Hydrogen-bonded array of NH2 on the Si(100) surface

Abstract

The atomic and electronic structures of the dissociative adsorption of ammonia on the Si(100)-(2x1) surface are studied by first-principles calculations. We find that the hydrogen-bonding interactions between the dissociated NH2 species favor the "gauche'' model over the existing models. This strong attractive force can form a one-dimensional hydrogen-bonded array of NH2 along the Si dimer row. Our analysis identifies three NH2-derived electronic states, composed of one delocalized state along the dimer row and two localized molecular orbitals.