  A closed-form model is developed to evaluate the band-edge shift caused by
quantum confinement for a two-dimensional non-parabolic carrier-pocket. Based
on this model, the symmetries and the band-shifts of different carrier-pockets
are evaluated for BiSb thin films that are grown along different crystalline
axes. The phase diagrams for the BiSb thin film systems with different growth
orientations are calculated and analyzed.
