Investigation of Acoustic Waves in a Piezoelectric Layer in between Semiconducting Halfspaces

In this analysis, we have examined the acoustic wave propagation in a layer of piezoelectric material sandwiched between two n-type halfspaces of semiconductor material. The equations describing the motion, Gauss law for piezoelectric and the electron diffusion equation for semiconductor together with the interfacial boundary conditions for the two materials forms the mathematical model of the problem. The characteristic equation describing the wave propagation for symmetric and asymmetric modes was obtained after obtaining the analytical expressions for different field quantities governing the wave motion in compact form. With the irreducible Cardano method, the complex characteristic equation was solved numerically using functional iteration method. The simulation of the results was done by employing MATLAB software for the following heterostructures: (i) Si-PZT-Si (ii) Ge-PZT-Ge to obtain the dispersion curve for phase velocity, attenuation of waves and specific loss factor of energy dissipation in the material for both symmetric as well as asymmetric modes of propagation. The characteristics of considered layered structures are significantly influenced by properties of the inserted layer. The study of acoustic waves in piezoelectric layer sandwiched in semiconductor half-spaces is very important to understand the effect of material constituents on the propagating waves which modifies the characteristics of these waves. These studies are helpful in fabrication of acoustic wave devices such as sensors, actuators, transducers etc.