The migration kinetics of O inserted into the surface back-bond network of H-terminated Si quantum dots was examined. Diffusion both inward and lateral to the surface was modelled. It was found that the activation energies for migration generally far exceeded the thermal energy available at room temperature and, thermodynamically, the production of sub-surface O was not favored. Surface dangling bonds significantly affected migration barriers, stabilized sub-surface threefold coordination of O, and surface bridging structures that red-shifted the onset of optical transitions. It was also shown that ionization enhanced O migration of a fully passivated dot, but it did not favor sub-surface O.

Density Functional Study of Oxygen Migration Processes for Silicon Quantum Dots. R.J.Eyre, J.P.Goss, P.R.Briddon: Physical Review B, 2007, 76[24], 245325 (6pp)