A Tuning Mode of Asymmetric Deformations on the Electric Characteristics of Piezoelectric PN Junctions

Abstract

Influence of asymmetric deformations and the interface polarized charges (IPCs) on the electric characterization of a piezoelectric PN junction is studied in this paper via a fully-coupled model of piezoelectric PN junctions without the depletion layer assumption. A tuning mode of asymmetric deformations on electric characteristics of piezoelectric PN junctions is put forward and the mechanism is analyzed in detail. It is found that the interfacial potential barrier size in the n/p region can be tuned out of sync under the asymmetric deformations. The improved I–V characteristic of a ZnO PN junction is analyzed in detail by applying asymmetric deformation. It is found that the output current can be obviously enhanced by optimizing the recombination rate not only near the interface but also at the loading point. Particularly, the area with evident recombination rate at the interface can be driven to shift a little deviation from there via IPCs, which can be used to avoid the influence of the interface effects (scattering by interface states and defects there) on the mutual conversion between the majority and minority currents. Obviously, the study possesses referential significance to the mechanical tuning on the performance of piezotronic devices.