Narrow-gap semiconducting silicides: the band structure

Electronic property simulation of the narrow-gap semiconducting rhenium and ruthenium silicides has been performed by the linear muffin-tin orbital method (LMTO) within the local density approximation. ReSi1.75 was found to have an indirect gap value of 0.16 eV. The first direct transition with appreciable oscillator strength at 0.30 eV is predicted. Ru2Si3 is revealed to be a direct gap semiconductor with an energy gap of 0.41 eV, while the isostructural Ru2Ge3 has a competitive indirect-direct character of the band gap of about 0.31 eV. (C) 2000 Elsevier Science B.V. All rights reserved.