METHODOLOGY OF ABRUPT HETEROSTRUCTURES - BAND DIAGRAM CALCULATIONS

A methodology for calculating the energy band diagrams of abrupt heter ostructures using the band discontinuities and the interface charge de nsity as parameters is presented. The calculations are based on two ba sic equations which are universally accepted-the lineup of the bands r elative to the common Fermi level (which embodies the valence band dis continuity) and the charge neutrality (which embodies the interface ch arge density). The two equations, with the aid of Poisson's equation, yield the total band bending on each side of the interface and the dep endence of the energy bands on the position (i.e. the band diagram). T he methodology is illustrated for the HgTe-CdTe semimetal-semiconducto r heterostructure, and demonstrates the interplay of band offsets and interface charges in establishing the nature of a heterostructure (eit her rectifying or ohmic) and in determining the potential barrier heig ht, for both n-type and p-type CdTe. The methodology presented in this study is general and can be applied to additional semiconductor-semic onductor and semimetal-semiconductor heterostructures. Copyright (C) 1 996 Elsevier Science Ltd