Electromechanical response of stacked h-BN layers: A computational study

Abstract

In the current investigation, molecular dynamics simulations were performed to determine the electromechanical response of multi-layer boron nitride sheets (MLBNSs) with the consideration of different numbers of stacked layers, strain rate (SR), temperature and chirality effects, and fracture behavior subjected to uniaxial tensile tests. We found the stress–strain curves and evaluated the elastic modulus, fracture strain, and maximum tensile strength in the armchair (AC) and zigzag (ZZ) directions of BNSs. We assessed the impact of two parameters (number of stacked layers and chirality effect) on the tensile properties of BNSs by comparing the findings at various temperatures and SRs. In addition, our study reveals that MLBNSs with an odd number of BN layers show piezoelectric behavior, whereas an even number of BN layers do not show piezoelectric behavior. The piezo- and flexo-electric coefficients of MLBNSs depend on the following aspects: (i) they have an inverse relationship with the number of BN layers, (ii) even or odd numbers of BN layers, and (iii) they disappear completely when the number of BN layers exceeds ten. The present investigation motivates us to develop high-performance and lightweight piezoelectric BN-based NEMS such as nanogenerators, sensors, and actuators, as the existing piezoelectric nanomaterials are brittle, heavy, and toxic. © 2022 Elsevier B.V.