Self-Organization Mechanism and Electronic Properties of Semiconductor Quantum Dots

半导体量子点的自组织机制和电子特性

• 批准号: 13650333
• 负责人: OKADA Yoshitaka
• 金额: $ 2.18万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650333/
• 关键词: 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

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

利用导电扫描探针显微镜（SPM）技术研究了GaAs（311）B衬底上生长的InGaAs量子点的电学性质和自组织机制。量子点的制备采用原子氢辅助分子束外延技术，硅SPM针尖表面涂有Au，保证了其导电性，并同时测量了量子点表面的形貌和电流图像。导电SPM测量在真空中在室温下和在降低的温度下进行。利用这种技术，可以通过使用相同的导电AFM针尖来研究不同尺寸的量子点中的单电子隧穿事件，以及量子点表面上的任何其他任意位置。发现（1）QD的中心比其外围导电，以及（2）表面。是高电阻的。电导的差异是由于与表面状态相关的表面弯曲的局部修改。此外，我们发现在低温下，组装有序的量子点上的电导在空间上变得均匀，这可以通过这些应变量子点的横向耦合来解释

项目成果

R.Oshima, Y.Okada: "Growth of self-assembled GaInNAs quantum dots by atomic-H assisted RF molecular beam epitaxy"Thin Solid Films. (印刷中).

R.Oshima、Y.Okada：“通过原子 H 辅助射频分子束外延生长自组装 GaInNAs 量子点”固体薄膜（正在出版）。

R.Oshima, A.Ohmae, Y.Okada: "Fabrication of self-organized GaInNAs quantum dots by atomic-H assisted RF-molecular beam epitaxy"Journal of Crystal Growth. 281. 11-15 (2004)

R.Oshima、A.Ohmae、Y.Okada：“通过原子 H 辅助射频分子束外延制备自组织 GaInNAs 量子点”晶体生长杂志。

Y.Shimizu, Y.Okada: "Growth of high-quality GaAs/Si films for use in solar cell applications"Journal of Crystal Growth. 印刷中. (2004)

Y.Shimizu、Y.Okada：“用于太阳能电池应用的高质量 GaAs/Si 薄膜的生长”《晶体生长杂志》（2004 年）。

Y.Okada 他3名: "Control of dark currents in multi-quantum well solar cells fabricated by atomic H-assisted molecular beam epitaxy"Journal of Crystal Growth. 237-239. 1515-1518 (2002)

Y. Okada 和其他 3 人：“原子 H 辅助分子束外延制造的多量子阱太阳能电池中的暗电流控制”《晶体生长杂志》237-239 (2002)。

R.Oshima, N.Kurihara, H.Shigekawa, Y.Okada: "Electronic states of self-organized InGaAs quantum dots on GaAs (311)B studied by conductive probe microscope"Physica E. (in press). (2004)

R.Oshima、N.Kurihara、H.Shigekawa、Y.Okada：“通过导电探针显微镜研究 GaAs (311)B 上自组织 InGaAs 量子点的电子态”Physica E.（出版中）。