Electron trapping at point defects on hydroxylated silica surfaces.
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, identical with Si-O*, and the silicon dangling bond, identical with Si*, 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.
Giordano
Livia
L
Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R. Cozzi, 53-20125 Milano, Italy.
Sushko
Peter V
PV
Pacchioni
Gianfranco
G
Shluger
Alexander L
AL