The core photoluminescence emission of MOVPE-grown GaAs-Al0.33Ga0.67As core-shell nanowires is studied as function of the relevant geometrical parameter of these nanostructures, namely the shell-thickness to core-radius ratio hs/Rc. 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 hs/Rc < 1, the intrinsic strain-free excitonic emission being identified at 1.510 eV, and further ascribed to bound heavy-hole excitons. For hs/Rc > 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-Al0.33Ga0.67As core-shell nanowires as function of their shell-thickness to core-radius ratio hs/Rc.

Built-in elastic strain and localization effects on GaAs luminescence of MOVPE-grown GaAs-AlGaAs core-shell nanowires

PRETE, Paola;MICCOLI, ILIO;MARZO, Fabio;LOVERGINE, Nicola
2013-01-01

Abstract

The core photoluminescence emission of MOVPE-grown GaAs-Al0.33Ga0.67As core-shell nanowires is studied as function of the relevant geometrical parameter of these nanostructures, namely the shell-thickness to core-radius ratio hs/Rc. 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 hs/Rc < 1, the intrinsic strain-free excitonic emission being identified at 1.510 eV, and further ascribed to bound heavy-hole excitons. For hs/Rc > 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-Al0.33Ga0.67As core-shell nanowires as function of their shell-thickness to core-radius ratio hs/Rc.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11587/389498
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 7
social impact