调制掺杂GaAs/AlGaAs2DEG材料持久光电导及子带电子特性研究  

Study of persistent photoconductivity and subband electronic properties of the two-dimensional electron gas in modulation doped GaAs/AlGaAs structure

作　　者：舒强[1] 舒永春[1] 张冠杰[1] 刘如彬[1] 姚江宏[1] 皮彪[1] 邢晓东[1] 林耀望[1,2] 许京军[1] 王占国[1,2] 

机构地区：[1]南开大学泰达应用物理学院,南开大学弱光非线性光子学材料及其先进制备技术教育部重点实验室,天津300457 [2]中国科学院半导体研究所半导体材料科学重点实验室

出　　处：《物理学报》2006年第3期1379-1383,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60476042);长江学者和创新团队发展计划和南开大学泰达学院资助的课题.~~

摘　　要：在掺Si的GaAs/AlGaAs二维电子气(2DEG)结构中,得到μ2K=1·78×106cm2/(V·s)的高迁移率.在低温(2K)和高磁场(6T)的条件下,对样品进行红光辐照,观察到持久光电导(PPC)效应,电子浓度在光照后显著增加.通过整数量子霍尔效应(IQHE)和Shubnikov-de Haas(SdH)振荡的测量,研究了2DEG的子带电子特性.样品在低温光照后2DEG中第一子带和第二子带的电子浓度同时随电子总浓度的增加而增加;而且电子迁移率也明显提高.同时,通过整数霍尔平台的宽度对光照前后电子的量子寿命变短现象作了理论分析.We obtained the high mobility of μ2K = 1.78 × 10^6 cm^2/V· s in Si-doped GaAs/AlGaAs two-dimensional electron gas （2DEG） structures. After the sample was illuminated by a light-emitting diode in magnetic fields up to 6 T at T = 2K, we did observe the persistent photoconductivity effect and the electron density increased obviously. The electronic properties of 2DEG have been studied by Quantum-Hall-effect and Shubnikov-de Haas （SdH） oscillation measurements. We found that the electron concentrations of two subbands increase simultaneity with the increasing total electron concentration, and the electron mobility also increases obviously after being illuminated. At the same time, we also found that the electronic quantum lifetime becomes shorter, and a theoretical explunation is given through the widths of integral quantum Hall plateaus.

关 键 词：二维电子气 量子霍尔效应 SdH振荡 持久光电导效应 

分 类 号：TN304.2[电子电信—物理电子学]