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Determination of the Optimal Shell Thickness for Self-Catalyzed GaAs/AlGaAs Core–Shell Nanowires on Silicon
- Source :
- Nano Letters, Nano Letters, 2016, 16 (6), pp.3426-3433. ⟨10.1021/acs.nanolett.5b03917⟩, Nano Letters, American Chemical Society, 2016, 16 (6), pp.3426-3433. ⟨10.1021/acs.nanolett.5b03917⟩
- Publication Year :
- 2016
- Publisher :
- American Chemical Society (ACS), 2016.
-
Abstract
- International audience; We present a set of experimental results showing a combination of various effects, that is, surface recombination velocity, surface charge traps, strain, and structural defects, that govern the carrier dynamics of self-catalyzed GaAs/AlGaAs core-shell nano wires (NWs) grown on a Si(111) substrate by molecular beam epitaxy. Time-resolved photoluminescence of NW ensemble and spatially resolved cathodoluminescence of single NWs reveal that emission intensity, decay time, and carrier diffusion length of the GaAs NW core strongly depend on the AlGaAs shell thickness but in a nonmonotonic fashion. Although 7 nm AlGaAs shell can efficiently suppress the surface recombination velocity of the GaAs NW core, the influence of the surface charge traps and the strain between the core and the shell that redshift the luminescence of the GaAs NW core remain observable in the whole range of the shell thickness. In addition, the band bending effect induced by the surface charge traps can alter the scattering of the excess carriers inside the GaAs NW core at the core/shell interface. If the AlGaAs shell thickness is larger than SO nm, the luminescence efficiency of the GaAs NW cores deteriorates, ascribed to defect formation inside the AIGaAs shell evidenced by transmission electron microscopy.
- Subjects :
- Luminescence
Photoluminescence
Materials science
Nanowire
Shell (structure)
Core-shell wnanowires
Bioengineering
Nanotechnology
Cathodoluminescence
III-As semiconductors
02 engineering and technology
Substrate (electronics)
01 natural sciences
Molecular physics
Passivation
Condensed Matter::Materials Science
0103 physical sciences
General Materials Science
Surface charge
Recombination Velocity
[PHYS]Physics [physics]
010302 applied physics
Mechanical Engineering
Surface Charges
General Chemistry
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
021001 nanoscience & nanotechnology
Condensed Matter Physics
GaAs Nanowires
Band bending
Molecular-Beam Epitaxy
0210 nano-technology
Molecular beam epitaxy
Subjects
Details
- ISSN :
- 15306992 and 15306984
- Volume :
- 16
- Database :
- OpenAIRE
- Journal :
- Nano Letters
- Accession number :
- edsair.doi.dedup.....b909b31028b8ca118705fecdfdb4e508