Ultrafast Dynamics and Energy Relaxation for Nanoporous Gold Materials: Lower Porosity and Faster Energy Exchange

Abstract

Light interacting with nanoporous gold (NPG) brings versatile applications, requiring the fundamental understanding the dynamic process of how this nanoporous material converts photon energy. In this work, we conducted comprehensive research to capture the ultrafast dynamic process of NPG with different structures responding to different light wavelengths and intensities. The elevated annealing temperature was controlled to adjust the nanostructures, mainly featuring the size of the ligament and the porosity. Ultrafast dynamic results showed that the energy exchange is faster in electron–electron coupling and slower in electron–phonon coupling when the samples were excited at plasmonic resonance (∼2.21 eV) and a higher excitation energy compared to other light parameters. A smaller ligament size and higher porosity gave rise to larger time constants of both electron–electron and electron–phonon coupling. For vibration modes, the low-frequency component dominates the vibration modes. The results suggest that light and structure parameters could significantly alter the light-induced electronic excitation dynamics inside NPG and thus is fundamentally important for the light-modulated properties of NPG materials.

Investigation of charge carrier dynamics in a Ti3C2Tx MXene for ultrafast photonics applications

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Rapid eradication of antibiotic-resistant bacteria and biofilms by MXene and near-infrared light through photothermal ablation

“…In this work, we employed a homemade femtosecond transient absorption system as reported before [36,37]. In brief, our experimental setup was as following: a broadband oscillator (Coherent Vitesse, 1 W) generated seed pluses (20 fs pulse width, 80 MHz) with a center wavelength of 800 nm (80 nm bandwidth).…”

Electro-Chemical Actuation of Nanoporous Metal Materials Induced by Surface Stress

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