Flexoelectricity in two-dimensional boron nitride and other materials

2D materials can easily achieve huge strain gradients because of their atomic thickness, which is challenging with bulk materials. This characteristic offers a unique platform for researchers to explore the coupling between strain gradients and electrical polarizations (flexoelectricity). The flexoelectric properties of boron nitride (BN) monolayers are studied due to their prospective uses in harsh environments. Although hexagonal BN is an isoelectronic isomorph of graphene, it has more nonlinearity and higher flexoelectric coefficients than graphene. In this chapter, we have discussed the general theories of estimating the BN’s flexoelectric potential. The flexoelectric effect can be enhanced by various techniques, including defects, zigzag, armchair, doping, and multilayer BN, which are explained in detail. Finally, flexoelectricity in other 2D materials is also considered for analysis.