Electron beam induced current in InSb-InAs nanowire type-III heterostructures (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.

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.

Faceting of InAs−InSb Heterostructured Nanowires

Crystal Growth & Design, 2010

We report on the morphology of InAs-InSb heterostructured nanowires grown by Au-assisted chemical beam epitaxy. Using scanning and transmission electron microscopy, along with high angle annular dark field image analysis, we show that the hexagons defining the cross section of the two segments of the nanowires are rotated one with respect to the other by 30°a round the growth direction and that the corners of these hexagons are rounded off by six small facets. Six additional facets that are not parallel to the growth direction are found in the InSb segment at the InAs-InSb interface and are indexed. Finally, the relation between the dimensions of the two segments composing the nanowires is discussed quantitatively.

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.

High-mobility heterostructures based on InAs and InSb: A Monte Carlo study

Journal of Applied Physics, 2009

In this work, by means of Monte Carlo simulations, two different narrow band gap semiconductors, InAs and InSb, and their associated heterostructures, AlSb/InAs and AlInSb/InSb, have been studied. The parameters for the bulk simulations have been optimized in order to correctly reproduce the experimental mobility values. For the correct simulation of the heterostructures, roughness scattering has been included in the model, and its strength has been adjusted to achieve a good agreement with the experimentally measured mobility.

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/InP/InSb nanowires low capacitance n-n heterojunction diodes

Physical Review X, 2011

Nanowire diodes have been realized by employing an axial heterojunction between InAs and InSb semiconductor materials. The broken-gap band alignment (type III) leads to a strong rectification effect when the current-voltage (I-V) characteristic is inspected at room temperature. The additional insertion of a narrow InP barrier reduces the thermionic contribution, which results in a net decrease of leakage current in the reverse bias with a corresponding enhanced rectification in terms of asymmetry in the I-V characteristics. The investigated diodes compare favorably with the ones realized with p-n heterostructured nanowires, making InAs/InP/InSb devices appealing candidates to be used as building blocks for nanowire-based ultrafast electronics and for the realization of photodetectors in the THz spectral range.

Optical and structural investigation of InAs/AlSb/GaSb heterostructures

Optical Materials, 2001

We report on the growth and characterisation of non-intentionally doped InAs/AlSb strained multiple quantum wells (MQWs), grown on GaSb substrates by molecular beam epitaxy (MBE). The structural characterisation is performed using X-ray re¯ectometry (XRR) as a complementary tool to high resolution X-ray diraction (HRXRD) experiments. For the ®rst time in this material system, optical characterisation by photo-induced absorption spectroscopy have been carried out. A strong e 1 3 e 2 p-polarised intersubband absorption is observed with a full width at half maximum of 11 meV at 77 K, showing the good quality of the material. Ó