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Effects of the surface preparation and buffer layer on the morphology, electronic and optical properties of the GaN nanowires on Si
- Source :
- Nanotechnology. 30(39)
- Publication Year :
- 2019
-
Abstract
- The role of Si (111) substrate surface preparation and buffer layer composition in the growth, electronic and optical properties of the GaN nanowires (NWs) synthesized via plasma-assisted molecular beam epitaxy is studied. A comparison study of GaN NWs growth on the bare Si (111) substrate, silicon nitride interlayer, predeposited AlN and GaO x buffer layers, monolayer thick Ga wetting layer and GaN seeding layer prepared by the droplet epitaxy is performed. It is demonstrated that the homogeneity and the morphology of the NW arrays drastically depend on the chosen buffer layer and surface preparation technique. An effect of the buffer and seeding layers on the nucleation and desorption is also discussed. The lowest NWs surface density of 14 μm-2 is obtained on AlN buffer layer and the highest density exceeding the latter value by more than an order of magnitude corresponds to the growth on the 0.3 ML thick Ga wetting layer. It is shown, that the highest NWs mean elongation rate is obtained with AlN buffer layer, while the lowest elongation rate corresponds to the bare Si (111) surface and it is twice as lower as the first case. It is found, that use of AlN buffer layer corresponds to the most homogeneous NWs array with the smallest length dispersion while the least homogeneous array corresponds to the bare Si substrate. Vertically aligned GaN NWs array on the wide bandgap GaO x semiconductor buffer layer grown by plasma-enhanced chemical vapor deposition demonstrates its potential for electronic applications. Photoluminescence (PL) study of the synthesized samples is characterized by an intense optical response related to the excitons bound to neutral donors. The highest PL intensity is obtained in the sample with AlN buffer layer.
- Subjects :
- Materials science
Silicon
chemistry.chemical_element
Bioengineering
02 engineering and technology
Chemical vapor deposition
010402 general chemistry
Epitaxy
01 natural sciences
chemistry.chemical_compound
Monolayer
General Materials Science
Electrical and Electronic Engineering
Wetting layer
business.industry
Mechanical Engineering
General Chemistry
021001 nanoscience & nanotechnology
0104 chemical sciences
Surface coating
chemistry
Silicon nitride
Mechanics of Materials
Optoelectronics
0210 nano-technology
business
Molecular beam epitaxy
Subjects
Details
- ISSN :
- 13616528
- Volume :
- 30
- Issue :
- 39
- Database :
- OpenAIRE
- Journal :
- Nanotechnology
- Accession number :
- edsair.doi.dedup.....b0550f6450e23cb6b1d79444ca636380