Crystal phase induced bandgap modifications in AlAs nanowires probed by resonant Raman spectroscopy.
ACS Nano
; 7(2): 1400-7, 2013 Feb 26.
Article
em En
| MEDLINE
| ID: mdl-23281738
ABSTRACT
We report on a major modification of the fundamental electronic band structure of AlAs when grown as a nanoscaled wurtzite crystal. Resonant Raman spectra of individual AlAs-GaAs core-shell nanowires display a resonance between 1.83 and 2.18 eV for the AlAs E1(TO) phonon mode. Our findings substantiate the lowest conduction band of wurtzite AlAs to comprise Γ8 symmetry and a low effective mass in agreement with calculations reported recently. The electronic resonance falls below the X, L, and Γ valleys known for AlAs in the zincblende phase. This result points toward a direct nature of wurtzite AlAs and is expected to apply more generally to semiconductors that in the bulk phase exhibit L valleys at lower energies than the conduction band at the Γ point.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
ACS Nano
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Alemanha