Faceting of InAs−InSb Heterostructured Nanowires (original) (raw)

Growth mechanism of InAs–InSb heterostructured nanowires grown by chemical beam epitaxy

Journal of Crystal Growth, 2011

We report on the particle diameter dependence of the growth rate of the InSb segment of InAs-InSb heterostructured nanowires grown by chemical beam epitaxy. The analysis of the growth rate reveals that the growth is limited by the Gibbs-Thomson effect and the effect of NW lateral dimensions on the nucleation rate during the layer by layer growth. In the temperature range explored, the surface diffusion of adatoms toward the particle and the growth temperature are not affecting the growth rate.

Growth of InAs/InAsSb heterostructured nanowires

Nanotechnology, 2012

We report the growth of InAs/InAs(1-x)Sb(x) single and double heterostructured nanowires by Au-assisted chemical beam epitaxy. The InAs(1-x)Sb(x) nanowire segments have been characterized in a wide range of antimony compositions. Significant lateral growth is observed at intermediate compositions (x ∼ 0.5), and the nucleation and step-flow mechanism leading to this lateral growth has been identified and described. Additionally, CuPt ordering of the alloy has been observed with high resolution transmission electron microscopy, and it is correlated to the lateral growth process. We also show that it is possible to regrow InAs above the InAsSb alloy segment, at least up to an intermediate antimony composition. Such double heterostructures might find applications both as mid-infrared detectors and as building blocks of electronic devices taking advantage of the outstanding electronic and thermal properties of antimonide compound semiconductors.

Suppression of lateral growth in InAs/InAsSb heterostructured nanowires

Journal of Crystal Growth, 2013

It is well known that a significant lateral growth is observed in the InAsSb sections of InAs/InAsSb heterostructured nanowires (NWs) with intermediate Sb content that prevents the independent control of NW diameter and length. Here we demonstrate that this lateral growth can be suppressed by increasing the growth temperature of the InAsSb segment and by reducing the InAs stem length. Optimized InAsSb sections show good structural and electrical properties. The mechanism driving this reduced lateral growth and its relevance toward the synthesis of highly controlled InAs/InAsSb heterostructured NWs are discussed.

InAs-mediated growth of vertical InSb nanowires on Si substrates

Nanoscale research letters, 2013

In this work, InSb nanowires are grown vertically on Si (111) with metal organic chemical vapor deposition using InAs as seed layer, instead of external metal catalyst. Two groups of InSb nanowires are fabricated and characterized: one group presents Indium droplets at the nanowire's free end, while the other, in contrast, ends without Indium droplet but with pyramid-shaped InSb. The indium-droplet-ended nanowires are longer than the other group of nanowires. For both groups of InSb nanowires, InAs layers play an important role in their formation by serving as a template for growing InSb nanowires. The results presented in this work suggest a useful approach to grow catalyst-free InSb nanowires on Si substrates, which is significant for their device applications.

The self-seeded growth of InAsSb nanowires on silicon by metal-organic vapor phase epitaxy

Journal of Crystal Growth, 2014

We present a study on the growth of InAs 1 À x Sb x alloy nanowires directly on Si (111) substrates via a selfseeded mechanism for the first time. Through varying group V flow rate ratios, InAs 1 À x Sb x nanowires with x ¼from 0 to 0.43 are obtained. It is found that Sb content has a significant effect on the morphology and crystal quality of the formed InAs 1 À x Sb x nanowires. Furthermore, the axial and radial growth rates of the nanowires change in opposite trends with increasing group V flow rate ratio. This indicates that the growth rate of InAs 1 À x Sb x nanowires is ultimately determined by Sb compositions of the nanowires. In addition, the scanning electron microscopy and transmission electron microscopy measurements reveal that the dimensional uniformity and crystal quality of InAsSb nanowires with a small amount of Sb compositions are greatly improved compared to the reference InAs nanowires. The effect mechanism of Sb on the growth of InAs 1 À x Sb x nanowires is clarified, which will be a guide for making high-quality InAs 1 À x Sb x nanowires and relevant heterostructure devices in the future.

Electrical properties and band diagram of InSb-InAs nanowire type-III heterojunctions

Journal of Applied Physics, 2013

The electrical properties of nanowire-based n-InSb-n-InAs heterojunctions were investigated theoretically and experimentally. Analysis of the current-voltage characteristics showed that the current through the heterojunction is caused mostly by generation-recombination processes in the InSb and at the heterointerface. Due to the partially overlapping valence band of InSb and the conduction band of InAs, the second process is fast and activationless. Theoretical analysis showed that, depending on the heterojunction parameters, the flux of non-equilibrium minority carriers may have a different direction, explaining the experimentally observed non-monotonic coordinate dependence of the electron beam induced current.