Quantitative Ultrafast Electron‐Temperature Dynamics in Photo‐Excited Au Nanoparticles. Issue 26 (1st June 2021) - Sygletou, Maria
Abstract: The femtosecond evolution of the electronic temperature of laser‐excited gold nanoparticles is measured, by means of ultrafast time‐resolved photoemission spectroscopy induced by extreme‐ultraviolet radiation pulses. The temperature of the electron gas is deduced by recording and fitting high‐resolution photo emission spectra around the Fermi edge of gold nanoparticles providing a direct, unambiguous picture of the ultrafast electron‐gas dynamics. These results will be instrumental to the refinement of existing models of femtosecond processes in laterally‐confined and bulk condensed‐matter systems, and for understanding more deeply the role of hot electrons in technological applications. Abstract : For the first time a direct measurement of the ultrafast electron‐temperature dynamics in plasmonic gold (Au) nanoparticles (NPs) in the first femtoseconds (fs) after the excitation is reported. By performing ultrafast state‐of‐the‐art photoemission measurements with high temporal and unprecedented spectral resolution, the electron‐temperature evolution of photo‐excited Au NPs on the femtosecond time scale is detected, in a totally model‐independent fashion.