Prediction of Giant Piezoelectric Properties in Puckered Two-Dimensional Monolayers: SiTe, GeTe, SnTe

Abstract

The discovery of intrinsic piezoelectricity in two-dimensional (2D) nanomaterials (NDs) have increasingly attracted extensive interests for their potential applications in next generation piezoelectric devices. Among a wide range of 2D NDs, monolayer group IV monochalcogenides with black phosphorus like structures have been revealed to have giant piezoelectricity. In this letter, the piezoelectricity of puckered group IV monochalcogenides monolayer NDs, i.e., GeTe, SnTe, and SiTe, is first calculated by using the density functional first-principles theory. The lattice structures, band structures, and elastic properties of these puckered monolayer NDs (GeTe, SnTe, and SiTe) are evaluated based on the PBE functional. ?Berry-phase? polarization theory and density functional perturbation theory (DFPT) are respectively used for calculating the piezoelectric coefficients. It is found that all these puckered monolayer NDs (GeTe, SnTe, and SiTe) exhibit highly strong piezoelectric properties. The calculated superior piezoelectricity makes these puckered monolayer NDs promising applications in the nanoscale flexible electronic and energy transfer devices.