| Project/Area Number |
13650333
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | University of Tsukuba |
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Principal Investigator |
OKADA Yoshitaka University of Tsukuba, Institute of Applied Physics, Associate Professor, 物理工学系, 助教授 (40224034)
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| Co-Investigator(Kenkyū-buntansha) |
川辺 光央 筑波大学, 物理工学系, 教授 (80029446)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2001: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Quantum dots / Self-organized growth / Self-organized quantum dots / Scanning probe microscopy / Conductive probe / Single-electron tunneling / 自己組織化成長技術 / 導電性プローブ / 自己組織化成長 / 人工原子 / 自己組織化ドット / 自己組織化結晶成長 / ドット間結合 |
|---|
| Research Abstract |
The conductive scanning probe microscope (SPM) technique was used in order to study the electronic properties and self-organization mechanism of InGaAs quantum dots (QDs) grown on GaAs (311)B substrates. The QDs were fabricated by atomic H-assisted molecular beam epitaxy, and Si SPM tips coated with Au, which warrants electrical conductivity were used to measure both the topographic and current images of QDs surface simultaneously. The conductive SPM measurements were performed in vacuum at room temperature and at lowered temperatures. With this technique, the single-electron tunneling events in the QDs of varying sizes, and of any other arbitrary positions on the QDs surface can be studied by using the same conductive AFM tip. It was found that (1) the center of a QD is more conductive than its periphery, and (2) the surface. in between the QDs is highly resistive. The differences in the conductance were due to the local modification of surface bending associated with the surface states. Further, it was found that the conductance becomes spatially uniform at all points over the packed and ordered QDs at low temperatures, which could be explained by lateral coupling of these strained QDs
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