Probing Electronic Structure and Energy Transfer in Protected Metal Nanoparticles by Mass-Selective Spectroscopy
Abstract
Metal nanoparticles have tremendous potential to reshape a wide range of technologies incatalysis, photovoltaics, nanoscale electronics, and sensors. The electronic structure of ananoparticle controls the motions of electrons in them, which in turn controls the efficiency oftransferring charge into and out of them. It is strongly dependent on the chemical properties ofthe ligand molecules, but the exact way in which the ligands perturb the electronic structure hasnot been established. This is partly due to the fact that these particles are typically created with arange of sizes and compositions, washing out details of any individual compositions andpreventing systematic studies.This project aims to establish a framework to understand the electronic structure of metalnanoparticles surrounded by protecting ligand molecules. This will be achieved by applying anew technique that allows optical spectra to be recorded from nanoparticles with preciselyselected compositions and temperatures down to 10 K. This approach avoids blurring due tocompositional and environmental heterogeneity and thermal effects, producing spectra withnarrow, resolved peaks. These advantages permit systematic studies of the effects of size andligand molecular properties, where subtle changes to spectra would be essentially undetectable intypical experiments. It also allows charge transfer between two linked nanoparticles of exactlyknown compositions to be studied in unprecedented detail.The outcome of this project will be a new framework for how the electronic properties of metalnanoparticles are affected by the protecting ligand molecules, and further, how these propertiesconnect to charge transfer. This framework can be used as a guide for efforts to engineernanostructured systems that depend on moving energy using metallic nanoparticles.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2017
- Source ID
- FA95501710373
Entities
People
- Christopher J Johnson
Organizations
- Air Force Office of Scientific Research
- Research Foundation for the State University of New York
- United States Air Force