Transient localized surface plasmon induced by femtosecond interband excitation in gold nanoparticles

Scientific Reports
Xinping ZhangZhiyi Wei

Abstract

Localized surface plasmon resonance (LSPR) is essentially a collective oscillation of free electrons in nanostructured metals. Interband excitation may also produce conduction-band electrons above the Fermi level. However, a question here is whether these excited electrons can take part in plasmonic oscillation. To answer this question, femtosecond pump-probe measurements on gold nanoparticles were performed using interband excitation, where the pump pulse produced a large amount of electrons in the sp-conduction band and left holes in the d-band. Probing by transient absorption spectroscopy, we resolved an induced LSPR feature located at a red-shifted spectrum. This feature cannot be observed for a pumping photon energy lower than the threshold for interband transition. The commonly observed red-shift or broadening of LSPR spectrum due to electron-electron and electron-phonon scattering under strong optical excitation can be ruled out for understanding this feature by a comparison between the plasmonic dynamics at a pump above and below the interband-transition threshold. In particular, a "holding" time of about 1 ps was resolved for the interband-excitation-induced electrons to relax to the LSPR oscillation.

Citations

Feb 26, 2020·Physical Chemistry Chemical Physics : PCCP·Anna Rosa ZiefussAnton Plech
Mar 18, 2020·Science Advances·Xinping ZhangXiaoyan Song
May 6, 2019·Optics Express·Yevhenii M MorozovZi-Chun Le
May 6, 2021·Nanomaterials·Ayesha SharifGerard M O'Connor

❮ Previous
Next ❯

Methods Mentioned

BETA
surface plasmon resonance
electron-electron scattering

Related Concepts

Related Feeds

Cardiac Conduction System

The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.