High performance piezotronic devices based on non-uniform strain

Publication date: June 2019Source: Nano Energy, Volume 60Author(s): Yaming Zhang, Gongwei Hu, Yan Zhang, Lucy Li, Morten Willatzen, Zhong Lin WangAbstractPiezotronic and piezophototronic devices have attracted increasing interests in self-powered sensor, piezotronic logic units and flexible energy-harvesting devices. The carrier transport characteristics can be effectively tuned by the piezoelectric charges induced by an externally applied strain, which has been extensively investigated for a uniform strain case. However, a non-uniform strain can induce a giant piezoelectric field at the interface to significantly enhance the piezotronic effect. In this paper, we propose a model that a mechanical stress is gradient distributed along a piezoelectric-semiconductor material. The electric properties of piezotronic p-n junction with non-uniform strain has been simulated by using the finite element method, including the current-voltage characteristics and carrier concentration. The piezotronic p-n junction involving strain gradient possesses ultrahigh sensitivity (the gauge factor over 2500) due to the enhancement of piezoelectric constant. This investigation further broadens the fundamental theory of piezotronics and offers guidance for designing ultrahigh performance piezotronic devices.Graphical abstractThe piezotronic devices based on non-uniform strain can have ultrahigh performance. The gauge factor of the novel piezotronic p-n junction based on a non-uniform strain can reach...

Source: Nano Energy - April 10, 2019 Category: Nanotechnology Source Type: research