Radiative and Ultrafast Non-Radiative Electronic Relaxation in Individual and Assembled Nobel Metallic Nanoparticles of Different Shapes
Project Information
Funding Information
| Country | USA |
| Anticipated Total Funding | $761,997.00 |
| Annual Funding | $126,999.50 |
| Funding Source | NSF |
| Funding Mechanism | Extramural |
| Funding Sector | Government |
| Start Year | 2002 |
| Anticipated End Year | 2008 |
Abstract/Summary
This project aims to study radiative and nonradiative properties of individual gold nanodots and nanorods and their self-assembly properties from solution. One aspect is to measure properties for silver and copper individual nanoparticles in solution and in different liquid and solid media. The second is to examine the properties of self-assembled forms of either gold, silver, or copper nanoparticles having different shapes. Different methods for self-assembly of these nanoparticles from solution will be examined. For the individual nanoparticles, the project will address: 1) the dependence of electron-phonon and phonon-phonon relaxation on the atomic mass of the metal; 2) the effect of the medium in which these nanoparticles are dissolved on the electron-phonon and phonon-phonon relaxation; and 3) the laser photothermal transformation of nanoparticles of different shapes. Because of the close proximity of the metallic nanoparticles they are able to couple electronically via the plasmon resonance, changing in turn the optical properties of the assembled structures compared to those of the individual particles. Accordingly, the proposed research will explore radiative and ultrafast nonradiative relaxation properties as a function of the particle type, size and shape of the multi-particle structure. This is very important when incorporating metallic nanoparticles into solid-state devices. By using time-resolved femtosecond pump-probe transient spectroscopy and microscopy, the dynamics of heating, cooling and structural transformation will be examined for the assembled structures of the individual particles. %%% The study of the electron dynamics of individual metallic nanoparticles is of great importance to fundamental physics and for their potential use in nanotechnology. Understanding the electron energy conversion into lattice phonons and the interactions of the hot metallic nanoparticles with their surrounding environment is of great importance for possible future applications. These areas are of high interest to industry, and the proposed studies will train these students to contribute to materials science and engineering areas of significant national interest.
