Porosity-moderated ultrafast electron transport in Au nanowire networks

We demonstrate for first time the ultrafast properties of a newly formed porous Au nanostructure. The properties of the porous nanostructure are compared with those of a solid gold film using time-resolved optical spectroscopy.The experiments suggest that under the same excitation conditions the relaxation dynamics are slower in the former. Our observations are evaluated by simulations based on a phenomenological rate equation model. The impeded dynamics has been attributed to the porous nature of the structure in the networks, which results in reduced efficiency during the dissipation of the laser-deposited energy. Importantly,the porosity of the complex three-dimensional nanostructure is introduced as a geometrical control parameter of its ultrafast electron transport