SGER: Exploration of Ordering Mechanisms in the Nucleationless Self-Assembly of Quantum Dot Islands

这个SGER项目将探索一种独特的方法来创建自组装的远程有序阵列，三维（3D）量子点岛。这个项目正在探索的概念是，通过无核孤岛，均匀大小的量子点岛屿的周期性阵列可以在适当的条件下自发形成，或者可以由“弱侵入性”生长调节剂诱导，从而促进和增强现有的有序力。该研究将使用超高真空系统中的生长和生长后的原位扫描隧道显微镜来探索QD岛屿形成的各个方面。Si（100）上的外延SiGe合金将作为一个模型系统。将寻求一系列生长参数，在这些参数中岛屿形成而不形成三维核。将研究异质外延早期（具有离散面的岛形成之前）的表面形态演变，以检测QD岛自发自组织成周期阵列的可能驱动力。此外，基板表面的瞬态应变的光学干涉图案作为一种方式，加强这些驱动力，以施加远程秩序将被探索。该项目将探索一种新的创新方法来创建自组装的远程有序阵列，三维（3D）量子点岛。正在探索的想法涉及无核岛，即均匀大小的量子点岛的周期性阵列可以在适当的条件下自发形成。该项目为测试这些想法的初步研究设定了具体的目标和方法，并且几个关键问题可以由该项目适当地处理和解决

This SGER project will explore a unique approach to creating long-range ordered arrays of self-assembled, three-dimensional (3D) quantum dot islands. The concept being explored in this project is that with nucleation-less islanding, periodic arrays of uniformly sized QD islands may form spontaneously under suitable conditions-or may be induced by 'weakly invasive' growth modifiers that promote and enhance existing ordering forces. The research will use growth in an ultrahigh-vacuum system and post-growth, in-situ scanning tunneling microscopy to explore aspects of QD island formation. Epitaxial SiGe alloys on Si(100) will serve as a model system. A range of growth parameters in which islands form without 3D nucleation will be sought. The surface morphology evolution at early stages of heteroepitaxy (before islands with discrete facets form) will be studied to detect possible driving forces for spontaneous self-organization of QD islands into periodic arrays. Additionally, transient straining of the substrate surface by an optical interference pattern as a way of enhancing these driving forces to impose long-range order will be explored. %%% This project will explore a new and innovative approach to creating long-range ordered arrays of self-assembled, three-dimensional (3D) quantum dot islands. The idea being explored involves nucleation-less islanding, whereby periodic arrays of uniformly sized QD islands may form spontaneously under suitable conditions. The project sets specific goals and methods for an initial study to test these ideas, and several key issues can be appropriately addressed and resolved by the project.***