The effect of room temperature ageing on the infra-red absorption spectra of thin-films of silicon oxide

Vacuum ◽  
1972 ◽  
Vol 22 (6) ◽  
pp. 233 ◽  
Author(s):  
P Timson ◽  
J Beynon
Keyword(s):  
Thin Films ◽  
Absorption Spectra ◽  
Room Temperature ◽  
Silicon Oxide ◽  
Infra Red ◽  
Temperature Ageing

Local Structure and Er3+ Emission from Pseudo-Amorphous GaN:Er Thin Films

1998 ◽  
Vol 536 ◽  
Author(s):  
S. B. Aldabergenova ◽  
M. Albrecht ◽  
A. A. Andreev ◽  
C. Inglefield ◽  
J. Viner ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Amorphous Matrix ◽  
Broad Band ◽  
Resonant Absorption ◽  
Absorption Bands ◽  
Host Matrix ◽  
Transmission Electron ◽  
Infra Red ◽  
Band Edge Luminescence

AbstractWe report on strong Er3+ luminescence in the visible and infra-red regions at room temperature in amorphous GaN:Er thin films prepared by DC magnetron co-sputtering. The intensity of the Er3+ luminescence at 1.535 μm corresponding to 4I13/2 → 4I15/2 transitions is greatly enhanced after annealing at 750°C. In this material GaN crystallites have formed and embedded in the continuous amorphous matrix. The crystallites are 4 to 7 nm in diameter as analyzed by high resolution transmission electron microscopy. The absorption edge, extending three orders of magnitude in absorption coefficient in the spectral range from 0.5 to 3.5 eV, is superimposed on resonant absorption bands of Er3+ ions.The total photoluminescence spectrum consists of welldefined Er3+ luminescence peaks imposed on a broad band edge luminescence from the amorphous GaN host matrix.

Light Emission from Intrinsic and Doped Silicon-Rich Silicon Oxide: from the Visible to 1.6 ΜM

1996 ◽  
Vol 452 ◽  
Author(s):  
L. Tsybeskov ◽  
K. L. Moore ◽  
P. M. Fauchet ◽  
D. G. Hall
Keyword(s):  
Rare Earth ◽  
External Quantum Efficiency ◽  
Room Temperature ◽  
Structural Modification ◽  
Silicon Oxide ◽  
Light Emission ◽  
Crystalline Silicon ◽  
Light Emitting ◽  
Infra Red ◽  
Doped Silicon

AbstractSilicon-rich silicon oxide (SRSO) films were prepared by thermal oxidation (700°C-950°C) of electrochemically etched crystalline silicon (c-Si). The annealing-oxidation conditions are responsible for the chemical and structural modification of SRSO as well as for the intrinsic light-emission in the visible and near infra-red spectral regions (2.0–1.8 eV, 1.6 eV and 1.1 eV). The extrinsic photoluminescence (PL) is produced by doping (via electroplating or ion implantation) with rare-earth (R-E) ions (Nd at 1.06 μm, Er at 1.5 μm) and chalcogens (S at ∼1.6 μm). The impurities can be localized within the Si grains (S), in the SiO matrix (Nd, Er) or at the Si-SiO interface (Er). The Er-related PL in SRSO was studied in detail: the maximum PL external quantum efficiency (EQE) of 0.01–0.1% was found in samples annealed at 900°C in diluted oxygen (∼ 10% in N2). The integrated PL temperature dependence is weak from 12K to 300K. Light emitting diodes (LEDs) with an active layer made of an intrinsic and doped SRSO are manufactured and studied: room temperature electroluminescence (EL) from the visible to 1.6 μmhas been demonstrated.

High-density plasma silicon oxide thin films grown at room-temperature

2008 ◽  
Vol 85 (5-6) ◽  
pp. 1245-1247
Author(s):  
M.E. Vlachopoulou ◽  
P. Dimitrakis ◽  
A. Tserepi ◽  
V.Em. Vamvakas ◽  
S. Koliopoulou ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Silicon Oxide ◽  
High Density ◽  
Oxide Thin Films ◽  
Density Plasma

Strain and temperature dependent absorption spectra studies for identifying the phase structure and band gap of EuTiO3 perovskite films

2015 ◽  
Vol 17 (47) ◽  
pp. 31618-31623 ◽  
Author(s):  
Kai Jiang ◽  
Run Zhao ◽  
Peng Zhang ◽  
Qinglin Deng ◽  
Jinzhong Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Absorption Spectra ◽  
Phase Structure ◽  
Room Temperature ◽  
Interband Transitions ◽  
Temperature Dependent ◽  
Dependent Absorption ◽  
Xrd Patterns ◽  
Schematic Diagrams

(a) The XRD patterns of ETO thin films measured at room temperature. (b) Schematic diagrams of the photo-induced interband transitions.

Changes in Structure and Composition of Silicon Oxide Thin Films Induced by Ultraviolet Illumination

1996 ◽  
Vol 441 ◽  
Author(s):  
E. G. Parada ◽  
P. González ◽  
B. León ◽  
M. Pérez-Amor ◽  
M. F. DA Silva ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Silicon Oxide ◽  
Oxide Films ◽  
Hydroxyl Groups ◽  
Elastic Recoil ◽  
Oxide Thin Films ◽  
Tetrahedral Configuration ◽  
Illumination Time ◽  
Uv Illumination

AbstractThe transformation of silicon oxide thin films at room-temperature by UV-photons provided by a Xe2* incoherent excimer lamp (λ = 172 nm, Δλ = 14 nm) was studied. Films were produced at low-temperature (T = 260 °C) by ArF laser-induced CVD (LCVD) in parallel configuration from a silane/nitrous oxide/argon gas mixture. The silicon oxide films were irradiated in several consecutive steps to follow-up the modifications with the illumination time. Rutherford backscattering (RBS), infrared (IR) and X-ray photoelectron (XPS) spectroscopies, ellipsometry, and elastic recoil detection analysis (ERDA) were used to characterize the effects of the irradiation on the structure, composition, density, and hydrogen content.Under the UV illumination the as-deposited film evolves from a suboxide film (SiO1.6) to a stoichiometric silicon dioxide (SiO2), and its originally strained structure changes towards a relaxed tetrahedral configuration. The UV irradiation is able to anneal at room temperature the silicon oxide films breaking the Si-H bonds and incorporating new SiO and hydroxyl groups in a relaxed network. The hydrogen does not effuse out, but remains in the film as molecular hydrogen and/or forming silanol or water groups.

Thin Films Stress Aging Study using Micromachined Cantilevers

2004 ◽  
Vol 854 ◽  
Author(s):  
Christophe Malhaire ◽  
Alexandru Andrei ◽  
Sebastiano Brida ◽  
Daniel Barbier
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Silicon Oxide ◽  
Harsh Environment ◽  
Determination Method ◽  
Stress Determination ◽  
3D Finite Element ◽  
Aging Study ◽  
C 30

ABSTRACTThe purpose of the present work was to study the long term stress stability of thin films used in harsh environment sensors. A stress determination method, based on cantilevers curvatures measurements, checked by means of 3D finite element simulations, has been proposed. Stress measurements for dielectric (silicon oxide and nitride) and metallic (AlTi and TiW) thin films have been periodically performed at room temperature, after standard annealing (450°C / 30 min in a N2+H2 atmosphere) and after 4 weeks thermal aging at 150°C or 200°C.

The ageing of sesquioxide gels. II. Alumina gels

1962 ◽  
Vol 33 (257) ◽  
pp. 145-157 ◽  
Author(s):  
R. C. Mackenzie ◽  
R. Meldau ◽  
J. A. Gard
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Aluminium Chloride ◽  
X Ray ◽  
High Ph ◽  
Ph Values ◽  
Gel Particles ◽  
Infra Red ◽  
Alumina Gels ◽  
Temperature Ageing

SummaryAluminium oxides occur widely in soils and are of considerable pedological significance. The ageing of alumina gels, prepared from aluminium chloride and ammonia, into crystalline hydroxides has been investigated using thermal, X-ray, infra-red, and electron-microscope techniques. At room temperature ageing is more rapid at high pH values. The structure of the original gel particles appears to resemble boehmite and ageing causes the formation of bayerite with small amounts of gibbsite. The morphology of the various mineral types is considered and a mechanism of ageing suggested.

Optoelectronic and Structural Properties of Plasma Deposited Nanocrystalline Hydrogenated Silicon Oxide Thin Films

NANO ◽  
2021 ◽  
pp. 2150115
Author(s):  
Tapati Jana ◽  
Romyani Goswami
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Structural Properties ◽  
Oxygen Content ◽  
Gas Flow ◽  
Room Temperature ◽  
Silicon Oxide ◽  
Quantum Confinement Effect ◽  
Hydrogen Gas ◽  
Hydrogenated Silicon

To develop wide bandgap materials for solar cells and other optoelectronic devices, undoped hydrogenated silicon oxide (SiOx:H) thin films are prepared by conventional radio frequency plasma enhanced chemical vapor deposition (RF PECVD) method. The variation of carbon dioxide dilution ([Formula: see text]) on optoelectronic and structural properties are studied thoroughly by keeping silane and hydrogen gas flow fixed. Surface morphology of the SiOx:H films have been studied by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). Distinct silicon nanocrystallites of average diameter [Formula: see text] 3–6[Formula: see text]nm embedded uniformly in amorphous SiOx network have been observed in high resolution Transmission Electron Microscopy (HRTEM). From Fourier Transform Infrared spectra (FTIR), it is observed that oxygen content ([Formula: see text]) increases initially with [Formula: see text] and afterwards it decreases. Strong room temperature photoluminescence (PL) peak is obtained for the as-deposited films having lower oxygen content ([Formula: see text]). The origin of room temperature PL spectra and its correlation with [Formula: see text] can be explained by quantum confinement effect (QCE) theory.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

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