法国科研中心光子与纳米结构实验室王肇中教授应我所集成技术中心主任杨富华研究员的邀请，将于8月28日上午来我所学术交流，并在“黄昆半导体科学技术论坛”上作第101期报告，望广大科研人员及研究生准时参加。

　　报告题目: Quantum impurity state and local electronic properties of semiconductor nanostructure

　　报告人: 王肇中教授(主任研究员，法国科研中心光子与纳米结构实验室)

　　报告时间: 2009年8月28日(星期五) 上午 10:00

　　报告地点: 中国科学院半导体研究所一号楼学术沙龙室

　　Abstract：Doping a semiconductor with foreign atoms allows to precisely control the concentration of charge carriers, a principle at the basis of virtually all electronic and optoelectronic devices. In quantum mechanics, an impurity inside a semi-conductor can be assimilated as a hydrogen atom. Binding energy and the Bohr radius of a single impurity are two essential parameters in this simple approximation. It has been highly desirable to measure the Bohr radius directly since last three decades.We use scanning tunneling microscopy and spectroscopy to study donor-like point defects which are located at the epitaxial surface of a quantum well (QW). Special designed InGaAs surface QWs are grown by molecular beam epitaxy (MBE) for this study. Four different QWs with thickness of 2, 6, 10 and 14 nm are investigated. By measuring the local density of the state in the QW with nanometer scale resolution, we are able to determine both the binding energy and the Bohr radius of single defects. In a QW of 14nm thickness, the binding energy of a single point defect is found to be 10 meV and its Bohr radius deduced is of 12nm. More, we find that the binding energy and the Bohr radius highly depend on the thickness of QW. The important increase of binding energy in semiconductor nanostructure might prohibit the impurity ionization process at room temperature for p-type doping. Our results are in quantitative agreement with the hydrogenic model. (PRL 100, 056806, 2008).In this talk, our investigation of the local electronic properties of semiconductor and their application in device are presented too.

　　报告人简介：王肇中教授，1985年获得法国格勒诺布尔大学博士学位，于1985年-1987年在美国普林斯顿大学物理系做博士后研究工作。他于1987年-1999年受聘于美国普林斯顿大学从事科研工作，曾担任副教授。王教授于1990年-2000年受聘于法国国家科研中心微结构和微电子实验室主任研究员，参与实验室管理，负责该实验室的基础研究项目，并参与制订法国国家纳米平台重建方案。自2000年至今，王教授担任法国科研中心光子与纳米结构实验室(LPN/CNRS)主任研究员。(系2000年至今法国五个国家纳米平台之一)。担任低温高真空隧道显微镜研究课题组组长。目前主要从事由分子束外延生长的III-V 族 (GaAs/GaAlAs, InGaAs,InP) 半导体超晶格结构，量子点，纳米线,和稀磁半导体(砷锰化镓)的电子结构和量子特性研究。同时，他也担任中国国家纳米科学中心首席科学家，并有多项国际学术兼职。他在国际学术刊物(SCI)共发表 108 篇论文。其中发表在 Nature,“物理快报”，“物理评论” 和“应用物理快报” (PRL，PR and APL) 的论文37篇，已发表的109 篇SCI论文共被引用 3300次, H 指数( Hirsch index:) 为29。