Ultrafast electron-lattice thermalization in copper and other noble metal nanoparticles
D’ADDATO, Sergio
Università degli Studi di Modena e Reggio Emilia = University of Modena and Reggio Emilia [UNIMORE]
< Réduire
Università degli Studi di Modena e Reggio Emilia = University of Modena and Reggio Emilia [UNIMORE]
Langue
en
Article de revue
Ce document a été publié dans
Journal of Physics: Condensed Matter. 2019-02-27, vol. 31, n° 8, p. 084001 (1-11)
IOP Publishing
Résumé en anglais
Using time-resolved ultrafast pump-probe spectroscopy we investigated the electron-lattice energy transfer in small copper nanospheres with diameters ranging from 3.2 to 23 nm, either embedded in a glass or dispersed in a ...Lire la suite >
Using time-resolved ultrafast pump-probe spectroscopy we investigated the electron-lattice energy transfer in small copper nanospheres with diameters ranging from 3.2 to 23 nm, either embedded in a glass or dispersed in a solvent. Electron-lattice scattering rate is shown to increase with size reduction, in agreement with our previous results obtained on gold and silver nanoparticles in the low excitation regime. We attribute this effect to the reduction of the screening efficiency of electron–phonon interactions close to the nanoparticle surface. To understand the discrepancy between the results on the electron-lattice scattering in different metals reported in the literature (reduction, no dependence or increase with nanoparticle size), we discuss the experimental conditions required for the accurate determination of electron-lattice energy transfer time from time-resolved investigations in the weak and strong excitation regimes and present power-dependent experiments on gold nanospheres in solution. Our findings are derived from a theoretical analysis based on the two-temperature model predictions and on a complete modeling of the nanoparticle transient extinction cross-section through the resolution of Boltzmann equation in the presence of hot electrons.< Réduire
Mots clés en anglais
electron-lattice interactions
two-temperature model
ultrafast electron dynamics
pump-probe spectroscopy
copper nanoparticles
Origine
Importé de halUnités de recherche