Scale-Dependent Growth Modes of Selective Area Grown III-V Nanowires

Area of Science:

• Semiconductor Nanostructures
• Materials Science
• Crystal Growth

Background:

• In-plane selective area grown (SAG) nanowires (NWs) combine benefits of vapor-liquid-solid NWs and planar structures.
• Their flexible geometry enables advanced crystal engineering, but growth mechanisms are not fully understood.
• Understanding these mechanisms is crucial for optimizing NW properties and applications.

Purpose of the Study:

• To analyze the growth mechanisms of in-plane SAG nanowires (NWs) using GaAs(Sb) and InGaAs/GaAs(Sb) systems.
• To investigate the influence of material composition, adatom diffusion, and NW dimensions on growth modes.
• To elucidate the role of Sb in modulating growth transitions.

Main Methods:

• Utilized molecular beam epitaxy (MBE) for in-plane SAG nanowire growth.
• Analyzed growth modes including layer-by-layer, step-flow, and layer-plus-island.
• Extracted diffusion lengths of Ga adatoms under As2 for GaAs(Sb) NWs.

Main Results:

• GaAs(Sb) NWs exhibited consistent layer-by-layer growth.
• InGaAs/GaAs(Sb) NWs showed growth mode transitions dependent on InGaAs thickness and NW dimensions.
• Sb was found to potentially inhibit the transition from layer-by-layer to step-flow growth.

Conclusions:

• Different growth modes are achievable in MBE of in-plane SAG NWs on the same substrate.
• The interplay between NW dimensions and growth kinetics significantly impacts crystal engineering.
• This research provides critical insights into controlling NW growth for tailored material properties.