Materials World Network: Understanding and Controlling Optical Excitations in Individual Hybrid Nanostructures

University Of Arkansas, Fayetteville AR

Investigators

Abstract

This Materials World Network project focuses on exploring the fundamental mechanisms governing the optical excitations of two specific hybrid material systems of common interest, namely (1) quantum-dot/quantum-well coupled via tunneling and (2) metal/semiconductor coupled via their exciton-plasmon resonance. The goal is to establish the relationships between structure and function in these systems that will create new knowledge with impact on plasmonic and quantum dot lasers, biosensors, and energy conversion. The core innovation lies in fabrication, optical probing and simulation of novel nanoscale hybrid structures and architectures whose geometrical parameters can be systematically tuned. To accomplish this goal requires a concerted effort in nanofabrication, coherent optical spectroscopy and theoretical modeling that is provided by an international collaboration between an American and German research team. The US team consists of researchers at the University of Arkansas who are partners with the University of Oklahoma in an NSF-supported Materials Research Science and Engineering Center. This team is especially talented in the growth by molecular beam epitaxy, characterization by scanning tunneling microscopy, and the characterization of the optical behavior of nanostructures and the interactions between them. The German team consists of researchers at the Institut für Physik, at the University of Oldenburg, who have many years of experience in the development and application of ultrafast and nanoscale optical spectroscopy tools to study the coherent optical behavior of nanostructures. Together, both teams have the experience, talent, and infrastructure needed to develop a detailed microscopic understanding of the interactions between the elementary optical excitations of a semiconductor quantum dot, or exciton, and the elementary optical excitation of a metal nanoparticle (MNP), or surface plasmon polariton, as well as the coherent and incoherent resonant coupling between a single quantum dot and quantum well. Student exchange will also play a significant part of the collaborative effort to accomplish the research goals. For example, students will spend one to two months each year with their international partner pursuing and advancing the understanding of the coupling in hybrid nanostructures and their corresponding thesis research. Since students will eventually work in a global market there is no better preparation for international collaboration. In addition, by working with a team on an international scale there is a new dimension added to student teamwork, requiring students to handle collaboration that is remote, cross-cultural, and linguistically challenging. Students will also be the central element in an aggressive outreach plan to both K-12 American and German students. Their participation will further provide an opportunity for the sharing of cultures.