| Summary: | 碩士 === 國立中山大學 === 物理研究所 === 84 === We have developed a six-band k．p finite difference method
(KPFD) to calculate the electronic band structures of InAs-GaSb
super- lattices and AlSb-GaSb-InAs-GaSb-AlSb quantum wells. The
simple theoretical method combines the virtues of the envelope-
function (k．p) and bond-orbital model. All interaction
parameters involved are directly related to parameters for
describing bulk bands near the zone center in the bond-orbital
model or k．p model. The method can reproduce fairly accurate
bulk band structure near the center of the two-dimensional
Brillouin zone when we properly choose the interaction
parameters and the dis- tance between two adjacent pseudo-
layers. For intrinsic InAs-GaSb superlattices, we don't find
truly semimetallic band structure. At low temperature(∼4.2k),
the critical InAs thickness for a zero-gap semiconductor result
is approximately 120 A. The evolution of the InAs-GaSb band
structure with increasing periodicity is calculated and found
to be in excellent agreement with previous NBO (nearest
neighbor bond-orbital model) results. In AlSb-GaSb-InAs-GaSb-
AlSb quantum wells, we shall demonstrate that the semiconductor-
semimetal transition does exist in this hole-electron-hole
quantum wells systems.
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