DFT study of spin states on bare and partially hydrogenated Si(111) and Si(100) surfaces

Abstract

Density functional theory calculations have been performed on slabs of crystalline silicon. The unreconstructed (111) and 2 x 1 reconstructed (100) surfaces have been studied. Starting from surfaces wholly passivated with hydrogen, selected sites were unpassivated to yield small clusters of unpaired spins corresponding to dangling bonds. A range of spin densities were converged for each cluster of dangling bonds to investigate the energetics of different spin patterns in these isolated clusters of dangling bonds. The results were broadly consistent with antiferromagnetic coupling between the spins, only mildly affected by the geometric and electronic effects of the surrounding surface bond passivation. (Figure Presented). Show more