Park Kidong, Lee Jinha, Kim Doyeon, Seo Jaemin, Kim Jundong, Ahn Jae-Pyoung, Park Jeunghee
Department of Chemistry, Korea University, Sejong 339-700, Korea.
Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791, Korea.
ACS Omega. 2019 Feb 12;4(2):3098-3104. doi: 10.1021/acsomega.8b03548. eCollection 2019 Feb 28.
One-dimensional semiconductor nanowires often contain polytypic structures, owing to the co-existence of different crystal phases. Therefore, understanding the properties of polytypic structures is of paramount importance for many promising applications in high-performance nanodevices. Herein, we synthesized nanowires of typical III-V semiconductors, namely, gallium phosphide and gallium arsenide by using the chemical vapor transport method. The growth directions ([111] and [211]) could be switched by changing the experimental conditions, such as H gas flow; thus, various polytypic structures were produced simultaneously in a controlled manner. The nanobeam electron diffraction technique was employed to obtain strain mapping of the nanowires by visualizing the polytypic structures along the [111] direction. Micro-Raman spectra for individual nanowires were collected, confirming the presence of wurtzite phase in the polytypic nanowires. Further, we fabricated the photodetectors using the single nanowires, and the polytypic structures are shown to decrease the photosensitivity. Our systematic analysis provides important insight into the polytypic structures of nanowires.
一维半导体纳米线由于不同晶相的共存，常常包含多型结构。因此，了解多型结构的性质对于高性能纳米器件中许多有前景的应用至关重要。在此，我们通过化学气相传输法合成了典型的III-V族半导体纳米线，即磷化镓和砷化镓。生长方向（[111]和[211]）可以通过改变实验条件（如氢气流量）来切换；因此，各种多型结构得以以可控的方式同时产生。利用纳米束电子衍射技术，通过沿[111]方向可视化多型结构来获得纳米线的应变映射。收集了单个纳米线的显微拉曼光谱，证实了多型纳米线中纤锌矿相的存在。此外，我们使用单根纳米线制造了光电探测器，结果表明多型结构会降低光电灵敏度。我们的系统分析为纳米线的多型结构提供了重要的见解。
