Empirical Pseudopotential and Full-Brillouin-Zone k • p Electronic Structure of CdTe, HgTe, and Hg1-xCdxTe

Two alternative approximations of the electronic structure of CdTe and HgTe are proposed, both suited to the needs of accuracy and numerical efficiency of full-band carrier transport simulation: a local empirical pseudopotential (EPM) parametrization including relativistic corrections, and an original full-Brillouin-zone (FBZ) k center dot p model using two expansion points (Gamma and W). The EPM and k center dot p band structures closely match the available experimental and ab initio information, complemented with the results of new density functional theory (DFT)-local density approximation (LDA) calculations, for the conduction and valence bands relevant in transport phenomena. The EPM description of the binary compounds, featuring transferable Te pseudopotentials, is the basis for a computation of the electronic structure of the ternary alloy Hg1-xCdxTe in the framework of disorder-corrected virtual crystal approximation. The composition dependence of energy gaps, effective masses, and high-frequency dielectric constants are discussed and compared with available experimental data, and the novel FBZ approach is applied to the case of x = 0.7.