Structural Investigation of InAs-AlInAs and InAs-AlInP Core-Shell Nanowires

Abstract

InAs nanowires were grown on GaAs substrates by the Au-assisted vapour-liquid-solid (VLS) method in a gas source molecular beam epitaxy (GS-MBE) system. Passivation of the InAs nanowires using InP shells proved difficult due to the tendency for the formation of axial rather than core-shell structures. To circumvent this issue, Al${}_x$In${}_{1-x}$As or Al${}_x$In${}_{1-x}$P shells with nominal Al composition fraction of x = 0.20, 0.36, or 0.53 were grown by direct vapour-solid deposition on the sidewalls of the InAs nanowires. Characterization by transmission electron microscopy revealed that the addition of Al in the shell resulted in a remarkable transition from the VLS to the vapour-solid growth mode with uniform shell thickness along the nanowire length. Possible mechanisms for this transition include reduced adatom diffusion, a phase change of the Au seed particle and surfactant effects. The InAs-AlInP core-shell nanowires exhibited misfit dislocations, while the InAs-AlInAs nanowires with lower strain appeared to be free of defects.

References in corpus (5)

• Why does wurtzite form in nanowires of III-V zinc-blende semiconductors?
• Diameter-Dependent Electron Mobility of InAs Nanowires
• Self-directed growth of AlGaAs core-shell nanowires for visible light applications
• Quantum confinement effects in InAs-InP core-shell nanowires
• Multiple Quantum Well AlGaAs Nanowires

Cited by in corpus (4)

• Critical shell thickness for InAs-Al${}_x$In${}_{1-x}$As(P) core-shell nanowires
• Temperature-dependent electron mobility in InAs nanowires
• Trapped charge dynamics in InAs nanowires
• Electron Transport in InAs-InAlAs Core-Shell Nanowires