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Built‐in elastic strain and localization effects on GaAs luminescence of MOVPE‐grown GaAs–AlGaAs core–shell nanowires
Author(s) -
Prete Paola,
Miccoli Ilio,
Marzo Fabio,
Lovergine Nico
Publication year - 2013
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201308046
Subject(s) - nanowire , exciton , photoluminescence , shell (structure) , metalorganic vapour phase epitaxy , radius , core (optical fiber) , luminescence , binding energy , condensed matter physics , materials science , redshift , molecular physics , atomic physics , nanotechnology , physics , optoelectronics , composite material , epitaxy , computer security , layer (electronics) , quantum mechanics , galaxy , computer science
The core photoluminescence emission of MOVPE‐grown GaAs–Al 0.33 Ga 0.67 As core–shell nanowires is studied as function of the relevant geometrical parameter of these nanostructures, namely the shell‐thickness to core‐radius ratio h s / R c . The energy of the dominant emission peak was compared with values of the GaAs heavy‐ and light‐hole excitons redshifted by a uniaxial tensile strain, the latter calculated assuming perfect coherence at the core/shell interface and elastic energy equilibrium within the nanowires. Good agreement is obtained for h s / R c < 1, the intrinsic strain‐free excitonic emission being identified at 1.510 eV, and further ascribed to bound heavy‐hole excitons. For h s / R c > 1 increasingly larger redshifts (up to ∼9 meV in excess of values calculated based on our elastic strain model) are observed, and tentatively ascribed to shell‐dependent exciton localization effects.Experimental and calculated bound exciton peak energies for GaAs–Al 0.33 Ga 0.67 As core–shell nanowires as function of their shell‐thickness to core‐radius ratio h s / R c . (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)