Atomic-Scale Variability and Control of III-V Nanowire Growth Kinetics

Abstract

In the growth of nanoscale device structures, the ultimate goal is atomic-level precision. By growing III-V nanowires in a transmission electron microscope, we measured the local kinetics in situ as each atomic plane was added at the catalyst-nanowire growth interface by the vapor-liquid-solid process. During growth of gallium phosphide nanowires at typical V/III ratios, we found surprising fluctuations in growth rate, even under steady growth conditions. We correlated these fluctuations with the formation of twin defects in the nanowire, and found that these variations can be suppressed by switching to growth conditions with a low V/III ratio. We derive a growth model showing that this unexpected variation in local growth kinetics reflects the very different supply pathways of the V and III species. The model explains under which conditions the growth rate can be controlled precisely at the atomic level.

Environmental transmission electron microscopy for catalyst materials using a spherical aberration corrector

“…A large chamber around a specimen provides a laboratory for specimen and materials syntheses measurements. Alternatively, it is possible to introduce gas of low pressure into a specimen chamber of conventional TEMs and ultrahigh-vacuum TEMs without any modification of the columns of the TEMs, though the maximum pressure of gas during observation is limited to the order of 10 À 3 Pa [42][43][44].…”

Crossed Ga2O3/SnO2 Multiwire Architecture: A Local Structure Study with Nanometer Resolution

“…15 Techniques such as transmission electron microscopy and powder X-ray diffraction (XRD) have yielded information about these issues. However, in many cases the atomic structural rearrangements are still unexplored.…”

Phase-equilibrium-dominated vapor-liquid-solid mechanism: further evidence

“…Due to its great success and significance, persistent effort has been devoted to exploring the origin of the VLS process over the past half-century. Especially, by applying the advanced in situ microscopic technique, the real-time nucleation and growth process of individual nanowires has been directly observed and the involved kinetics is studied thoroughly [9][10][11][12][13][14][15][16]. Despite such kind of progresses, the precise prediction on nanomaterial synthesis is still a great challenge.…”