Geometric structure and piezoelectric polarization of MoS2 nanoribbons under uniaxial strain

Abstract

Using density functional theory with the generalized gradient approximation and effective screening medium method, we investigated the geometric and piezoelectric properties of MoS2 nanoribbons under uniaxial strain in terms of their edge shapes. The strain ranged from 6% compressive to 6% tensile. Ribbons with zigzag and armchair edges are stiffer than those with chiral edges under compressive strain. Substantial edge reconstruction occurs at the chiral edges where S atomic sites are dominant under 6% compressive strain. Relative piezoelectric polarity between edges decreases and increases under compressive and tensile strains, respectively, when a ribbon possesses the zigzag edges, indicating possible application to piezoelectric devices. Polarity across a ribbon with armchair and chiral edges is insensitive to uniaxial strain except when there is edge reconstruction under a large compressive strain. The electronic structure of a ribbon slightly depends on uniaxial strain.