ENERGY-SPECTRUM OF RHOMBOHEDRAL III-V-VI2 COMPOUNDS - TERNARY ISOELECTRONIC ANALOGS OF BISMUTH-TYPE SEMIMETALS

A model of the electronic energy spectrum for the rhombohedral III-V-VI2 compounds (the ternary isoelectronic analogues of the bismuth-type semimetals and the IV-VI semiconductors) has been elaborated on the basis of the genesis of their crystalline structure from the simple cubic lattice as well as the derivation of the band spectrum from the atomic p states. Rhombohedral III-V-VI2 compounds are shown to be narrow-gap semiconductors, with two conduction and two valence bands located at Gamma - and L points of the Brillouin zone. The band structure of TlBiC2 VI compounds has been found to be normal, while that of TlSbC 2VI is inverted.