ELECTRONIC BAND STRUCTURE OF BISMUTH TELLURIDE

The electronic band structure of Bi2Te3 has been calculated by using the pseudopotential method. A detailed analysis of the sensitivity of the various levels indicated the impossibility of using some analytic form of the effective potential. The Fourier coefficients of the pseudopotential have been therefore chosen semi-empirically so as to obtain an energy gap throughout the whole Brillouin zone without any band overlap. The spin-orbit splitting of the bands has been evaluated by using an approach based on the tight binding method, so as to reduce the crystal spin-orbit splitting to a linear combination of atomic splittings. The resulting band scheme, when related to the experimental data, permits us to give a reasonable interpretation of the optical spectrum and of the galvanomagnetic properties of the crystal. © 1968 Società Italiana di Fisica.