Theory for n-surface charge layers in Hg1-xCdxTe MIS structures

The energy gap of the Hg1-xCdxTe-system can be controlled by the mole fraction x of Cd. This offers the possibility to use this material as a model system for systematic investigation especially in the narrow-gap region (corresponding to 0.16 ≤ x ≤ 0.25). The electronic structure, subband occupations, subband energies, and cyclotron masses are calculated for the two-dimensional electron gas in MIS structures with this material using an approximate self-consistent method. Both, inversion and accumulation conditions are considered. Comparisons with existing limited theoretical results and with experimental ones a) show the accuracy of the method used and b) allow to interpret the detailed experimental results from Shubnikov-de Haas and cyclotron measurements available now. Predictions are made on the composition dependence of the electronic structure especially for inversion conditions. (author)