Surface waves in a piezoelectric–semiconductor composite structure

Abstract

The present work deals with the propagation of interfacial surface waves in a composite consisting of homogeneous, transversely isotropic, piezoelectric halfspace underlying a thin layer of non-piezoelectric semiconductor material. The mathematical model of the problem is depicted by partial differential equations of motion for the structure and boundary conditions to be satisfied at the interface and free surface of the composite. After obtaining formal wave solution of the model the secular equation that governs the propagation of surface waves in the considered composite structure has been derived in compact form. The numerical solution of secular equation is being carried out for the composites Si–CdSe, Ge–CdSe and Ge–PZT by employing functional iteration method along with irreducible Cardano method using MATLAB programming. The computer simulated results in respect of dispersion curves, attenuation coefficient and specific loss factor of energy dissipation are presented graphically for Si–CdSe composite to illustrate the analytical developments. We have extended our analysis to Ge–CdSe and Ge–PZT composites also. However, to avoid clustering of profiles and also to have clear understanding of the variations, the computer simulated values of phase velocity and attenuation coefficient are presented in tabular form for all three considered composite structures. This work may be useful for designing and construction of surface acoustic wave (SAW) devices and electronics industry.