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

Western Kentucky University Research Foundation, Bowling Green KY

Investigators

Abstract

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.