Surface photovoltage on Si(111)‐(7×7) probed by optically pumped scanning tunneling microscopy
Surface photovoltage on Si(111)‐(7×7) probed by optically pumped scanning tunneling microscopy
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光泵扫描隧道显微镜探测Si(111)-(7×7)表面光电压
DOI：
10.1116/1.576501
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
K. Markert
中科院分区：
文献类型：
--
作者：
R. Hamers;K. Markert
利用扫描隧道显微镜（STM）结合光激发技术研究了Si（111）-（7×7）表面的空间分辨非平衡电子输运过程。光激发载流子在亚表面空间电荷区分离，产生表面光电压，使用STM针尖作为电位计检测。虽然Si（111）-（7×7）的有序区域上的光电压是均匀的，但几乎所有缺陷附近都观察到强烈的下降。还观察到光电压对照明强度的功能依赖性的差异。光电压的空间依赖性主要来自局部表面复合率的空间变化。
Scanning tunneling microscopy (STM) is combined with optical excitation techniques to probe spatially resolved, nonequilibrium electronic transport processes at Si(111)‐(7×7) surface. Photoexcited carriers separate in the subsurface space‐charge region, producing a surface photovoltage which is detected using the STM tip as a potentiometer. While the photovoltage is uniform on well‐ordered regions of Si(111)‐(7×7), strong decreases are observed near virtually all defects. Differences in the functional dependence of the photovoltage on the illumination intensity are also observed. The spatial dependence of the photovoltage primarily results from spatial variations in the local surface recombination rate.