多个局部温度载荷下压电半导体纤维杆的压电电子学行为分析

温度改变产生的极化电势可对压电半导体结构内的物理量进行有效调控, 这在穿戴电子器件及与温度相关的半导体电子器件中有重要工程应用价值. 本文针对在多个局部均匀温度变化作用下的压电半导体杆结构, 采用一维热压电半导体多场耦合方程, 基于线性化的漂移-扩散(drift-diffusion)电流模型导出了问题的解析解. 以两个局部温度载荷情况为例, 数值分析了局部温度改变对压电半导体内位移、电势、电位移、极化强度、载流子分布等物理场的影响. 对于温度改变较大的情况, 在COMSOL软件的PDE模块中, 采用非线性电流模型, 进行数值模拟. 研究结果表明: 由于两个局部区域的温度改变, 在半导体杆内形成了局部势垒和势阱, 不同的温度改变量和作用区域会产生不同高度/深度的势垒/势阱, 为基于压电半导体的热压电电子学器件结构设计提供了理论指导. 

ANALYSIS OF THE PIEZOTRONIC EFFECT OF A PIEZOELETRIC SEMICONDUCTOR FIBER UNDER MUTIPLE LOCAL TEMPERATURE LOADINGS

The polarization potential resulted from a temperature change through a series coupling effects can significantly change physical fields in piezoelectric semiconductor (PS) structures, which has been found important engineering applications in wearable electronics and temperature-related semiconductor electron devices. Using the one-dimensional multi-field coupling model for thermo-piezoelectric semiconductors, we study the effect of multiple local temperature changes on the behaviors of PS fibers. Based on the linearized current constitutive relations, we obtain the analytical solutions. For instance, a PS fiber under two local temperature changes is numerically studied. The effect of local temperature changes on the distributions of the displacement, potential, electric displacement, polarization and carrier are examined. For large temperature changes, we conduct a nonlinear analysis by COMSOL using the nonlinear current model. The numerical results show that the potential barrier and well produced by the temperature changes through a series of coupling effects depend on the magnitude of the temperature change and the thermal load position. This provides a useful theoretical guidance in the designing of devices.