Calculation of the Electronic Structure and Energy Broadening of SixGe1-x Alloys

• Published in: Physica status solidi. B. Basic research Vol. 223; no. 3; pp. 793 - 797
• Main Authors: Vinga, E.S., Theodorou, G.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag Berlin GmbH 01.02.2001; WILEY‐VCH Verlag Berlin GmbH; Wiley
• Subjects: 71.15.Ap; 71.20.Nr; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron density of states and band structure of crystalline solids; Electron states; Elemental semiconductors; Exact sciences and technology; Physics; Band structure; Valence bands; Inorganic compounds; Semiconductor materials; Ge-Si alloys; Theoretical study; Binary compounds; Composition effect; Energy-level transitions; Electronic structure; Tight binding approximation; Band offset; Recursion method
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/1521-3951(200102)223:3<793::AID-PSSB793>3.0.CO;2-0

The Haydock recursion method is used to study the electronic structure of the SixGe1—x alloy. The direct energy band gap of this material as a function of silicon concentration is calculated at the critical symmetry points Γ, X and L. A systematic theoretical study of the alloy's energy broadening, produced by disorder, at the same symmetry points is also presented. It was found that the broadening is significant mainly for the conduction band, while for the valence band it is negligible. The theoretical results are in satisfactory agreement with the reported experimental ones for the entire concentration range.