Executive Summary : | Piezoelectricity in 2D materials was first predicted theoretically in 2012 and experimentally confirmed in 2014. And since, there has been a boom in scientific and technological interest in piezoelectricity in graphene-like two-dimensional (2D) materials with broken inversion symmetry. Avenues to induce or improve piezoelectricity in 2D materials is being explored. Unfortunately, most 2D materials discovered to date exhibit mostly in-plane piezoelectricity; nonetheless, for device-based applications, out-of-plane piezoelectricity is highly desired and sought after. Certain 2D structures, Janus structures, and interfaces of 2D structures have been found to show out-of-plane piezoelectricity. However, it's still in its infancy and the underlying mechanism needs a much deeper insight at an atomic level for rapid advancement in this field. The significance of out-of-plane piezoelectricity lies in its ability to induce strain-tunable gating effects in nanoelectronics and nanotransistors, making it a highly sought-after feature for futuristic devices and technologies. By shedding light on this aspect of 2D materials, our research will contribute towards unlocking their full potential in multifunctional nanodevice and nano-FET applications. |