On the Rayleigh wave velocity in n -type piezoelectric semiconductors with enhanced flexoelectricity

Piezoelectric semiconductors like zinc oxide offer giant flexoelectric responses, in addition to their piezoelectric properties and semiconductor characteristics. Departing from conventional models that often disregard flexoelectricity, the research introduces a novel phenomenon by developing a model for the propagation of Rayleigh-type surface waves in a flexoelectric piezoelectric semiconductor (FPSC) halfspace structure, considering second-order strain gradient theory. The superposed solutions of the particle displacement, electric potential, and perturbation in carrier charges due to Rayleigh wave motion have been obtained analytically. Non-classical boundary conditions for the electrically open circuit case are incorporated to establish the dispersion relation for Rayleigh waves. Through numerical examples, the study highlights the substantial impact of diverse flexoelectric coefficients and initial electron concentration on the phase velocity of Rayleigh waves, accompanied by graphical representations that offer insightful visualizations. This extensive inquiry may provide useful insights into understanding Rayleigh-type wave dynamics in microscale semiconductors potentially serving as a guide for developing and implementing in-plane surface acoustic wave (SAW) devices.