Project/Area Number |
22540332
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Condensed matter physics I
|
Research Institution | University of the Ryukyus |
Principal Investigator |
|
Co-Investigator(Kenkyū-buntansha) |
TAKEDA Sakura 奈良先端科学技術大学院大学, 物質創成科学研究科, 助教 (30314537)
柳澤 将 琉球大学, 理学部, 助教 (10403007)
|
Project Period (FY) |
2010-04-01 – 2014-03-31
|
Project Status |
Completed (Fiscal Year 2013)
|
Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2013: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2011: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2010: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
|
Keywords | Si, Ge / バンド / 異方性 / 歪み / 表面反転層 / 表面・界面物性 / 半導体物性 / サブバンド / Si,Ge |
Research Abstract |
Band anisotropy of Si and Ge and applied tensile or compressive strain with various orientations cooperate synergistically to change the band structure remarkably. As for the Si valence band, we have investigated the anisotropy of the bulk band or the surface subband induced by strain, and searched for those strain types which contribute to improve hole mobility. Furthermore, we have clarified the conspicuous effect of relative atom displacement of two atoms in the crystal unit cell (internal strain) on the band structure. We have found the direction of uniaxial tensility and the plane orientation of biaxial tensility which cause the indirect-direct band-gap transition of Ge, and evaluated the strain magnitude where the transition occurs. Observing the Si valence band by angle-resolved photoemission spectroscopy, we have found that biaxial tensility lifts up the band with a small in-plane hole effective mass to the valence top.
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