Physics of imaging p-n junctions by scanning tunneling microscopy and spectroscopy -: art. no. 165307
Physics of imaging p-n junctions by scanning tunneling microscopy and spectroscopy -: art. no. 165307
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DOI：
10.1103/physrevb.67.165307
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发表时间：
2003-04-15
影响因子：
3.7
通讯作者：
Ebert, P
中科院分区：
文献类型：
--
作者：
Jäger, ND;Marso, M;Ebert, P
结合具有原子分辨率的电压依赖扫描隧道显微镜（STM）图像、局域扫描隧道光谱和界面-STM针尖系统中电势分布的模拟，提取了GaAs p-n界面在STM图像中的物理成像机制。结果表明：（i）在正（负）样品电压下，针尖引起的界面附近电势的变化导致p型（n型）层的隧穿特性被拖入界面的耗尽区。(ii)这导致STM图像中耗尽区图像的表观宽度显著减小。(iii)在较小的负样本电压下，出现明显的低压线。凹陷与电子界面直接相关。它是由来自价带和导带的竞争电流贡献的相互作用引起的。这种成像过程的理解使我们能够开发出如何从扫描隧道显微镜图像中提取有关电子界面特性的准确物理数据的方法。
Combined voltage-dependent scanning tunneling microscopy (STM) images with atomic resolution, local scanning tunneling spectroscopy, and simulations of the potential distribution in the interface-STM tip system are used to extract the physical imaging mechanisms of GaAs p-n interfaces in STM images. It is shown that (i) the tip-induced changes of the potential near the interface result in the tunneling characteristics of the p-type (n-type) layer being dragged into the interfaces' depletion region at positive (negative) sample voltage. (ii) This leads to a considerable reduction of the apparent width of the image of the depletion zone in STM images. (iii) At small negative sample voltages, a pronounced depression line appears. The depression is directly correlated with the electronic interface. It arises from the interplay of competing current contributions from the valence and conduction bands. This understanding of the imaging process allows us to develop methods on how to extract accurate physical data about the properties of the electronic interfaces from scanning tunneling microscopy images.