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It was observed that the conduction-band minimum of
InAs is lower in energy than the valence-band maximum
of GaSb and causing the nonrectification on characteristic.
Such unusual nonrectifying p-n junction is the direct
consequence of interpenetration between the GaSb valence band
andthe InAs conduction band. Since the InAs-GaSb
superlattices can have aband gap smaller than that of either
constituent material. InAs-GaSb superlattices have the
modifiable band gap,but the absorption coefficient shall
decrease rapidly when the period thickness is over 100o (d1=
d2). So it has a good response in 3-5 um, worse in 8-12um.
The new proposal offered a normal incidence valence
intersubband optical transition at 10um. So it is potential to
fabricate the long wavelength devices. In this thesis, the
InAs-GaSb superlattices were deposited by MOCVD. The quality
and period thickness are determined by x-ray double crystal
rocking curves. The absorption spectra were obtained by
FTIR. We alsouse the LCAO model and transform matrix to
calculate the band structure and transition energy of InAs-
GaSb superlattice. These results are not worse than the
other laboratory pressented.
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