First-principles calculations of electronic structure and optical properties of strained Mg2Si

• Published in: Chinese science bulletin Vol. 55; no. 21; pp. 2236 - 2242
• Main Authors: Chen, Qian, Xie, Quan, Zhao, FengJuan, Cui, DongMeng, Li, XuZhen
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science China Press 01.07.2010
• Subjects: Chemistry/Food Science; Deformation; Dielectric constant; Earth Sciences; Engineering; Humanities and Social Sciences; Intermetallics; Lattices; Life Sciences; Magnesium; Magnesium compounds; Mg2Si; multidisciplinary; Physics; Science; Science (multidisciplinary); Semiconductors; Silicides; 光学性质; 各向同性; 晶格变形; 电子结构; 第一原理赝势法; 静态介电常数; strain; magnesium silicide; first-principles; band structure; dielectric function
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1007/s11434-010-3280-7

A detailed theoretical study on structural, electronic and optical properties of Mg2Si under the isotropic lattice deformation was performed based on the first-principles pseudopotential method. The results show that the isotropic lattice deformation results in a linear decrease in the energy gap for the direct Г15-Г1 and indirect Г15-L1 transitions from 93% to 113%, while the indirect band gap Г15-X1 increases from 93% to 104% and then reduces over 104%. When the crystal lattice is 93% compressed and 113% stretched, the magnesium silicide is a zero-gap semiconductor. Furthermore, the isotropic lattice deformation makes the dielectric function shift and the static dielectric constant change.