DOI: 10.3390/inorganics14110276 ISSN: 2304-6740
Ab Initio Modeling of Optical Excitations Associated with Intrinsic Defects in a-SiO2
Fedor V. Grigoriev, Vladimir B. Sulimov, Alexander V. TikhonravovA systematic study of the structure and optical properties of diamagnetic neutral defects in silicon dioxide is conducted using ab initio quantum-chemical methods. It is found that the =Si---Si= defect, formed by two weakly bonded twofold-coordinated silicon atoms, and the =Si(O2) defect containing a dioxasilirane group are capable of absorbing intense visible-range laser radiation. The potential contribution of these defects to the initiation of laser-induced damage is discussed. It is also shown that bond elongation in certain defects leads to a reduction in excitation energies, shifting them from the ultraviolet to the visible range.