本征GaAs中电子自旋极化对电子复合动力学的影响研究  

Effect of spin polarization on electron recombination dynamics in bulk intrinsic GaAs

作　　者：滕利华[1] 余华梁[1] 黄志凌[1] 文锦辉[1] 林位株[1] 赖天树[1] 

机构地区：[1]中山大学光电材料与技术国家重点实验室,物理科学与工程学院,广州510275

出　　处：《物理学报》2008年第10期6593-6597,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60490295,60678009,10674184);高等学校博士学科点专项科研基金(批准号:20050558030)资助的课题~~

摘　　要：采用时间分辨圆偏振光和线偏振光抽运-探测光谱,研究了9.6 K温度下本征GaAs中自旋极化电子与非极化电子的复合动力学及其随光子能量演化.发现自旋极化对电子复合动力学具有显著影响.仅在导带底附近测量时,两种方法测试到的复合寿命一致,而在高过超能量电子态测量时,两种方法测试到的复合寿命不一致.指出时间分辨法拉第光谱中,用于反演求解电子自旋相干寿命的电子复合寿命应该使用圆偏振光抽运-探测获得的复合寿命,而不是线偏振光抽运-探测获得的寿命.理论计算与实验结果吻合较好.Time-resolved circularly polarized and linearly polarized pump-probe spectroscopies are used to study the recombination dynamics of spin-polarized and spin-nonpolarized electrons as well as its evolution with photon energy for an intrinsic GaAs at 9.6 K. It is found that the spin polarization has a significant influence on the electron recombination dynamics. The spectroscopic measurements give the same recombination lifetime only when measured near the bottom of the conduction band, but different recombination lifetimes were measured in higher excess-energy states. It is pointed out that the recombination lifetime measured by circularly polarized pump-probe spectroscopy, rather than that measured by linearly-polarized pump-probe spectroscopy, should be used to solve for the lifetime of electron-spin coherence from time-resolved Faraday spectroscopic data. The theoretical calculation agrees well with the experimental results.

关 键 词：圆偏振光抽运-探测光谱 自旋量子拍 自旋极化 GAAS 

分 类 号：O471[理学—半导体物理]