1. Built-in elastic strain and localization effects on GaAs luminescence of MOVPE-grown GaAs-AlGaAs core-shell nanowires
- Author
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Nicola Lovergine, Ilio Miccoli, Paola Prete, and Fabio Marzo
- Subjects
Materials science ,Photoluminescence ,Passivation ,business.industry ,Band gap ,Nanowire ,Condensed Matter Physics ,Optoelectronics ,General Materials Science ,Metalorganic vapour phase epitaxy ,Luminescence ,business ,Surface states ,Molecular beam epitaxy - Abstract
cm/s) surface carrier recombination ve-locity of GaAs and the nanowire large surface-to-volume ratios, effective and long-term stable passivation of GaAs surface states is however, necessary. A common approach is to overgrow a wider bandgap AlGaAs shell around GaAs nanowires. GaAs–AlGaAs core–shell nanowires thus show strong enhancement of luminescence intensity, improved minority carrier diffusion lenghts, and recombi-nation lifetimes with respect to bare GaAs nanowires [3, 4]. Also, the small lattice mismatch between the two materials may induce elastic strain fields and piezo-electric effects along the nanowire [111] axial direction; recently, Hocevar et al. [4] demonstrated the occurrence of systematic red-shifts in the core luminescence of molecular beam epitaxy (MBE) grown GaAs–Al
- Published
- 2013