Fabrication of a Au/Si nanocomposite structure by nanosecond pulsed laser irradiation

Abstract

A gold/silicon nanocomposite structure (NCS) was formed on a Si(100) surface bynanosecond pulsed laser irradiation. The Au/Si NCS contained both Au nanoparticles(NPs) and Au–Si alloy layers. We report that the use of laser irradiation to form Au NPscomprises two competing processes: a top-down effect involving decomposition intosmaller NPs and a bottom-up effect involving self-assembly or self-organization intolarger NPs. The formation of the periodic structure involved self-organization,i.e., the bottom-up effect, and was observed in situ using a pulsed-laser-equippedhigh-voltage electron microscope. The NCS formed by laser irradiation can becontrolled by adjusting the laser energy density and the number of laser pulses.