Photophysics of Nanometer Sized Metal Particles: Electron−Phonon Coupling and Coherent Excitation of Breathing Vibrational Modes
| Autor: | Gregory V. Hartland, and Arnim Henglein, Jose H. Hodak |
|---|---|
| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry B. 104:9954-9965 |
| ISSN: | 1520-5207 1520-6106 |
| DOI: | 10.1021/jp002256x |
| Popis: | The wide variety of applications of metal nanoparticles has motivated many studies of their properties. Some important practical issues are how the size, composition and structure of these materials affect their catalytic and optical properties. In this article we review our recent work on the photophysics of metal nanoparticles. The systems that have been investigated include Au particles with sizes ranging from 2 nm diameter (several hundred atoms) to 120 nm diameter, and bimetallic core−shell particles composed of Au, Ag, Pt and/or Pb. These particles, which have a rather narrow size distribution, are prepared by radiolytic techniques. By performing time-resolved laser measurements we have been able to investigate the coupling between the electrons and phonons in the particles, and their low frequency “breathing” modes. These experiments show that for Au the time scale for electron−phonon coupling does not depend on size, in contrast to metals such as Ga and Ag. On the other hand, the frequency of the ... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|