Optical imaging of trion diffusion and drift in GaAs quantum wells
Optical imaging of trion diffusion and drift in GaAs quantum wells
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GaAs 量子阱中 Trion 扩散和漂移的光学成像
DOI：
10.1103/physrevb.68.205304
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发表时间：
2003
影响因子：
3.7
通讯作者：
J. Maan
中科院分区：
文献类型：
--
作者：
F. Pulizzi;D. Sanvitto;P. Christianen;A. Shields;S. Holmes;M. Simmons;D. Ritchie;M. Pepper;J. Maan
The in-plane motion of negatively charged excitons (X-) in modulation-doped GaAs quantum wells (QW's) was studied by means of spatially resolved photoluminescence spectroscopy. In the highest-quality QW's, resonantly excited X- were observed diffusing from the excitation region, characterized by a mobility as high as 6.5x10(4) cm(2) V-1 s(-1), independent of temperature and electron density. Under the application of an electric field in the plane of the QW, X- were found to drift in the direction opposite to the field, whereas neutral excitons (X) do not drift under similar conditions. The results demonstrate that X- can exist as a free quasiparticle in the best-quality samples. The simultaneous motion of nonresonantly excited X and X- was studied as a function of the electron density in the QW. The data reveal that the spatial distribution of X and X- is mainly determined by the motion of X that locally form X-.
