene, are revealed. Moreover, the highly anisotropic mechanical and electronic response of CN nanosheet to tensile strain have been explored.