Wei Zibo, Wei Peijun, Xu Chunyu, Guo Xiao
Department of Applied Mechanics, University of Science and Technology Beijing, Beijing 100083, China.
J Acoust Soc Am. 2022 Sep;152(3):1883. doi: 10.1121/10.0014179.
The influences of the piezoelectric positive-negative junction (PN junction) between two semiconductors with different doping types on the multi-field coupled wave propagation are studied in the present work. The layered structures of semiconductors are often used in intelligent devices, and the PN junction plays an important role for performance improvement. Due to the migration and diffusion of carriers, the electric potential and concentration of the carrier are graded distribution in the PN junction. This inhomogeneity results in the reflection and transmission of coupled waves, which are the complex of multiple physical fields including the mechanical, electric, and carrier fields. The state transfer equation method is used to obtain the transfer matrix of the PN junction, and the reflection and transmission waves under the plane strain situation are evaluated numerically. The energy fluxes of the reflection and transmission waves are estimated and used to validate the numerical results by the check of energy conservation. It is found that PN junction effects hinder the wave propagation and drastically enhance the reflection ability of the interface, especially, on the coupled carrier waves, and thus are very important and cannot be ignored for the wave propagation problem. The influences of external applied stress and bias electric field are also discussed.
本文研究了不同掺杂类型的两种半导体之间的压电正负结（PN结）对多场耦合波传播的影响。半导体的层状结构常用于智能设备中，PN结对性能提升起着重要作用。由于载流子的迁移和扩散，PN结中载流子的电势和浓度呈梯度分布。这种不均匀性导致了耦合波的反射和透射，耦合波是包括机械场、电场和载流子场在内的多个物理场的复合体。采用状态转移方程法得到PN结的转移矩阵，并对平面应变情况下的反射波和透射波进行了数值评估。估算了反射波和透射波的能量通量，并通过能量守恒检验来验证数值结果。研究发现，PN结效应阻碍波的传播，并显著增强界面的反射能力，特别是对耦合载流子波，因此对于波传播问题非常重要且不可忽视。还讨论了外部施加应力和偏置电场的影响。
