Al_xGa_(1-x)As/GaAs异质结中电子迁移率的压力效应  

Pressure Effect on Electronic Mobility in Quasi-Two-Dimensional Al_xGa_(1-x)As/GaAs Heterojunction Systems

作　　者：白鲜萍[1] 班士良[1] 

机构地区：[1]内蒙古大学理工学院物理系,呼和浩特010021

出　　处：《Journal of Semiconductors》2005年第12期2422-2427,共6页半导体学报（英文版）

基　　金：国家自然科学基金(批准号:60166002);内蒙古自治区优秀学科带头人计划资助项目~~

摘　　要：对AlxGa1-xAs/GaAs半导体单异质结系统,引入有限高势垒与考虑导带弯曲的真实势,同时计入电子对异质结势垒的隧穿,利用变分法和记忆函数方法讨论在界面光学声子和体纵光学声子的散射下,异质结界面附近电子迁移率随温度的变化关系及其压力效应.结果显示:电子迁移率随温度、压力的增加而减小;且两种声子的散射作用均随压力增强,界面光学声子的变化幅度更大.因此,在讨论压力的情形下,界面光学声子的作用不容忽略.A variational method and a memory function approach are adopted to investigate electronic mobility and pressure effect in quasi-two-dimensional heterojunction systems by considering optical phonon modes （including bulk longitudinal optical （LO） phonons and interface optical（IO） phonons） and a realistic heterojunction potential model, which includes the influences of finite potential barrier and energy band bending. Meanwhile, the tunnelling of electrons into the barrier is taken into account. A numerical calculation is performed for the AlxGa1-x As/GaAs heterojunctions. The results show that electron mobility obviously decreases as the temperature and pressure incrense, the contribution to electron mobility from IO phonon scattering under pressure becomes more obvious than that from LO phonon scattering. Under pressure, the effect of IO phonon scattering cannot be neglected in further works.

关 键 词：异质结 电子迁移率 压力效应 

分 类 号：TN304[电子电信—物理电子学]