BAND DIAGRAM OF A HGTE-CDTE SEMIMETAL-SEMICONDUCTOR ABRUPT HETEROSTRUCTURE

The energy-band diagram and interface potentials at a HgTe-CdTe abrupt heterostructure are presented. An analytic approximation is formulate d and compared to an exact (numeric) calculation of the interface pote ntials. The error introduced by the analytic approximation is negligib le for a wide range of doping levels of the CdTe. The analysis predict s that HgTe forms ohmic contacts to p-type CdTe and rectifying junctio ns to n-type CdTe. Interface charges above 10(12) cm-2 modify the inte rface potentials. Positive interface charge imposes depletion in p-typ e CdTe resulting in potential barriers that may degrade the ohmic prop erties of the contacts. The methodology presented in this study may be extended to additional semimetal-semiconductor heterostructures.