Open AccessBand structure of strained Si/(111)Si1-xGex: a first principles investigation
Author(s) -
Jianjun Song,
Heming Zhang,
Xianying Dai,
Huiyong Hu,
Xuan Rong-Xi
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.57.5918
Subject(s) - pseudopotential , materials science , effective mass (spring–mass system) , band gap , electronic band structure , condensed matter physics , valence band , conduction band , density functional theory , enhanced data rates for gsm evolution , first principle , electronic circuit , electron , semimetal , optoelectronics , physics , computer science , telecommunications , quantum mechanics
There has been a great interest in the strained Si CMOS technology lately, especially the modification of band structures which provides a theoretical basis for the design of the high-speed and high-performance devices and circuits. Calculations were performed on the band structures in strained Si/(111)Si1-xGex(0≤x≤0.4) by the first-principle pseudopotential approach of the plane wave based upon the density functional theory. It was found that the conduction band (CB) edge is characterized by the six valleys all the same, that valence band (VB) edge degeneracies are partially removed and that the electron mass in CB is unaltered under strain while the hole mass decreases along the 100 direction with increasing x. In addition, the fitted dependence of bandgap on x are in good agreement with KP theoretical calculation, from which the quantitative data supply valuable references to the devices design.