Virtual Synthesis of 3D Nanoheterostructure Units with Pre-Designed Charge Transport Properties

该项目将开发一种基本的、基于理论的计算纳米制造方法，用于虚拟合成三维(3D)纳米异质结构单元-尺寸小于10纳米的设备。实际上，这些结构是具有预先设计好的电子性质的“人造分子”。这些特性由制造过程的参数、基本构建块的结构和组成以及最终器件的结构和组成决定。在原子水平上操纵纳米系统特性的机会将允许虚拟制造超高密度、多功能的3D纳米集成电路和设备。该项目将(1)评估纳米级构建块的基本物理和化学约束，(2)开发一种统一的量子统计力学方法来研究纳米系统中的非平衡现象，以及(3)努力了解纳米构建块的结构、化学和组成与合成的3D纳米异质结构的电子性质之间的关系。基本的理论描述将被简化，以开发最简单的3D纳米异质结构的模拟模型，例如由孔中的纳米晶体组成的量子点，或者通过在孔周围制造纳米级的层而形成的量子点。这些模型将被用来制造具有预先设计的属性的虚拟原型，并将预测的性能与实验结果进行比较。纳米尺寸的器件(一纳米大约是氢原子直径的10倍)的属性既不同于块体材料的属性，也不同于单个原子的属性。为了计算诸如集成电路中的晶体管之类的宏观器件的电学性质，人们可以利用材料的整体性质。相反，要计算单个原子或分子的性质，就必须使用量子理论。然而，计算纳米设备的电子性质需要在这两个长度尺度之间架起桥梁，并处理可能数千或数百万个可能不同的原子，这些原子可能处于非平衡状态。要做到这一点，需要相当大的理论发展，随后需要开发适当的计算模型。该项目将致力于解决这一具有挑战性的中等规模的理论，并将其应用于对几个简单纳米级设备的虚拟制造进行建模。通过将模型结果与实验结果进行比较，对结果进行了检验。

This project will develop a fundamental, theory-based computational nanofabrication methodology for the virtual synthesis of three-dimensional (3D) nanoheterostructure units - devices with dimensions less than 10 nanometers. In effect, these structures are "artificial molecules" with pre-designed electronic properties. These properties are determined by the parameters of the fabrication process, the structure and composition of the fundamental building blocks, and the structure and composition of the final device. The opportunity to manipulate the properties of nanosystems at the atomic level will allow the virtual fabrication of super dense, multifunctional 3D nanoscale integrated circuits and devices. The project will (1) evaluate fundamental physical and chemical constraints on the nanoscale building blocks, (2) develop a unified quantum statistical mechanical approach to non-equilibrium phenomena in nanosystems, and (3) work to understand the relations between the structure, chemistry, and composition of the nanoscale building blocks and the electronic properties of the synthesized 3D nanoheterostructures. The fundamental theoretical descriptions will be simplified to develop simulation models for the simplest 3D nanoheterostructures, such as a quantum dot consisting of a nanoscale crystal in a pore or a quantum dot formed by fabricating nanoscale layers surrounding a pore. These models will be used to fabricate virtual prototypes with pre-designed properties, and the predicted performance will be compared with experimental results.The properties of devices with nanometer dimensions (a nanometer is approximately 10 times the diameter of a hydrogen atom) differ from both the properties of bulk materials and those of individual atoms. To calculate the electronic properties of a macroscopic device such as a transistor in an integrated circuit one can make use of the bulk properties of materials. Conversely, to calculate the properties of a single atom or molecule it is necessary to use quantum theory. However, a calculation of the electronic properties of a nanoscale device requires bridging between these two length scales and dealing with perhaps thousands or millions of potentially different individual atoms, potentially in non-equilibrium states. To accomplish this requires a considerable development of theory and subsequently the development of appropriate computational models. This project will endeavor to address this challenging intermediate scale of theory and apply it to modeling the virtual fabrication of a few simple nanoscale devices. The results will be checked by comparing the model results with experimental work.