Growth of dilute nitride GaAsN/GaAs heterostructure nanowires on Si substrates

Abstract

The concept of band engineering dilute nitride semiconductors into nanowires is introduced. Using plasma-assisted molecular beam epitaxy, dilute nitride GaAsN/GaAs heterostructure nanowires are grown on silicon (111) substrates. Growth of the nanowires under high As overpressure results in a regular wire diameter of 350 nm with a length exceeding 3 μm. The GaAsN/GaAs nanowires show characteristics including favorable vertical alignment, hexagonal cross-sectional structure with {110} facets, regions of wurtzite and zinc-blende phases, and a core-shell-type heterostructure. The nanowires are composed of GaAsN shells containing up to 0.3% nitrogen surrounding GaAs cores. Panchromatic cathodoluminescence images show intensity modulation along the length of the nanowires that is possibly related to the interfaces of wurtzite/zinc-blende regions. Photoluminescence with peak wavelengths between 870 and 920 nm is clearly observed at room temperature. The spectral red shift depends on the amount of introduced nitrogen. These results reveal a method for precise lattice and band engineering of nanowires composed of dilute nitride semiconductors.

N -induced Quantum Dots in GaAs/Ga(N,Jansson1, Ishikawa2, Chen3 et al. 2018Phys. Rev. Applied62130View full textAdd to dashboardCite

“…The GaAs core is first grown using vapor-liquid-solid growth, on which the Ga(N, As) shell is formed via step-mediated growthsee Ref. [29] for a detailed description of the NW growth. Nitrogen composition in the Ga(N, As) shell is controlled by varying the N flux supplied from a N-plasma source and is estimated [30] as being 0.1% and 0.5%, based on a detailed analysis of the temperature-dependent PL results within the framework of the band anticrossing model [31].…”

Strongly polarized quantum-dot-like light emitters embedded in GaAs/GaNAs core/shell nanowires

“…35 Cross-sectional TEM images of the GaAs/GaNAs core/shell NWs can be found in ref. 34. As a reference, we also grew GaAs/GaAs NW structures that were produced under the identical conditions as the GaAs/GaNAs NWs but without N flux irradiation.…”

“…[28][29][30][31] With increasing N compositions above the doping limit, on the other hand, the localized states are caused by short-and longrange potential fluctuations in the bandgap energy due to alloy disorder 32,33 that is amplified in the N-containing alloys because of the giant bandgap bowing effect. 20 Most recently GaNAs alloys with superior optical quality were grown in 1D geometry as a shell layer in GaAs/GaNAs core/shell NWs, [34][35][36] providing the opportunity to combine the attractive physical properties of the GaNAs alloy with advantages offered by the NW architecture. The presence of nitrogen in such NW structures was shown to be advantageous for improving their radiative efficiency as compared with N-free GaAs wires, likely due to suppression of surface recombination caused by N-assisted surface passivation.…”

Self-catalyzed core-shell GaAs/GaNAs nanowires grown on patterned Si (111) by gas-source molecular beam epitaxy

“…The self-catalyzed growth of GaAs/GaNAs nanowires on Si (111) has been pursued before by several groups. While fundamental studies [21][22][23] have advanced our understanding of the carrier dynamics in GaAs/GaNAs core/shell nanowires, the patterned growth of GaAs/GaNAs core/shell nanowires-important for device applications-has not been attempted. Further, detailed and high resolution transmission electron microscopy (HRTEM) studies to uncover the quality of the GaAs/Si and GaAs/GaNAs/Si interfaces are yet to be performed.…”