Ji Xianghai, Yang Xiaoguang, Yang Tao
Key Laboratory of Semiconductor Materials Science, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, People's Republic of China.
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Nanoscale Res Lett. 2017 Dec;12(1):428. doi: 10.1186/s11671-017-2207-5. Epub 2017 Jun 26.
We report the first self-catalyzed growth of high-quality GaSb nanowires on InAs stems using metal-organic chemical vapor deposition (MOCVD) on Si (111) substrates. To achieve the growth of vertical InAs/GaSb heterostructure nanowires, the two-step flow rates of the trimethylgallium (TMGa) and trimethylantimony (TMSb) are used. We first use relatively low TMGa and TMSb flow rates to preserve the Ga droplets on the thin InAs stems. Then, the flow rates of TMGa and TMSb are increased to enhance the axial growth rate. Because of the slower radial growth rate of GaSb at higher growth temperature, GaSb nanowires grown at 500 °C exhibit larger diameters than those grown at 520 °C. However, with respect to the axial growth, due to the Gibbs-Thomson effect and the reduction in the droplet supersaturation with increasing growth temperature, GaSb nanowires grown at 500 °C are longer than those grown at 520 °C. Detailed transmission electron microscopy (TEM) analyses reveal that the GaSb nanowires have a perfect zinc-blende (ZB) crystal structure. The growth method presented here may be suitable for other antimonide nanowire growth, and the axial InAs/GaSb heterostructure nanowires may have strong potential for use in the fabrication of novel nanowire-based devices and in the study of fundamental quantum physics.
我们报道了首次在硅（111）衬底上利用金属有机化学气相沉积（MOCVD）在砷化铟（InAs）茎上自催化生长高质量的锑化镓（GaSb）纳米线。为了实现垂直的InAs/GaSb异质结构纳米线的生长，使用了三甲基镓（TMGa）和三甲基锑（TMSb）的两步流速。我们首先使用相对较低的TMGa和TMSb流速，以在细InAs茎上保留镓液滴。然后，提高TMGa和TMSb的流速以提高轴向生长速率。由于在较高生长温度下GaSb的径向生长速率较慢，在500°C生长的GaSb纳米线比在520°C生长的纳米线直径更大。然而，关于轴向生长，由于吉布斯-汤姆逊效应以及随着生长温度升高液滴过饱和度降低，在500°C生长的GaSb纳米线比在520°C生长的更长。详细的透射电子显微镜（TEM）分析表明，GaSb纳米线具有完美的闪锌矿（ZB）晶体结构。这里提出的生长方法可能适用于其他锑化物纳米线的生长，并且轴向InAs/GaSb异质结构纳米线在用于制造新型基于纳米线的器件以及基础量子物理学研究方面可能具有强大的潜力。
