中文摘要：

在掺Si的GaAs/AlGaAs二维电子气（2DEG）结构中，得到μ2K=1．78×10^6cm^2／（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的于带电子特性．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．

英文摘要：

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.