Scientists capture the split-second birth of energy-harvesting particles in gold
Researchers have directly observed how gold nanoparticles convert light into energetic electrons—a process lasting mere trillionths of a second. The discovery could unlock more efficient solar cells, cancer therapies, and chemical manufacturing by revealing how to better capture these fleeting energy carriers before they dissipate.
Originaltitel: The dynamics of plasmon-induced hot carrier creation in colloidal gold
<p>The generation and dynamics of plasmon-induced hot carriers in gold nanoparticles offer crucial insights into nonequilibrium states for energy applications, yet the underlying mechanisms remain experimentally elusive. Here, we leverage ultrafast X-ray absorption spectroscopy (XAS) to directly capture hot carrier dynamics with sub-50 fs temporal resolution, providing clear evidence of plasmon decay mechanisms. We observe the sequential processes of Landau damping (similar to 25 fs) and hot carrier thermalization (similar to 1.5 ps), identifying hot carrier formation as a significant decay pathway. Energy distribution measurements reveal carriers in non-Fermi-Dirac states persisting beyond 500 fs and observe electron populations exceeding single-photon excitation energy, indicating the role of an Auger heating mechanism alongside traditional impact excitation. These findings deepen the understanding of hot carrier behavior under localized surface plasmon resonance, offering valuable implications for applications in photocatalysis, photovoltaics, and phototherapy. This work establishes a methodological framework for studying hot carrier dynamics, opening avenues for optimizing energy transfer processes in nanoscale plasmonic systems.</p>