Crawford Samuel C, Ermez Sema, Haberfehlner Georg, Jones Eric J, Gradečak Silvija
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Nanotechnology. 2015 Jun 5;26(22):225604. doi: 10.1088/0957-4484/26/22/225604. Epub 2015 May 13.
Diameter-modulated nanowires can be used to impart unique properties to nanowire-based devices. Here, diameter modulation along Au-seeded GaAs nanowires was achieved by varying the flux of the III and V precursors during growth. Furthermore, three different types of [111]B-oriented nanowires were observed to display distinct differences in diameter modulation, growth rate, and cross-sectional shape. These differences are attributed to the presence of multiple distinct Au-Ga seed particle phases at the growth temperature of 420 °C. We show that the diameter modulation behavior can be modified by the growth conditions during nanowire nucleation, including temperature, V/III ratio, substrate orientation, and seed particle size. These results demonstrate the general viability of flow-controlled diameter modulation for compound semiconductors and highlight both opportunities and challenges that can arise from using compound-forming alloys to seed nanowire growth.
直径调制的纳米线可用于赋予基于纳米线的器件独特的性能。在此，通过在生长过程中改变III族和V族前驱体的通量，实现了沿金籽晶砷化镓纳米线的直径调制。此外，观察到三种不同类型的[111]B取向纳米线在直径调制、生长速率和横截面形状方面表现出明显差异。这些差异归因于在420℃的生长温度下存在多个不同的金-镓籽晶颗粒相。我们表明，纳米线成核过程中的生长条件，包括温度、V/III比、衬底取向和籽晶颗粒尺寸，可以改变直径调制行为。这些结果证明了流量控制直径调制对于化合物半导体的普遍可行性，并突出了使用形成化合物的合金作为纳米线生长籽晶可能带来的机遇和挑战。
