US-Turkey Cooperative Research: Search for Microscopic Theory for the State-of-the-Art Epitaxial Growth of Semiconductors

该奖项是为了支持加州大学戴维斯分校物理系方庆尧博士和土耳其安卡拉比尔肯特大学物理系Selim Ciraci博士之间的合作研究项目。两位科学家建议从最基本的角度来研究同外延生长和异质外延生长，以及特定表面活性剂在改变半导体表面上这些生长过程中所起的作用：表面上有一个，几个和一个单层附着原子。目标是发展一种微观的理解，为更好地控制生长过程提供基础。这两位科学家将使用一种能够区分具有小能量差异的构型的从头算方法，在小尺寸系统中研究衬底与进入的原子或表面活性剂之间的基本相互作用。相互作用的细节将用于开发经验势能函数，可以准确地描述各种低配位构型。这些函数将用于研究在外延生长过程中发生的各种原子过程。他们将分析模拟生长中每一个主要步骤的电子结构，以弥合真实空间中原子构型预测与扫描隧道显微镜（STM）实验结果之间的差距。范围：该项目将支持两个具有互补能力和机构设施的团队之间的协作。Drs。Fong和Ciraci已经在这一领域独立发表了论文，他们的专业知识的结合将有助于这项研究。加州大学戴维斯分校和比尔肯特大学的实验工作都有重要的能力。该项目将包括一名来自加州大学戴维斯分校的美国研究生前往比尔肯特参加那里的研究，以及两名来自比尔肯特的学生前往戴维斯在方博士的实验室工作。在这一共同努力中获得的知识将为电子和光电设备的设计和制造中的技术应用提供理论背景，这将使两国受益。该项目完全符合国际项目司的目标。

Description: This award is for support of a collaborative research project between Dr. Ching-Yao Fong, Physics Department at the University of California at Davis, and Dr. Selim Ciraci, Physics Department at Bilkent University in Ankara, Turkey. The two scientists propose to investigate both homo- and hetero-epitaxial growths and the role that specific surfactants play in modifying these growth processes on semiconductor surfaces from the most elementary point of view: with one, several and one monolayer adatoms on a surface. The objective is to develop a microscopic understanding that provides a foundation for better control of growth processes. The two scientists will study the basic interaction between the substrate and an incoming atom, or a surfactant, on small size system by using an ab-initio method that is capable of distinguishing between configurations that have small energy differences. The details of the interaction will be used to develop empirical potential energy functions that can accurately describe various low coordination configurations. These functions will be used to study various atomic processes that occur during epitaxial growth. They will analyze the electronic structure of every major step in simulated growth to bridge the gap between the predictions of atomic configurations in real space and the results of scanning tunneling microscopy (STM) experiments. Scope: This project will support collaboration between two teams with complementary capabilities and institutional facilities. Drs. Fong and Ciraci have independently published in this field, and the combination of their expertise would help this research. There are significant capabilities for the experimental work at both UC Davis and at Bilkent University. The project will involve travel of a US graduate student from UC Davis to Bilkent to participate in the research there, and travel by two students from Bilkent to Davis to work in Dr. Fong's laboratory. The knowledge gained in this joint effort will provide theoretical background for technological applications in the design and manufacture of electronic and opto-electronic devices that will benefit both countries. The project fits well within the objectives of the Division of International Programs.