Propagation characteristics of shear horizontal waves in piezoelectric semiconductor nanoplates incorporating surface effect

Elastic wave-based devices made of piezoelectric semiconductors (PSs) find wide applications in modern scientific and technological fields. Elastic waves propagating in PS nanostructures have a rich variety of propagation characteristics due to the interaction between deformation, polarization, and charge carrier, as well as the influence of surface effect. Based on the Gurtin-Murdoch surface model, we conduct an analysis of horizontally polarized shear (SH) waves propagating in an infinite n-type PS plate with nano-thickness in this paper. For the open-circuit and electrically isolated boundary conditions, the analytical frequency and phase velocity spectrum relations and cut-off frequencies of SH waves with anti-symmetric and symmetric modes are presented. The influence of the surface effect, initial electron concentration, and thickness of the PS plate on the propagation characteristics of SH waves, such as frequency spectrum, phase velocity, and cut-off frequency, are elaborated in detail. Numerical results show that propagation characteristics of SH waves are size-dependent, and the macroscopic effective shear rigidity is softened at the nanoscale due to surface effect, which thus leads to the reduction of the frequency and phase velocity of SH waves. Moreover, the propagation characteristics of SH waves can be manipulated by changing the initial electron concentration.