Large-Composition-Range Pure-Phase Homogeneous InAs_1-Sb Nanowires

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Narrow bandgap InAs$_{1-x}$Sb$_x$ nanowires are promising for infrared detectors, transistors, and quantum computing.
• Achieving desired applications requires precise control over nanowire composition and crystal structure.
• Fabricating large-composition-range, pure-phase, homogeneous InAs$_{1-x}$Sb$_x$ nanowires presents a significant challenge.

Purpose of the Study:

• To report the first growth of large-composition-range, stemless InAs$_{1-x}$Sb$_x$ nanowires on Si (111) substrates.
• To investigate the conditions necessary for obtaining pure-phase InAs$_{1-x}$Sb$_x$ nanowires.
• To characterize the composition uniformity and electronic properties of the grown nanowires.

Main Methods:

• Molecular beam epitaxy (MBE) for nanowire growth.
• Control of antimony content, nanowire diameter, and growth direction.
• Energy dispersive spectroscopy (EDS) for compositional analysis.
• Field-effect measurements for electrical characterization.

Main Results:

• Successfully grew large-composition-range InAs$_{1-x}$Sb$_x$ nanowires (0 ≤ x ≤ 0.63) using MBE.
• Demonstrated that pure-phase nanowires can be achieved by controlling growth parameters.
• EDS confirmed uniform antimony distribution axially and radially, with no core-shell structures.
• Measured high conductivity and electron mobilities up to 4200 cm$^2$ V$^{-1}$ s$^{-1}$ at 7 K.

Conclusions:

• Established a method for fabricating homogeneous InAs$_{1-x}$Sb$_x$ nanowires with a wide composition range.
• The findings support the potential of these nanowires for advanced optoelectronic and electronic devices.
• This work provides a foundation for developing InAs$_{1-x}$Sb$_x$ nanowire-based quantum devices.