ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Photoluminescence for (AlAs)n(GaAs)n (n=1, 2, 3, and 4) ultrashort-period superlattices grown by flow-rate modulation epitaxy is analyzed at various temperatures between 4.6 and 300 K. An excitonic intense emission line caused by an indirect transition is observed at low temperatures. Another emission band, caused by a direct transition, appears at elevated temperatures. The results of photoluminescence excitation spectroscopy reveal that the superlattices have an indirect minimum band gap. The direct and indirect band-gap energies of these superlattices, with periods of up to 1 monolayer, are presented. A simple Kronig–Penney calculation shows relatively good agreement with the experimental results for direct transitions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.345123
