7 research outputs found
Self-Catalyzed AlGaAs Nanowires and AlGaAs/GaAs Nanowire-Quantum Dots on Si Substrates
[Image: see text] Self-catalyzed AlGaAs nanowires (NWs) and NWs with a GaAs quantum dot (QD) were monolithically grown on Si(111) substrates via solid-source molecular beam epitaxy. This growth technique is advantageous in comparison to the previously employed Au-catalyzed approach, as it removes Au contamination issues and renders the structures compatible with complementary metal–oxide–semiconductor (CMOS) technology applications. Structural studies reveal the self-formation of an Al-rich AlGaAs shell, thicker at the NW base and thinning towards the tip, with the opposite behavior observed for the NW core. Wide alloy fluctuations in the shell region are also noticed. AlGaAs NW structures with nominal Al contents of 10, 20, and 30% have strong room temperature photoluminescence, with emission in the range of 1.50–1.72 eV. Individual NWs with an embedded 4.9 nm-thick GaAs region exhibit clear QD behavior, with spatially localized emission, both exciton and biexciton recombination lines, and an exciton line width of 490 μeV at low temperature. Our results demonstrate the properties and behavior of the AlGaAs NWs and AlGaAs/GaAs NWQDs grown via the self-catalyzed approach for the first time and exhibit their potential for a range of novel applications, including nanolasers and single-photon sources
Checked patterned elemental distribution in AlGaAs nanowire branches via vapor–liquid–solid growth†
Hybrid III–V/IV Nanowires: High-Quality Ge Shell Epitaxy on GaAs Cores
The
integration of optically active III–V and electronic-suitable
IV materials on the same nanowire could provide a great potential
for the combination of photonics and electronics in the nanoscale.
In this Letter, we demonstrate the growth of GaAs/Ge core–shell
nanowires on Si substrates by molecular beam epitaxy and investigate
the radial and axial Ge epitaxy on GaAs nanowires in detail. High-quality
core–shell nanowires with smooth side facets and dislocation-free,
sharp interfaces are achieved. It is found that the low shell growth
temperature leads to smoother side facets, while higher shell growth
temperatures lead to more relaxed structures with significantly faceted
sidewalls. The possibility of forming a III–V/IV heterostructure
nanowire with a Ge section development in the axial direction of a
GaAs nanowire using a Ga droplet is also revealed. These nanowires
provide an ideal platform for nanoscale III–V/IV combination,
which is promising for highly integrated photonic and electronic hybrid
devices on a single chip