Radiation-induced spectral modifications of the 5 eV excited photoluminescence (PL) of oxygen vacancies have been found in a nanostructured silica-based material. This system, made up of SnO2 nanocrystals embedded in amorphous SiO2, is generated by nano-clustering in oversaturated Sn-doped silica produced by sol-gel method. Treatment in oxygen-poor atmosphere introduces oxygen deficiency in the glassy host and a photo-reactive SnO-like interphase at the SnO2 nanocrystal surface. PL measurements initially show native PL activity at 2.7 eV excited at 5 eV, ascribable to oxygen vacancies in intrinsic two-fold coordinated Si sites. Prolonged UV irradiation at 4.7 eV (fourth harmonic of Nd-YAG pulsed laser) gives rise to extrinsic PL activity at 3.1 eV, ascribable to Sn-variant of oxygen vacancy. The results suggest that the UV irradiation causes a progressive release of Sn from the nanophase surface to the glassy network in oxygen vacancy sites. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).
Brovelli, S., Chiodini, N., Lauria, A., Meinardi, F., Paleari, A. (2007). Native and radiation-induced two-fold coordinated sites in nanostructured SnO2:SiO2. PHYSICA STATUS SOLIDI. C, CURRENT TOPICS IN SOLID STATE PHYSICS, 4(3), 822-825 [10.1002/pssc.200673832].
Native and radiation-induced two-fold coordinated sites in nanostructured SnO2:SiO2
BROVELLI, SERGIO;CHIODINI, NORBERTO;LAURIA, ALESSANDRO;MEINARDI, FRANCESCO;PALEARI, ALBERTO MARIA FELICE
2007
Abstract
Radiation-induced spectral modifications of the 5 eV excited photoluminescence (PL) of oxygen vacancies have been found in a nanostructured silica-based material. This system, made up of SnO2 nanocrystals embedded in amorphous SiO2, is generated by nano-clustering in oversaturated Sn-doped silica produced by sol-gel method. Treatment in oxygen-poor atmosphere introduces oxygen deficiency in the glassy host and a photo-reactive SnO-like interphase at the SnO2 nanocrystal surface. PL measurements initially show native PL activity at 2.7 eV excited at 5 eV, ascribable to oxygen vacancies in intrinsic two-fold coordinated Si sites. Prolonged UV irradiation at 4.7 eV (fourth harmonic of Nd-YAG pulsed laser) gives rise to extrinsic PL activity at 3.1 eV, ascribable to Sn-variant of oxygen vacancy. The results suggest that the UV irradiation causes a progressive release of Sn from the nanophase surface to the glassy network in oxygen vacancy sites. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).
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