Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, University of Science and Technology Beijing, Beijing 100083, China; Department of Applied Mechanics, University of Science and Technology Beijing, Beijing 100083, China.
Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, University of Science and Technology Beijing, Beijing 100083, China; Department of Applied Mechanics, University of Science and Technology Beijing, Beijing 100083, China.
Ultrasonics. 2019 Feb;92:68-78. doi: 10.1016/j.ultras.2018.09.009. Epub 2018 Sep 20.
The dispersion and attenuation features of the multi-physical fields coupled waves propagating in an infinite piezoelectric semiconductor and the reflection problem at a boundary which is mechanically free, electrically insulation and the dielectrically open circuit are studied in this paper. Different from the classic dielectric piezoelectric medium, there are four kinds of coupled elastic waves, i.e. the quasi-longitudinal wave (QP), the quasi-traverse wave (QSV), the electric-acoustic wave (EA) and the electron or hole carriers wave (CP), in a piezoelectric semiconductor. The influences of the steady carrier density and biasing electric field upon the dispersion and attenuation features of these coupled elastic waves and the reflection amplitude ratios are studied numerically. The energy flux of each wave and the interaction energy fluxes among all waves are also calculated, and the energy flux balance is checked. It is found that the piezoelectric semiconductor behaves like the viscoelastic solid to carry a decaying wave. The steady carrier density and biasing electric field have significant influences on the dispersion and attenuation features and can be used to regulate the propagation of the coupled elastic waves.
本文研究了在无限压电半导体中传播的多物理场耦合波的弥散和衰减特性，以及机械自由、电绝缘和介电开路边界的反射问题。与经典介电压电介质不同，在压电半导体中有四种类型的耦合弹性波，即准纵波（QP）、准横波（QSV）、电声波（EA）和电子或空穴载流子波（CP）。数值研究了稳态载流子密度和偏置电场对这些耦合弹性波的弥散和衰减特性以及反射幅度比的影响。还计算了各波的能流和所有波之间的相互作用能流，并检查了能量流平衡。结果表明，压电半导体表现为粘弹性固体，携带衰减波。稳态载流子密度和偏置电场对弥散和衰减特性有显著影响，可以用来调节耦合弹性波的传播。
