温度梯度对GaN热压电pn结电学性能的影响

Influence of Temperature Gradient on the Electrical Properties of GaN Thermopiezoelectric pn Junction

摘要:

热感应产生的极化电势可以改变压电半导体结构内的力电物理量,这在人工智能、微机电系统(MEMS)中极具应用价值。文章针对温度梯度作用下的氮化镓(GaN)压电pn结,采用二维压电半导体多场耦合方程和精确的热电物理边界条件,数值分析了温度梯度改变对GaN热压电pn结内极化强度、电势、电场、载流子分布及电流等物理场的影响。结果表明:由于温度梯度场和极化电荷之间存在耦合,热压电pn结电学性能对温度梯度高度敏感,由温度改变产生的热感应极化电荷可以有效调节该结构的开启电压和载流子传输特性,这为操控与温度相关的智能异质结器件电流传输提供了新的方法和理论指导。

Abstract:

The polarization potential generated by thermal variation can change the mechanical and electrical physical quantities in the piezoelectric semiconductor structure, which is of valuable application in artificial intelligence and MEMS. By utilizing a developed two-dimensional model together with the accurate thermoelectric physical boundary conditions, it is systematically investigated the temperature gradient-dependent physical fields such as polarization, electric potential, electric field, carrier distribution and current in a GaN piezoelectric pn junction. It is found that, due to the coupling between the thermal-gradient fields and polarization charges, the electromechanical field of a piezoelectric pn junction has a quick response to thermal-gradient. Furthermore, gate voltage and carrier transport characteristics can be effectively tuned with thermal-induced and piezoelectric charges. This may provide an alternative approach and theoretical guidance to manipulate the carrier transport in intelligent heterojunction devices.