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 formulated and compared to an exact (numeric) calculation of the interface potentials. The error introduced by the analytic approximation is negligible for a wide range of doping levels of the CdTe. The analysis predicts that HgTe forms ohmic contacts to p-type CdTe and rectifying junctions to n-type CdTe. Interface charges above 10(12) cm-2 modify the interface potentials. Positive interface charge imposes depletion in p-type CdTe resulting in potential barriers that may degrade the ohmic properties of the contacts. The methodology presented in this study may be extended to additional semimetal-semiconductor heterostructures.