Transient absorption with a femtosecond tunable excitation pump reveals the emission kinetics of color centers in amorphous silica
- Authors: de Michele V.; Sciortino A.; Messina F.; Cannas M.; Boukenter A.; Marin E.; Girard S.; Ouerdane Y.
- Publication year: 2021
- Type: Articolo in rivista
- OA Link: http://hdl.handle.net/10447/522238
Abstract
We report a set of femtosecond (fs) transient absorption (TA) measurements following the dynamics of the so-called nonbridging oxygen hole center in silica, a model color center in wide bandgap amorphous solids, characterized by a very large Stokes shift between the UV excitation and its associated red emission at 1.9 eV. The changes in the TA spectrum were probed in the UV-visible range at various delays after photoexcitation and analyzed as a function of the UV excitation energy, in single-photon absorption conditions. The combination of the experiments helps to clarify the defect photocycle, highlighting how TA measurements with tunable UV excitation could represent a powerful tool to investigate the dynamics of color centers embedded in transparent materials. © 2021 Optical Society of America