Size-dependent oxidation of hydrogenated silicon clusters

We show explicitly the size-dependent chemical reactivity of hydrogenated silicon clusters reacting with water. A unique trend of decreasing reactivity with decreasing cluster size has been deduced from reaction energetics, frontier orbital analysis, and chemical reaction rates determined by the transition state theory in conjunction with ab initio calculations at Hartree-Fock and Møller-Plesset perturbation levels of theory, for water reaction with both dihydride and trihydride silicon configurations. This study indicates the possibility of fabricating stable hydrogenated silicon structures by reducing their size to nanometers. © 2002 American Institute of Physics.