Flexoelectric Effects in Corrugated Boron Nitride Nanoribbons

Hexagonal boron nitride (h-BN) monolayer is an isostructural analogue to graphene and promising dielectric. Inspired by recent experimental reports, we focus on suspended and corrugated boron nitride nanoribbons (BNRs) as model systems, and report an intriguing flexoelectric polar effect using a series of ab initio-based density functional theory and tight binding calculations. Our results decode various synergies of the complex flexoelectrical properties including the role of corrugation height, structural deformation, and orbital mixing in corrugated BNRs. We demonstrate structural deformation of BNRs significantly contribute to the magnitude of electric dipole moment and bandgap closing, converting the insulating BNRs to semiconductors. This important finding, combined with the fundamental insights into the nature of electromechanical coupling, provides key hypotheses for design and modulation of novel nanoelectronic and nanophotonic devices.