Ultrafast laser-induced decomposition for selective activation of GaAs

The manipulation of micro/nanostructures to customise their inherent material characteristics has garnered considerable attention.In this study,we present the selective activation of gallium arsenide(GaAs)via ultrafast laser-induced decomposition,which correlates with the emergence of ripples on the surface.This instigated a pronounced enrichment in the arsenic(As)concentration around the surface while inducing a depletion of gallium(Ga)at the structural depth.Theoretical simulations based on first principles exhibited a robust inclination towards the phase separation of GaAs,with the gasification of As-As pairs proving more facile than that of Ga-Ga pairs,particularly above the melting point of GaAs.As an illustrative application,a metal-semiconductor hybrid surface was confirmed,showing surface chemical bonding and surface-enhanced Raman scattering(SERS)through the reduction of silver ions on the laser-activated pattern.This laser-induced selective activation holds promise for broader applications,including the controlled growth of Pd and the development of Au/Ag alloy-based platforms,and thereby opens innovative avenues for advancements in semiconductors,solar cell technologies,precision sensing,and detection methodologies.