Photoinduced Current Properties of InAs-Covered GaAs Studied by Scanning Tunneling Microscopy.
Photoinduced Current Properties of InAs-Covered GaAs Studied by Scanning Tunneling Microscopy.
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通过扫描隧道显微镜研究 InAs 覆盖的 GaAs 的光生电流特性。
DOI：
10.1143/jjap.38.3871
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发表时间：
1999
影响因子：
1.5
通讯作者：
Takuji Takahashi
中科院分区：
文献类型：
--
作者：
H. Yamamoto;I. Kamiya;Takuji Takahashi
我们进行了同步成像的光生电流和形貌的InAs覆盖的GaAs表面上的扫描隧道显微镜（STM）调制激光照射下，调查量子点和润湿层之间的电子性质的差异。我们还进行了时间分辨隧道电流测量，以澄清其表面光致效应的起源。我们观察到一个尖峰的瞬态电流，由表面耗尽层中的内置场的光生载流子分离。在900 Hz的斩波频率下获得了主要源自表面耗尽的光生电流的图像，并且在该频率下观察到的光生电流图像和电流瞬变表明，在点下比在润湿层下更抑制表面耗尽。
We performed simultaneous imaging of photoinduced current and topography on an InAs-covered GaAs surface by scanning tunneling microscopy (STM) under modulated laser irradiation to investigate the difference in the electronic properties between quantum dots and a wetting layer. We also performed time-resolved tunneling current measurements to clarify the origin of the photoinduced effects on its surface. We observed a spiky transient current, resulting from photocarrier separation by a built-in field in the surface depletion layer. Images of the photoinduced current mainly originating from the surface depletion were obtained at a chopping frequency of 900 Hz, and both the photoinduced current images and the current transients observed at this frequency reveal that the surface depletion is more suppressed under the dots than under the wetting layer.