A New Tight Binding Theory of Band Offset at Semiconductor Heterojunction

Valence banc! offset is a measure of the difference in the valence band
edp of the constituents of a heterojunction such as GaAsIG-e. In a tight binding
approach, the bani offset involves the valence hand maxima and hybrid energy;
and previously, these have been calculated from first principles Hartree-%ck
mcrhod. In this thesis a new tight binding approach is formulated in terms of
quantum d.efects so that band offset could be calculated from the measured atomic
spectroscopic term values and predicted for a number of novel heterojunctions. As a result, the calculated band offset is found to be in reasonable agreement with experiment for a number of existing heterojunctions, like InAs/AlSb, InSb/Sn, AIAs/GcaAs, InAs/GaSb, GaAs/InAs and Gi As/Ge