Eliminating edge electronic and phonon states of phosphorene nanoribbon by unique edge reconstruction

TL;DR

This study reveals a unique edge reconstruction in bilayer phosphorene nanoribbons that significantly reduces edge energy, alters electronic properties to resemble the intrinsic 2D layer, and enhances thermal conductivity, with implications for material stability and applications.

Contribution

The paper identifies a lowest-energy edge reconstruction in phosphorene nanoribbons that dominates naturally and modifies electronic and thermal properties.

Findings

Reconstruction reduces edge energy by 60%.

Electronic band structure becomes nearly edgeless.

Thermal conductivity increases by 1.4 to 2.3 times.

Abstract

Edge termination plays a vital role in determining the properties of 2D materials. By performing compelling ab initio simulations, a lowest-energy U-edge [ZZ(U)] reconstruction is revealed in the bilayer phosphorene. Such reconstruction reduces 60% edge energy compared with the pristine one and occurs almost without energy barrier, implying it should be the dominating edge in reality. The electronic band structure of phosphorene nanoribbon with such reconstruction resembles that of intrinsic 2D layer, exhibiting nearly edgeless band characteristics. Although ZZ(U) changes the topology of phosphorene nanoribbon (PNR), simulated TEM, STEM and STM images indicates it is very hard to be identified. One possible identify method is IR/Raman analyses because ZZ(U) edge alters vibrational modes dramatically. Beyond, it also increases the thermal conductivity of PNR 1.4 and 2.3 times than the pristine and Klein edges.