A detailed experimental investigation of the phonon-assisted emission in a high-quality c-plane GaN epilayer is presented up to 200 K. By performing photoluminescence and reflectivity measurements, we find important etaloning effects in the phonon-replica spectra, which have to be corrected before addressing the lineshape analysis. Direct experimental evidence for free exciton thermalization is found for the whole temperature range investigated. A close comparison with existing models for phonon replicas originating from a thermalized free exciton distribution shows that the simplified and commonly adopted description of the exciton-phonon interaction with a single excitonic band leads to a large discrepancy with experimental data. Only the consideration of the complex nature of the excitonic band in GaN, including A and B exciton contributions, allows accounting for the temperature dependence of the peak energy, intensity, and lineshape of the phonon replicas.

Probing exciton density of states through phonon-assisted emission in GaN epilayers: A and B exciton contributions / Lucia Cavigli; Riccardo Gabrieli; Massimo Gurioli; Franco Bogani; Eric Feltin; Jean-François Carlin; Raphaël Butté; Nicolas Grandjean; Anna Vinattieri. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 82:(2010), pp. 115208-1-115208-7. [10.1103/PhysRevB.82.115208]

Probing exciton density of states through phonon-assisted emission in GaN epilayers: A and B exciton contributions

CAVIGLI, LUCIA;GABRIELI, RICCARDO;GURIOLI, MASSIMO;BOGANI, FRANCO;VINATTIERI, ANNA
2010

Abstract

A detailed experimental investigation of the phonon-assisted emission in a high-quality c-plane GaN epilayer is presented up to 200 K. By performing photoluminescence and reflectivity measurements, we find important etaloning effects in the phonon-replica spectra, which have to be corrected before addressing the lineshape analysis. Direct experimental evidence for free exciton thermalization is found for the whole temperature range investigated. A close comparison with existing models for phonon replicas originating from a thermalized free exciton distribution shows that the simplified and commonly adopted description of the exciton-phonon interaction with a single excitonic band leads to a large discrepancy with experimental data. Only the consideration of the complex nature of the excitonic band in GaN, including A and B exciton contributions, allows accounting for the temperature dependence of the peak energy, intensity, and lineshape of the phonon replicas.
82
115208-1
115208-7
Lucia Cavigli; Riccardo Gabrieli; Massimo Gurioli; Franco Bogani; Eric Feltin; Jean-François Carlin; Raphaël Butté; Nicolas Grandjean; Anna Vinattieri
File in questo prodotto:
File Dimensione Formato  
PRB_GaN.pdf

Accesso chiuso

Tipologia: Versione finale referata (Postprint, Accepted manuscript)
Licenza: DRM non definito
Dimensione 660.35 kB
Formato Adobe PDF
660.35 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in FLORE 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: http://hdl.handle.net/2158/392853
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 6
  • ???jsp.display-item.citation.isi??? 6
social impact