Piezoelectric Response at Nanoscale

Abstract

Considerable efforts were invested to study the piezoelectricity at the nanoscale, which serves as a physical basis for a wide range of smart nanodevices and nanoelectronics. This chapter reviews the recent progress in characterizing the effective piezoelectric property in a nanoworld and the influence of the piezoelectric effect on the mechanical responses of nanoscale structures. Extremely strong piezoelectric responses of piezoelectric nanomaterials were reported in experiments, and the size dependence was observed in atomistic simulations. Attempts were also made to reveal the physics behind these unique features, but the universal theory has not yet been established. Among the proposed mechanisms, the theory of surface piezoelectricity is widely accepted and thus used to derive two effective piezoelectric coefficients (EPCs) for investigating the effect of piezoelectricity on (1) stress or strain and (2) the effective elastic moduli of piezoelectric nanomaterials. The EPCs are found to be size-dependent and also deformationselective. The obtained results also show that at the nanoscale the surface piezoelectricity can enhance the piezoelectric potential of nanostructures when subjected to a static deformation. In addition, the intrinsic loss of oscillating piezoelectric nanostructures can be mitigated through the piezoelectric effect at the nanoscale.