Piezotronics and Piezo‐Phototronics

Abstract

Abstract Most of the current electronics are operated by an externally applied voltage, which tunes the charge transport inside the device. Here, we introduce a new concept that uses the generated potential in a crystal to control the charge transport in the device, which is a new principle for fabricating new electronics that are controlled by externally applied strain/stress. As a result of the polarization of ions in a crystal that has noncentral symmetry in materials such as the wurtzite‐structured ZnO, GaN, and InN, a piezoelectric potential (piezopotential) is created in the crystal by applying a stress. Because of the simultaneous possession of piezoelectricity and semiconductor properties, the piezopotential created in the crystal has a strong effect on the carrier transport at the interface/junction. Piezotronics is about the devices fabricated using the piezopotential as a “gate” voltage to tube/control charge carrier transport at a contact or junction. The piezo‐phototronic effect is about using the piezopotential to control the carrier generation, transport, separation, and/or recombination to improve the performance of optoelectronic devices, such as the photon detector, solar cell, and light‐emitting diode (LED) devices. The objective of this review article is to introduce the fundamentals of piezotronics and piezo‐phototronics. A perspective is given about their potential applications in sensors, human–silicon technology interfacing, microelectromechanical systems (MEMS), nanorobotics, and energy sciences.