Profiling of the electrical properties of nanowires (NWs) and NW heterocontacts with high spatial resolution is a challenge for any application and advanced NW device development. For appropriate NW analysis, we have established a four-point prober, which is combined in vacuo with a state-of-the-art vapor-liquid-solid preparation, enabling contamination-free NW characterization with high spatial resolution. With this ultrahigh-vacuum-based multi-tip scanning tunneling microscopy (MT-STM), we obtained the resistance and doping profiles of freestanding NWs, along with surface-sensitive information. Our in-system 4-probe STM approach decreased the detection limit for low dopant concentrations to the depleted case in upright standing NWs, while increasing the spatial resolution and considering radial depletion regions, which may originate from surface changes. Accordingly, the surface potential of oxide-free GaAs NW {112} facets has been estimated to be lower than 20 mV, indicating a NW surface with very low surface state density.

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对具有高空间分辨率的纳米线（NW）和NW异质接触的电性能进行性能分析对于任何应用和先进的NW器件开发都是一项挑战。为了进行适当的NW分析，我们建立了一个四点探针，将其真空合并采用最先进的气液固制剂，可实现具有高空间分辨率的无污染NW表征。借助这种基于超高真空的多尖端扫描隧道显微镜（MT-STM），我们获得了独立式NW的电阻和掺杂分布以及表面敏感信息。我们的系统内4探针STM方法将立式NW的耗尽情况下的低掺杂剂浓度检测极限降低了，同时增加了空间分辨率并考虑了可能由表面变化引起的径向耗尽区域。因此，估计无氧化物的GaAs NW {112}刻面的表面电势低于20 mV，表明表面态密度非常低的NW表面。

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