Growth and large-scale assembly of InAs/InP core/shell nanowire: effect of shell thickness on electrical characteristics

Huang

et al. 2014

Phys. Status Solidi A

Self Cite

Bandgap engineering is important for realizing high-performance semiconductor devices. In this paper, an investigation on the nanowire diode with a tapered InAs/InP core-shell structure was carried out. The strain distribution along the nanowire can be changed via the shell thickness and the gradient of the tapering. Due to the misfit-strain between InAs/InP, a strain-induced bandgap variation of 0.21 eV along the tapered InAs wire, which results in the rectifying I-V characteristic of the diode, was realized with an InP shell thickness of 6.5 nm. Moreover, due to the optimized shell thickness and strain-induced built-in electric field (including piezoelectric field), a recorded room-temperature electron mobility of 22300 cm 2 V À1 s À1 was achieved. This concept of bandgap engineering would enable the designing of a new kind of nanowire device.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Core-shell nanowire diode based on strain-engineered bandgap

Huang

et al. 2014

Phys. Status Solidi A

Self Cite

“…It has been reported that shell layers would take the same structure as their core NWs during the growth of core-shell NWs, such as InAs/InP [45], GaAs/InAs [31,46], and GaAs/GaAsSb [47]. The structure of shell layers, whether of wurzite or zinc-blende structure, is determined by the maximum change of Gibbs free-energy for wurzite and zinc-blende structures.…”

Section: Resultsmentioning

confidence: 99%

Formation of GaAs/GaSb Core-Shell Heterostructured Nanowires Grown by Molecular-Beam Epitaxy

et al. 2017

Abstract:In this paper, we demonstrated the growth of GaAs/GaSb core-shell heterostructured nanowires on GaAs substrates, with the assistance of Au catalysts by molecular-beam epitaxy. Time-evolution experiments were designed to study the formation of GaSb shells with different growth times. It was found that, by comparing the morphology of nanowires for various growth times, lateral growth was taking a dominant position since GaSb growth began and bulgy GaSb particles formed on the nanowire tips during the growth. The movement of catalyst Au droplets was witnessed, thus, the radial growth was enhanced by sidewall nucleation under the vapor-solid mechanism due to the lack of driving force for axial growth. Moreover, compositional and structural characteristics of the GaAs/GaSb core-shell heterostructured nanowires were investigated by electron microscopy. Differing from the commonly anticipated result, GaSb shells took a wurzite structure instead of a zinc-blende structure to form the GaAs/GaSb wurzite/wurzite core-shell heterostructured nanowires, which is of interest to the research of band-gap engineering. This study provides a significant insight into the formation of core-shell heterostructured nanowires.

“…In fact, it is commonly found that shell layers usually adopt the same structure as their core NWs for different core-shell NWs, such as InAs/InP [41], GaAs/InAs [42], and GaAs/GaAsSb [43], but a detailed explanation for this phenomenon is seldom discussed. Here, based on the VS growth model [44], the change of Gibbs free energy ΔG VS for growing 2D nucleus can be described as: …”

Section: Discussionmentioning

confidence: 99%

Evolution of morphology and microstructure of GaAs/GaSb nanowire heterostructures

Shi¹,

Zhang²,

Lu³

et al. 2016

Nano Online

In this paper, we successfully grow GaAs/GaSb core-shell heterostructure nanowires (NWs) by molecular beam epitaxy (MBE). The as-grown GaSb shell layer forms a wurtzite structure instead of the zinc blende structure that has been commonly reported. Meanwhile, a bulgy GaSb nanoplate also appears on top of GaAs/GaSb core-shell NWs and possesses a pure zinc blende phase. The growth mode for core-shell morphology and underlying mechanism for crystal phase selection of GaAs/GaSb nanowire heterostructures are discussed in detail.