title: Fundamental theory of piezotronics.
abstract: Due to polarization of ions in crystals with noncentral symmetry, such as ZnO, GaN, and InN, a piezoelectric potential (piezopotential) is created in the crystal when stress is applied. Electronics fabricated using the inner-crystal piezopotential as a gate voltage to tune or control the charge transport behavior across a metal/semiconductor interface or a p-n junction are called piezotronics. This is different from the basic design of complimentary metal oxide semiconductor (CMOS) field-effect transistors and has applications in force and pressure triggered or controlled electronic devices, sensors, microelectromechanical systems (MEMS), human-computer interfacing, nanorobotics, and touch-pad technologies. Here, the theory of charge transport in piezotronic devices is investigated. In addition to presenting the formal theoretical frame work, analytical solutions are presented for cases including metal-semiconductor contact and p-n junctions under simplified conditions. Numerical calculations are given for predicting the current-voltage characteristics of a general piezotronic transistor: metal-ZnO nanowire-metal device. This study provides important insight into the working principles and characteristics of piezotronic devices, as well as providing guidance for device design.
authors.affiliation: School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, 30332-0245, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhong Lin
authors.initials: ZL
authors.lastname: Wang
mesh_terms: D008670:Metals / Q000737:chemistry; D008962:Models, Theoretical; D053770:Nanowires / Q000737:chemistry; D012666:Semiconductors; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D008670:Metals; D015034:Zinc Oxide