Self-Assembled formation of long, thin, and uncoalesced GaN nanowires on crystalline TiN films
| Autor: | Sergio Fernández-Garrido, Oliver Brandt, Vladimir M. Kaganer, David van Treeck, Lutz Geelhaar, Gabriele Calabrese, Jelle J. W. Goertz |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Nanowire Nucleation FOS: Physical sciences chemistry.chemical_element Physics::Optics Crystal growth Applied Physics (physics.app-ph) 02 engineering and technology Epitaxy 01 natural sciences Condensed Matter::Materials Science 0103 physical sciences General Materials Science Electrical and Electronic Engineering Thin film 010302 applied physics Coalescence (physics) Surface diffusion Condensed Matter - Materials Science business.industry Materials Science (cond-mat.mtrl-sci) Physics - Applied Physics 021001 nanoscience & nanotechnology Condensed Matter Physics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Atomic and Molecular Physics and Optics chemistry Optoelectronics 0210 nano-technology business Tin |
| Popis: | We investigate in detail the self-assembled nucleation and growth of GaN nanowires by molecular beam epitaxy on crystalline TiN films. We demonstrate that this type of substrate allows the growth of long and thin GaN nanowires that do not suffer from coalescence, which is in contrast to the growth on Si and other substrates. Only beyond a certain nanowire length that depends on the nanowire number density and exceeds here 1.5 {\mu}m, coalescence takes place by bundling, i.e. the same process as on Si. By analyzing the nearest neighbor distance distribution, we identify diffusion-induced repulsion of neighboring nanowires as the main mechanism limiting the nanowire number density during nucleation on TiN. Since on Si the final number density is determined by shadowing of the impinging molecular beams by existing nanowires, it is the difference in adatom surface diffusion that enables on TiN the formation of nanowire ensembles with reduced number density. These nanowire ensembles combine properties that make them a promising basis for the growth of core-shell heterostructures. Comment: The final publication is available at link.springer.com |
| Databáze: | OpenAIRE |
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