In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Prof. John M. Papanikolas of the University of North Carolina at Chapel Hill will combine pump-probe methodologies with nonlinear microscopy to investigate the charge carrier dynamics in one-dimensional nanostructures, networks and nanodevices on ultrafast time scales. The goal of the project is to elucidate the relation between the carrier dynamics and the local shape of the object, an issue that is fundamentally important and critical to understanding many problems in nanoscience and nanotechnology. Variation in behavior from structure-to-structure, and even between different spatial locations within the same structure, is a hallmark of complexity and its presence poses a major challenge to those wishing to exploit nanoscale materials in a variety of device applications. The project will develop a new microscopy technique that will excite a nanostructure in one spatial location and probe the dynamics in another, on time scales ranging from femtoseconds to nanoseconds. Professor Papanikolas and his students will use this spatially-separated pump-probe microscope to visualize charge carrier migration through individual nanorods and networks. This project will contribute to our understanding of complex nanosystems while promoting teaching, training, and learning in the context of a research program. Graduate, undergraduate and high school students will participate in this research. They will develop the technologically sophisticated instrumentation, apply those methods to the study of single nanostructures, take part in the communication of their results, and participate in the development of activities for middle school students that highlight their research.
