Theory of piezotronics and piezo-phototronics

Piezotronic and piezo-phototronic devices exhibit high performance and have potential applications especially in next-generation self-powered, flexible electronics and wearable systems. In these devices, a strain-induced piezoelectric field at a junction, contact, or interface can significantly modulate the carrier generation, recombination, and transport properties. This mechanism has been studied based on the theory of piezotronics and piezo-phototronics. Simulation-driven materials design and device improvements have been greatly propelled by the finite element method, density functional theory, and molecular dynamics for achieving high-performance devices. Dynamical piezoelectric fields can also control new quantum states in quantum materials, such as in topological insulators, which pave a new path for enhancing performance and for investigating the fundamental physics of quantum piezotronics and piezo-phototronics.