Electromechanical interactions in a composite plate with piezoelectric dielectric and nonpiezoelectric semiconductor layers

We study interactions between mechanical loads and distributions of charge carriers as well as current densities in the bending of a sandwich plate with a piezoelectric dielectric layer between two nonpiezoelectric semiconductor layers. A set of two-dimensional plate equations is derived from the underlying three-dimensional macroscopic theory of piezoelectric semiconductors when the plate is in bending with shear deformation under transverse mechanical loads. It is shown that the distribution and motion of the mobile charges in the semiconductor layers are sensitive to and can be manipulated by mechanical loads. In particular, local electric potential barriers/wells form when the plate is under local mechanical loads, and the potential barriers/wells affect the distributions of the current densities in the semiconductor layers. Thus the sandwich plate exhibits couplings between mechanical loads and the distribution/motion of mobile charges and can be used for electromechanical semiconductor devices with broad applications in sensing and transduction.