title: Ultraviolet photoluminescence of silanol species in mesoporous silica.
abstract: The optical properties of sol-gel synthesized porous silica excited by synchrotron radiation in the 4-10 eV range of samples with different porosity at 8 K and room temperature are reported. The analysis of the ultraviolet photoluminescence indicate the contributions of two different emitting centers. The spectral and temporal characteristics of the two luminescence bands are reported: emission peaks at about 3.7 and 4.0 eV, excitation channels around 5.4-5.7 and 6.2-6.5 eV, and mean lifetimes of about 17 and 2 ns, respectively. The analysis of the optical properties in samples with different porosity allows us to propose a silanol-related model for the two centers.
authors.affiliation: Dipartimento di Fisica, Università di Cagliari and INFM UdR Cagliari, Cittadella Universitaria, SP no 8 Km 0.700, I-09042 Monserrato (Ca), Italy. cm.carbonaro@dsf.unica.it
authors.forename: Carlo M
authors.initials: CM
authors.lastname: Carbonaro
authors.forename: Francesca
authors.initials: F
authors.lastname: Clemente
authors.forename: Riccardo
authors.initials: R
authors.lastname: Corpino
authors.forename: P Carlo
authors.initials: PC
authors.lastname: Ricci
authors.forename: Alberto
authors.initials: A
authors.lastname: Anedda