Stress relief from missing dimers on Bi/Si(0 0 1)

Based on first principles calculations, we studied the structural properties of group V elements P, As, Sb and Bi on the Si(0 0 1) surface. For one monolayer of the group V atoms on the Si(0 0 1) substrate, stress and stress anisotropy scaled almost linearly with atomic size, implying that the obvious source of surface stress was atomic size effect. We found that stress relief was responsible for the (2 × n) reconstruction of Sb and Bi on the Si(0 0 1) surface. Stress anisotropy could be tuned through zero and reversed in sign with n ranging from 10 to 5.