The origin of electron trapping and negative charging of hydroxylated silica surfaces is predicted based on accurate quantum-mechanical calculations. The calculated electron affinities of the two dominant neutral paramagnetic defects, the nonbridging oxygen center, , and the silicon dangling bond, , demonstrate that both defects are deep electron traps and can form the corresponding negatively charged defects. We predict the structure and optical absorption energies of these diamagnetic defects.
- Received 5 April 2007
©2007 American Physical Society