Phonon dispersion in strained heterovalent (Si)n/(GaAs)m (001) superlattices has been calculated using first-principles force constants. Raman scattering experiments have been conducted on fifteen-period (Si)2/(GaAs)28 and (Si)3/(GaAs)50 superlattices synthesized by molecular-beam epitaxy. In addition to folded acoustic modes, confined Si-like and quasiconfined GaAs-like optical modes appear in the superlattice spectra, in spite of the extremely small thickness of the Si layers. Quantitative agreement is found between measured and calculated phonon frequencies, confirming that a description in terms of strain- and confinement-induced shifts of the optical phonons is appropriate for these structures.
Phonons in Si/GaAs superlattices / G., Scamarcio; V., Spagnolo; Molinari, Elisa; L., Tapfer; Sorba, Lucia; G., Bratina; A., Franciosi. - In: PHYSICAL REVIEW. B, CONDENSED MATTER. - ISSN 0163-1829. - STAMPA. - 46:(1992), pp. 7296-7299. [10.1103/PhysRevB.46.7296]
Phonons in Si/GaAs superlattices
MOLINARI, Elisa;SORBA, Lucia;
1992
Abstract
Phonon dispersion in strained heterovalent (Si)n/(GaAs)m (001) superlattices has been calculated using first-principles force constants. Raman scattering experiments have been conducted on fifteen-period (Si)2/(GaAs)28 and (Si)3/(GaAs)50 superlattices synthesized by molecular-beam epitaxy. In addition to folded acoustic modes, confined Si-like and quasiconfined GaAs-like optical modes appear in the superlattice spectra, in spite of the extremely small thickness of the Si layers. Quantitative agreement is found between measured and calculated phonon frequencies, confirming that a description in terms of strain- and confinement-induced shifts of the optical phonons is appropriate for these structures.File | Dimensione | Formato | |
---|---|---|---|
PhysRevB.46.7296.pdf
Solo gestori archivio
Tipologia:
Versione pubblicata dall'editore
Dimensione
257.63 kB
Formato
Adobe PDF
|
257.63 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris