Characterization of molecular‐beam epitaxially grown HgTe films by Shubnikov–de Haas measurements

Abstract

The oscillatory magnetoresistance (the Shubnikov–de Haas effect) has been used to investigate both three‐ and two‐dimensional electronic properties of films (∼2 μm thick) of HgTe grown by molecular‐beam epitaxial methods. Two‐dimensional behavior is found to arise from electrons constrained in an accumulation layer near the CdTe–HgTe interface on samples grown on (112) oriented CdTe substrates. Electron densities and effective masses of three electric subbands in two samples with different total densities are determined. The masses of lower subbands are higher, their values decreasing with decreasing total electron density and converging to the bulk value at low densities. This agrees with predictions of a triangular potential‐well model and a pronounced band nonparabolicity. Lower subbands are characterized by higher Dingle temperatures.