PN junctions with coupling to bending deformation in composite piezoelectric semiconductor fibers

We demonstrate through a theoretical analysis that a PN junction in a composite fiber consisting of a nonpiezoelectric semiconductor layer between two piezoelectric dielectric layers is electromechanically coupled to the bending deformation of the fiber. This offers new ways for constructing piezotronic device structures. A one-dimensional model based on the macroscopic theory of piezoelectric semiconductors is used in the analysis. The built-in electric potential and electric field, the bending deformation of the fiber, and other electromechanical fields near the junction are obtained. The effects of the doping level, thickness ratio of different layers, and material combination of the composite fiber are examined.