Electronic structure of Si/Ge semiconductor superlattices
Author
Gülseren, Oğuz
Advisor
Çıracı, Salim
Date
1988Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
A brief review about the two dimensional electron systems and especially
band offsets is given. The electronic properties of the Si„/Ge„(001) strained
superlattices as a function of the superlattice periodicity and the band misfit
is investigated by using the empirical tight-binding method. The difference
between the direct and indirect band gaps is reduced from 2.01 eV for bulk
Si to 0.01 eV for n = 6. Consequently, the superlattice with n = 6 can be
considered as quasi-direct, while it is at least 0.15 eV for n = 4 case. For the
cases n=5,6, and 8, the band gap might become direct for large values of band
misfit.
Keywords
superlatticesband discontinuity
band line-up
band offset
strained superlattices
optical transition