1
|
Giacomazzi L, Martin-Samos L, Richard N, Ceresoli D, Alessi A. Identification of paramagnetic centers in irradiated Sn-doped silicon dioxide by first-principles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:215502. [PMID: 38364269 DOI: 10.1088/1361-648x/ad2a0c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 02/16/2024] [Indexed: 02/18/2024]
Abstract
We present a first-principles investigation of Sn paramagnetic centers in Sn-doped vitreous silica based on calculations of the electron paramagnetic resonance (EPR) parameters. The present investigation provides evidence of an extended analogy between the family of Ge paramagnetic centers in Ge-doped silica and the family of Sn paramagnetic centers in Sn-doped silica for SnO2concentrations below phase separation. We infer, also keeping into account the larger spin-orbit coupling of Sn atoms with respect to Ge atoms, that a peculiar and highly distorted three-fold coordinated Sn center (i.e. the Sn forward-oriented configuration) should give rise to an orthorhombic EPR signal of which we suggest a fingerprint in the EPR spectra recorded by Chiodiniet al(2001Phys. Rev.B64073102). Given its structural analogy with theEα'and Ge(2) centers, we here name it as the 'Sn(2) center'. Moreover, we show that the single trapped electron at a SnO4tetrahedron constitutes a paramagnetic center responsible for the orthorhombic EPR signal reported in Chiodiniet al(1998Phys. Rev.B589615), confuting the early assignment to a distorted variant of the Sn-E' center. We hence relabel the latter orthorhombic EPR signal as the 'Sn(1) center' due to its analogy to the Ge(1) center in Ge-doped silica.
Collapse
Affiliation(s)
- L Giacomazzi
- CNR-IOM - Istituto Officina dei Materiali, National Research Council of Italy, c/o SISSA Via Bonomea 265, Trieste IT-34136, Italy
| | - L Martin-Samos
- CNR-IOM - Istituto Officina dei Materiali, National Research Council of Italy, c/o SISSA Via Bonomea 265, Trieste IT-34136, Italy
| | - N Richard
- CEA, DAM, DIF, F-91297 Arpajon, France
- Université Paris-Saclay, CEA, Laboratoire Matière en Conditions Extrêmes, F-91680 Bruyères-le-Châtel, France
| | - D Ceresoli
- CNR-SCITEC - Istituto di Scienze e Tecnologie Chimiche "G. Natta", National Research Council of Italy, via C. Golgi 19, Milano 20133, Italy
| | - A Alessi
- Laboratoire des Solides Irradiés (LSI), CEA/DRF/IRAMIS, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91120 Palaiseau, France
| |
Collapse
|
2
|
Photocycle of point defects in highly- and weakly-germanium doped silica revealed by transient absorption measurements with femtosecond tunable pump. Sci Rep 2022; 12:9223. [PMID: 35654982 PMCID: PMC9163034 DOI: 10.1038/s41598-022-13156-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/06/2022] [Indexed: 11/28/2022] Open
Abstract
We report pump-probe transient absorption measurements addressing the photocycle of the Germanium lone pair center (GLPC) point defect with an unprecedented time resolution. The GLPC is a model point defect with a simple and well-understood electronic structure, highly relevant for several applications. Therefore, a full explanation of its photocycle is fundamental to understand the relaxation mechanisms of such molecular-like systems in solid state. The experiment, carried out exciting the sample resonantly with the ultraviolet (UV) GLPC absorption band peaked at 5.1 eV, gave us the possibility to follow the defect excitation-relaxation dynamics from the femto-picosecond to the nanosecond timescale in the UV–visible range. Moreover, the transient absorption signal was studied as a function of the excitation photon energy and comparative experiments were conducted on highly- and weakly-germanium doped silica glasses. The results offer a comprehensive picture of the relaxation dynamics of GLPC and allow observing the interplay between electronic transitions localized on the defect and those related to bandgap transitions, providing a clear evidence that the role of dopant high concentration is not negligible in the earliest dynamics.
Collapse
|
3
|
Hongisto M, Veber A, Petit Y, Cardinal T, Danto S, Jubera V, Petit L. Radiation-Induced Defects and Effects in Germanate and Tellurite Glasses. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E3846. [PMID: 32878282 PMCID: PMC7504562 DOI: 10.3390/ma13173846] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 01/13/2023]
Abstract
This review focuses on the radiation-induced changes in germanate and tellurite glasses. These glasses have been of great interest due to their remarkable potential for photonics, in terms of extended transmission window in the mid-infrared, ability of rare-earth loading suitable with a laser, and amplification in the near- and mid-infrared or high nonlinear optical properties. Here, we summarize information about possible radiation-induced defects, mechanisms of their formation, and the influence of the glass composition on this process. Special attention is paid to laser-induced structural modification of these glasses, including possible mechanisms of the laser-glass interaction, laser-induced crystallization, and waveguide writing. It is shown that these methods can be used for photostructuring of the glass and have great potential for practical applications.
Collapse
Affiliation(s)
- Mikko Hongisto
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (A.V.); (L.P.)
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Alexander Veber
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (A.V.); (L.P.)
| | - Yannick Petit
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Thierry Cardinal
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Sylvain Danto
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Veronique Jubera
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Laeticia Petit
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (A.V.); (L.P.)
| |
Collapse
|
4
|
Giacomazzi L, Martin-Samos L, Boukenter A, Ouerdane Y, Girard S, Alessi A, Gironcoli SD, Richard N. Photoactivated processes in optical fibers: generation and conversion mechanisms of twofold coordinated Si and Ge atoms. NANOTECHNOLOGY 2017; 28:195202. [PMID: 28345535 DOI: 10.1088/1361-6528/aa693b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this work we present an extensive investigation of nanoscale physical phenomena related to oxygen-deficient centers (ODCs) in silica and Ge-doped silica by means of first-principles calculations, including nudged-elastic band, electron paramagnetic resonance parameters calculations, and many-body perturbation theory (GW and Bethe-Salpeter equation) techniques. We show that by neutralizing positively charged oxygen monovacancies we can obtain model structures of twofold Si and Ge defects of which the calculated absorption spectra and singlet-to-triplet transitions are in excellent agreement with the experimental optical absorption and photo-luminescence data. In particular we provide an exhaustive analysis of the main exciton peaks related to the presence of twofold defects including long-range correlation effects. By calculating the reaction pathways and energy barriers necessary for the interconversion, we advance a double precursory origin of the [Formula: see text] and Ge(2) centers as due to the ionization of neutral oxygen monovacancies (Si-Si and Ge-Si dimers) and as due to the ionization of twofold Si and Ge defects. Furthermore two distinct structural conversion mechanisms are found to occur between the neutral oxygen monovacancy and the twofold Si (and Ge) atom configurations. Such conversion mechanisms allow to explain the radiation induced generation of the ODC(II) centers, their photobleaching, and also their generation during the drawing of optical fibers.
Collapse
Affiliation(s)
- Luigi Giacomazzi
- CNR-IOM/Democritos National Simulation Center, Istituto Officina dei Materiali, c/o SISSA, via Bonomea 265, I-34136 Trieste, Italy
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Ha NN, Giang NT, Thuy TTT, Trung NN, Dung ND, Saeed S, Gregorkiewicz T. Single phase Si1-xGex nanocrystals and the shifting of the E1 direct energy transition. NANOTECHNOLOGY 2015; 26:375701. [PMID: 26303286 DOI: 10.1088/0957-4484/26/37/375701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report preparation and characterization of Si1-xGex alloys with varied composition x of a large range from 0-1. The materials have been obtained by co-sputtering, followed by a heat treatment process at 600, 800, and 1000 °C for 30 min in a nitrogen gas atmosphere. X-ray diffraction data have revealed the formation of single-phase nanoparticles in the face-centered cubic (FCC) structure of Si1-xGex alloys. We found that lattice constant a of the Si1-xGex alloys increased linearly with the composition parameter x. Average diameters of the single-phase nanoparticles were estimated to be between 3-10 nm. Further evidence of FCC single-phase [Formula: see text] nanoparticles has been obtained by high resolution transmission electron microscopy. From absorption spectra, the gradual shift of the direct phononless transition identified for the E1 point in the Brillouin zone of bulk Ge is observed in single-phase Si1-xGex nanoparticles as a function of the composition parameter x.
Collapse
Affiliation(s)
- Ngo Ngoc Ha
- International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No.1 Dai Co Viet, Hanoi, Vietnam
| | | | | | | | | | | | | |
Collapse
|
6
|
Zyubin AS, Mebel AM, Lin SH. Optical Properties of Oxygen Vacancies in Germanium Oxides: Quantum Chemical Modeling of Photoexcitation and Photoluminescence. J Phys Chem A 2007; 111:9479-85. [PMID: 17629254 DOI: 10.1021/jp072314f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Photoabsorption and photoluminescence properties of single and double oxygen vacancy (OV and DOV) defects in quartz-like germanium oxide have been investigated by high-level ab initio calculations. It has been found that photoabsorption for these systems occurs at lower energies as compared to the analogous defects in SiO(2). For OV, the lowest electronic excitations with high oscillator strengths have energies of 6.7-7.0 eV, whereas for DOV, the lowest-energy photoabsorption band is calculated to be in the range of 5.5-5.9 eV. Significant geometry relaxation and large Stokes shift are inherent for these excited states and, as a result, their photoluminescence bands are predicted to peak at 3.1-3.3 eV for OV and at 2.6 eV for DOV. The double oxygen vacancy is suggested to be the most suitable candidate for generating bright blue photoluminescence observed experimentally for substoichiometric quartz-like GeO(2) nanowires, as the calculated optical properties of DOV are in close agreement with the features found in experiment.
Collapse
Affiliation(s)
- A S Zyubin
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan.
| | | | | |
Collapse
|
7
|
Self-alignment of Ge nano-particles in laser induced Bragg grating in Ge–B–SiO2 film. J Photochem Photobiol A Chem 2006. [DOI: 10.1016/j.jphotochem.2006.05.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
8
|
Zyubin AS, Mebel AM, Lin SH. Photoluminescence of oxygen-deficient defects in germanium oxides: A quantum chemical study. J Chem Phys 2006; 125:64701. [PMID: 16942299 DOI: 10.1063/1.2238866] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The photoabsorption and photoluminescence (PL) properties of the surface E(') center, -GeX(3), and the combined E(')-center-oxygen vacancy, X(3)Ge-GeX(2), defects in substoichiometric germanium oxides have been investigated by high-level ab initio calculations, including complete active space self-consistent field, multireference configuration interaction, and symmetry-adapted cluster configuration interaction methods. Both defects have been shown to give rise to photoabsorption bands between 4 and 6 eV. Geometry relaxation is significant and the Stokes shifts are large for all calculated excited states. A removal of an electron from the Ge-Ge bond leads to its destruction, whereas the creation of an electron hole at lone pairs of O atoms results in elongations of the Ge-O-Ge bonds in the corresponding bridges. Most often, deexcitations of excited electronic states proceed radiationlessly, through crossing points of their potential energy surfaces with those of the lower states. The -GeX(3) defect is able to generate several PL bands in the UV ( approximately 3 eV) and IR (1.2-1.4 and 0.5-0.6 eV) spectral ranges, whereas the X(3)Ge-GeX(2) defect gives only one red/orange PL band at 2.0-2.1 eV. No intense PL band was found in the blue spectral region of 2.5-2.7 eV, and the two defects are not likely to contribute to the intense blue photoluminescence observed for GeO(2) nanowires.
Collapse
Affiliation(s)
- A S Zyubin
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan
| | | | | |
Collapse
|
9
|
Cristoni S, Armelao L, Gross S, Seraglia R, Tondello E, Traldi P. Study of polycondensation reactions of Ge(OEt)(4) and Ge(OEt)(4)/Si(OEt)(4) by electrospray ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2002; 16:733-737. [PMID: 11921254 DOI: 10.1002/rcm.619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
10
|
|
11
|
Uchino T, Takahashi M, Yoko T. Structure and formation mechanism of Ge E (') center from divalent defects in Ge-doped SiO2 glass. PHYSICAL REVIEW LETTERS 2000; 84:1475-1478. [PMID: 11017546 DOI: 10.1103/physrevlett.84.1475] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/1999] [Indexed: 05/23/2023]
Abstract
We have performed ab initio quantum-chemical calculations on clusters of atoms modeling a divalent Ge defect in Ge-doped SiO (2) glasses. It has been found that the divalent Ge defect interacts with a nearby GeO (4) tetrahedron, forming complex structural units that are responsible for the observed photoabsorption band at approximately 5 eV. We have shown that these structural units can be transformed into two equivalent Ge E' centers by way of the positively charged defect center.
Collapse
Affiliation(s)
- T Uchino
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | | | | |
Collapse
|
12
|
Si J, Kitaoka K, Qiu J, Mitsuyu T, Hirao K. Optically encoded second-harmonic generation in germanosilicate glass by a femtosecond laser. OPTICS LETTERS 1999; 24:911-913. [PMID: 18073893 DOI: 10.1364/ol.24.000911] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Second-harmonic generation in germanosilicate glasses was encoded by coherent superposition of the 810-nm fundamental and the 405-nm second-harmonic light of a femtosecond laser. The difference spectra between the absorption spectra of the glasses before and after preparation were measured. An evident correlation between the induced second-order nonlinearity and the creation of a Ge electron center was observed, suggesting that a band-to-band transition by multiphoton absorption is probably responsible for the photoinduced second-harmonic generation.
Collapse
|
13
|
Quiquempois Y, Martinelli G, Niay P, Bernage P, Douay M, Bayon JF, Poignant H. Photoinscription of Bragg gratings within a germanosilicate fiber subjected to a high static electric field. OPTICS LETTERS 1999; 24:139-141. [PMID: 18071433 DOI: 10.1364/ol.24.000139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The kinetics of Bragg grating growth in germanosilicate fibers subjected to a high static electric field are compared with those obtained without any electric field. The gratings were written by exposure of the fiber core to laser light at 244 or 193 nm. These experiments gave some clues about the mechanisms responsible for both the photosensitivity in germanosilicate fibers and the nonlinear second-order UV-induced susceptibility in silica glasses. The refractive-index modulation proved to be significantly higher in the fibers subjected to an electric field. Furthermore, the change in the fiber's mean effective refractive index as a function of exposure time was not monotonic. This evolution can be explained by the assumption that some electric-field-induced diffusion of electron trapped centers [Ge(1) and Ge(2)] from the fiber core is involved.
Collapse
|
14
|
Nishii J, Yamanaka H. Bragg gratings printed upon thin glass films by excimer laser irradiation and selective chemical etching. APPLIED OPTICS 1997; 36:6852-6856. [PMID: 18259555 DOI: 10.1364/ao.36.006852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Photon-induced property changes of sputter-deposited GeO(2)-SiO(2) thin glass films were investigated. Irradiation with ArF laser pulses induced the changes in refractive index of -10% and volume of +30% in the film without ablation. A Bragg grating with a positive sinusoid wave pattern was printed upon the film by irradiation with ArF excimer laser pulses through a phase mask. The irradiated area could be quickly etched by a HF solution. The ratio of etching rate of irradiated area to unirradiated area was higher than 30. A Bragg grating with a surface relief pattern was successfully formed on the film by irradiation with excimer laser pulses followed by chemical etching. Diffraction efficiency of the gratings increased by 25 times with the etching.
Collapse
Affiliation(s)
- J Nishii
- Department of Optical Materials, Osaka National Research Institute, Agency of Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563, Japan
| | | |
Collapse
|
15
|
Nishii J, Yamanaka H, Hosono H, Kawazoe H. Preparation of Bragg gratings in sputter-deposited GeO(2)-SiO(2) glasses by excimer-laser irradiation. OPTICS LETTERS 1996; 21:1360-1362. [PMID: 19876352 DOI: 10.1364/ol.21.001360] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
GeO(2) - SiO(2) thin glass films were prepared by the rfsputtering deposition method. Changes in the refractive index of -3% and in the volume of +18% were induced in the film by irradiation with excimer-laser pulses. Bragg gratings a (periodic surface-relief pattern with a sinusoidal wave) have been written in the film by irradiation through a phase mask.
Collapse
|
16
|
Hosono H, Kawazoe H, Nishii J. Defect formation in SiO2:GeO2 glasses studied by irradiation with excimer laser light. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:R11921-R11923. [PMID: 9982887 DOI: 10.1103/physrevb.53.r11921] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
17
|
Fujimaki M, Yagi K, Ohki Y, Nishikawa H, Awazu K. Laser-power dependence of absorption changes in Ge-doped SiO2 glass induced by a KrF excimer laser. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:9859-9862. [PMID: 9982547 DOI: 10.1103/physrevb.53.9859] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|