Journal ArticleDOI
Decay kinetics of the 4.4-eV photoluminescence associated with the two states of oxygen-deficient-type defect in amorphous SiO2.
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TLDR
In this article, the first observation of 4.4 eV photoluminescence (PL) decay in an oxygen-deficient-type silica excited with ultraviolet and vacuum ultraviolet photons from synchrotron radiation is presented.Abstract:
We present the first observation of 4.4 eV photoluminescence (PL) decay in an oxygen-deficient-type silica excited with ultraviolet and vacuum ultraviolet photons from synchrotron radiation. The lifetime of the 4.4 eV PL is 4.2, 4.3, and 2.1 ns for the 5.0, 6.9, and 7.6 eV excitations, respectively, indicating the presence of multiple decay channels. This can be explained by an energy diagram involving the interconversion between two states of the oxygen-deficient-type defect.read more
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Journal ArticleDOI
Optically active oxygen-deficiency-related centers in amorphous silicon dioxide
TL;DR: In this paper, the spectroscopic properties, structure and interconversions of optically active oxygen-deficiency-related point defects in vitreous silica are reviewed.
Journal ArticleDOI
Overview of radiation induced point defects in silica-based optical fibers
Sylvain Girard,Antonino Alessi,Nicolas Richard,Layla Martin-Samos,Vincenzo De Michele,Vincenzo De Michele,Luigi Giacomazzi,Simonpietro Agnello,Diego Di Francesca,Adriana Morana,Blaž Winkler,Imène Reghioua,Philippe Paillet,Marco Cannas,Thierry Robin,Aziz Boukenter,Youcef Ouerdane +16 more
TL;DR: In this article, a review of the main classes of silica-based optical fibers are presented: radiation tolerant pure-silica core or fluorine doped optical fibers, germanosilicate optical fibers and radiation sensitive phosphosilicates and aluminosa-ilimideal optical fibers.
Journal ArticleDOI
Chemistry, textures and physical properties of quartz - geological interpretation and technical application
TL;DR: Quartz is one of the most abundant minerals in the Earth's crust and the most important silica mineral, occurring in large amounts in igneous, metamorphic and sedimentary rocks.
Journal ArticleDOI
Trapped-electron centers in pure and doped glassy silica: A review and synthesis
TL;DR: In this article, the authors review half a century of research on radiation-induced point defects in pure and doped glassy silica and its crystalline polymorph α quartz, placing emphasis on trapped-electron centers.
Book ChapterDOI
Defect Related Luminescence in Silicon Dioxide Network: A Review
Abstract: The discovery of strong luminescence at room temperature from silicon cluster has attracted an enormous attention in recent years due to its potential applications in Si-based optoelectronic devices, especially blue and UV luminescence devices. Several studies have addressed the question of augmentation and stabilization of luminescence emission with different treatments, such as electron irradiation, thermal treatments and ion implantations. Even though observed visible light can be explained by the quantum confinement (QC) effect, many experimental results obey to the QC model supported surface state. Theoretically, the effects of quantum confinement on band gap of silicon indicate that it should be possible to obtain a blue light or shorter wavelength photons from the porous silicon if the silicon crystal size can be reduced to a certain value, e.g. to the diameter of 2-5 nm. However, it is rather difficult in practice to obtain a blue/white luminescence even when nanocrystals with diameters smaller than 2.0 nm are present. Some authors attributed this difficulty to the formation of surface Si–O bonds, which lead to mid-band gap trapped electrons and hole exciton states and thereby remove the dependency of the luminescence on cluster size. But in this case a luminescence emission was obtained in the red and yellow regions. It was found that some post-treatments such as anodic oxidation and oxidation in air could reduce the effective size of the Si nanocrystallites, thus causing a blue shift of the luminescence spectrum. If the red-yellow emission of the PS could be combined with a blue/green emission by modification of the PS surface such as oxidation or metal coating, it would be possible to obtain white light. This would mean an economical route to silicon based LEDs. Silicon dioxide, SiO2, is widely distributed in the environment, and is present in the form of sand on all beaches and deserts. It is the starting material for the production of silicate glasses and ceramics. It may occur in crystalline or amorphous form, and is found naturally in impure forms such as sandstone, silica sand or quartz. Its specific gravity and melting point depend on the crystalline structure. Silica is known to occur in many crystalline phases or modes (┙-quartz, ┚-quartz, ┙-cristobalite, ┚-cristobalite, ┙-tridymite, ┚tridymite, ┛-tridymite, coesite, melanophlogopite, keatite, fasriges, stishovite, chalcedon, agate, moganite, and others) besides some amorphous phases (opal, hyalite, sintered pearl, lechateierite, natural silica glass) [Fanderlik 1991]. Silicon dioxide is not only one of the most abundant materials on earth as mentioned, but also a critical material component of considerable technological importance. Today's modern electronics greatly depends on silicon dioxide for the manufacture of semiconductors and microelectronic devices, besides