Multi-Probe Electrical Characterization of Nanowires for Solar Energy Conversion
Multi-Probe Electrical Characterization of Nanowires for Solar Energy Conversion
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DOI：
10.1109/jphotov.2019.2894065
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发表时间：
2019-02
影响因子：
3
通讯作者：
A. Nägelein;C. Timm;M. Steidl;P. Kleinschmidt;T. Hannappel
中科院分区：
文献类型：
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作者：
A. Nägelein;C. Timm;M. Steidl;P. Kleinschmidt;T. Hannappel
催化剂辅助的气-液-固纳米线（NW）生长提供了制备通用的轴向和径向III-V族同质和异质结构的机会，其联合收割机结合了多种科学和经济效益，包括在创新的太阳能转换中的应用。对于NW异质接触的必要和合适的光电分析，我们已经建立了一个复杂的多尖端扫描隧道显微镜（STM）用作四点探针，这是在真空中与最先进的制备相结合，使独立的NW的个别表征，制备后没有污染，并具有最高的空间分辨率。我们应用上级能力的超高真空为基础的多尖端STM进行深入研究的砷化镓NW结构，包括一个轴向的p-n结。二极管的两点和四点I-V特性被非破坏性地记录，从而能够确定局部理想因子。在不同NW位置的四点探针测量导致轴向电阻分布，允许计算p型和n型掺杂部件的掺杂浓度。在p-n结周围，检测到一个500 nm宽的低电导区，表明生长过程中掺杂剂的补偿效应。通过记录电子束感应电流图像，确认电荷分离接触的位置。
Catalysis-assisted vapor–liquid–solid nanowire (NW) growth offers opportunities to prepare versatile, axial, and radial III–V homo- and hetero-structures, which combine multiple scientific and economic benefits including applications in innovative solar energy conversion. For an essential and suitable optoelectronic analysis of NW heterocontacts, we have established a sophisticated multi-tip scanning tunneling microscope (STM) used as a four-point prober, which is in vacuo combined with state-of-the-art preparation, enabling an individual characterization of free-standing NWs with no contamination after preparation and with highest spatial resolution. We apply the superior capabilities of the ultra-high-vacuum-based multi-tip STM to perform an in-depth study of gallium arsenide NW structures, incorporating an axial p-n junction. Two- and four-point I–V characteristics of the diode are recorded non-destructively, enabling the determination of a local ideality factor. Four-point-probe measurements at different NW positions result in an axial resistance profile, allowing the calculation of the doping concentration of p- and n-doped parts. Around the p-n junction, a 500-nm-width region of low conductance was detected, indicating a compensation effect of dopants during growth. By recording electron-beam-induced current images, the position of the charge separating contact was confirmed.