scholarly journals Prism coupling as a non destructive tool for optical characterization of (Al,Ga) nitride compounds

2000 ◽  
Vol 5 (S1) ◽  
pp. 747-753
Author(s):  
E. Dogheche ◽  
B. Belgacem ◽  
D. Remiens ◽  
P. Ruterana ◽  
F. Omnes
Keyword(s):  
Theoretical Approach ◽  
Optical Characterization ◽  
Structural Defects ◽  
Optical Data ◽  
Electronic Microscopy ◽  
Microscopy Analysis ◽  
Optical Behavior ◽  
Non Destructive ◽  
Good Agreement

An optical characterization technique is proposed for GaN based compounds deposited on sapphire. In AlGaN films grown by MOCVD, the film optical behavior and the substrate to layer interface are qualified from the measured optical data. The experimental and theoretical approach used for this purpose is described in detail. The results clearly show bending effects at the interface which may be related to structural defects; a good agreement with transmission electronic microscopy analysis is obtained.

Prism Coupling as a Non Destructive Tool for Optical Characterization of (Al,Ga) Nitride Compounds

1999 ◽  
Vol 595 ◽  
Author(s):  
E. Dogheche ◽  
B. Belgacem ◽  
D. Remiens ◽  
P. Ruterana ◽  
F. Omnes
Keyword(s):  
Theoretical Approach ◽  
Optical Characterization ◽  
Structural Defects ◽  
Optical Data ◽  
Electronic Microscopy ◽  
Microscopy Analysis ◽  
Optical Behavior ◽  
Non Destructive ◽  
Good Agreement

AbstractAn optical characterization technique is proposed for GaN based compounds deposited on sapphire. In AlGaN films grown by MOCVD, the film optical behavior and the substrate to layer interface are qualified from the measured optical data. The experimental and theoretical approach used for this purpose is described in detail. The results clearly show bending effects at the interface which may be related to structural defects; a good agreement with transmission electronic microscopy analysis is obtained.

Simulation and prediction of optical characterization of casting (Adamantan-Fulgide) thin films using (CTANNs) approach

2019 ◽  
Vol 33 (11) ◽  
pp. 1950093 ◽  
Author(s):  
A. M. A. EL-Barry ◽  
D. M. Habashy
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Back Propagation ◽  
Optical Characterization ◽  
Experimental Information ◽  
Training Algorithm ◽  
Energy Gaps ◽  
Resilient Back Propagation ◽  
Good Agreement

For reinforcement, the photochromic field and the cooperation between the theoretical and experimental branches of physics, the computational, theoretical artificial neural networks (CTANNs) and the resilient back propagation (R[Formula: see text]) training algorithm were used to model optical characterizations of casting (Admantan-Fulgide) thin films with different concentrations. The simulated values of ANN are in good agreement with the experimental data. The model was also used to predict values, which were not included in the training. The high precision of the model has been constructed. Moreover, the concentration dependence of both the energy gaps and Urbach’s tail were, also tested. The capability of the technique to simulate the experimental information with best accuracy and the foretelling of some concentrations which is not involved in the experimental data recommends it to dominate the modeling technique in casting (Admantan-Fulgide) thin films.

Non-destructive optical characterization of the surface region in bulk semiconductors and heterostructures

2000 ◽  
Vol 364 (1-2) ◽  
pp. 186-191 ◽  
Author(s):  
V Mizeikis ◽  
K Jarasiunas ◽  
N Lovergine ◽  
K Kuroda
Keyword(s):  
Surface Region ◽  
Optical Characterization ◽  
Bulk Semiconductors ◽  
Non Destructive

scholarly journals Optical Characterization of Porous Sputtered Silver Thin Films

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Olivier Carton ◽  
Jaouad Ghaymouni ◽  
Michaël Lejeune ◽  
Andreas Zeinert
Keyword(s):  
Optical Properties ◽  
Optical Characterization ◽  
Optical Data ◽  
Plasma Parameters ◽  
Silver Films ◽  
Physical Measurements ◽  
Silver Thin Films ◽  
Porous Silver ◽  
Effective Medium Models

The optical properties of various porous silver films, grown with a commercial DC sputter coater, were investigated and compared for different plasma parameters. Effective Drude models were successfully used for those films whose spectra did not show particular resonance peaks. For the other films, neither an effective Drude model nor effective medium models (Maxwell Garnett, Bruggeman, and Looyenga) can describe the optical properties. It turns out that a more general approach like the Bergman representation describes the optical data of these films accurately adopting porosity values consistent with physical measurements.

Optical characterization of ceramic thin films: Applications in low-temperature solid oxide fuel-cell materials research

2004 ◽  
Vol 19 (2) ◽  
pp. 573-578 ◽  
Author(s):  
B.P. Gorman ◽  
V. Petrovsky ◽  
H.U. Anderson ◽  
T. Petrovsky
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Optical Characterization ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell Materials ◽  
Reflection Spectrophotometry ◽  
Transmission And Reflection ◽  
Good Agreement

Characterization of thin film solid oxide fuel-cell materials can be difficult due to the range of porosities in electrodes and electrolytes as well as the nano-sized pores and particles. In this study, optical characterization techniques such as ultraviolet–visible transmission and reflection spectrophotometry are illustrated as methods for achieving information about the film density from the film refractive index as well as the film thickness. These techniques were used to investigate the sintering process of colloidal CeO2 on sapphire substrates and polymeric precursor-derived ZrO2:16%Y (YSZ) thin films on silicon over the temperature range 400–1000 °C, and the results were compared with traditional characterization techniques such as electron microscopy, profilometry, ellipsometry, and x-ray diffraction line broadening analyses. Most of the techniques were in good agreement with the CeO2 grain size changing from 5–65 nm and the film thickness changing from 0.8–0.5 μm. Comparisons of transmission and reflection spectrophotometry with ellipsometry illustrated that scattering effects from the porous CeO2 films caused an overestimation of the refractive index from ellipsometry, but allowed for accurate grain size measurements from transmission and reflection data. Both techniques were in good agreement during the sintering of the YSZ thin films, with the density changing from 90–100% theoretical after heating between 400 and 800 °C.

scholarly journals Optical Characterization of Zinc Modified Bismuth Silicate Glasses

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Rajesh Parmar ◽  
J. Hooda ◽  
R. S. Kundu ◽  
R. Punia ◽  
N. Kishore
Keyword(s):  
Band Gap ◽  
Optical Characterization ◽  
Dielectric Materials ◽  
Band Gap Energy ◽  
Glass System ◽  
Energy Band Gap ◽  
Classical Electron ◽  
Increase With Increase ◽  
Good Agreement

The optical characterization of glass samples in the system 40SiO2·xZnO · (60-x)Bi2O3withx=0, 5, 10, 15, 20, 25, 30, 35, and 40 prepared by conventional melt-quench technique has been carried out in the light of Hydrogenic Excitonic Model (HEM). The absorption coefficient spectra show good agreement with theoretical HEM for the present glass system and the values of different parameters likeEg,R,Γ1,Γc, andCohave been estimated from fitting of this model. The values of energy band gap estimated from fitting of HEM with experimental data are in good agreement with those obtained from Tauc’s plot for direct transitions. The band gap energy is found to increase with increase of ZnO content. The decrease in values of Urbach energy with increase in ZnO content indicates a decrease in defect concentration in the glass matrix on addition of ZnO content. Optical constantsnandkobeyk-kconsistency and the dielectric response of the studied glass system is similar to that obtained for Classical Electron Theory of Dielectric Materials. The calculated values of the metallization criterion (M) show that the synthesized glasses may be good candidates for new nonlinear optical materials.

scholarly journals Investigation of Metastable Low Dimensional Halometallates

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 280
Author(s):  
Navindra Keerthisinghe ◽  
Matthew S. Christian ◽  
Anna A. Berseneva ◽  
Gregory Morrison ◽  
Vladislav V. Klepov ◽  
...  
Keyword(s):  
Structure Determination ◽  
Solvothermal Synthesis ◽  
Structural Diversity ◽  
Optical Characterization ◽  
Optical Spectra ◽  
Structural Dimensionality ◽  
Low Dimensional ◽  
Optical Behavior ◽  
1D Chains

The solvothermal synthesis, structure determination and optical characterization of five new metastable halometallate compounds, [1,10-phenH][Pb3.5I8] (1), [1,10-phenH2][Pb5I12]·(H2O) (2), [1,10-phen][Pb2I4] (3), [1,10-phen]2[Pb5Br10] (4) and [1,10-phenH][SbI4]·(H2O) (5), are reported. The materials exhibit rich structural diversity and exhibit structural dimensionalities that include 1D chains, 2D sheets and 3D frameworks. The optical spectra of these materials are consistent with bandgaps ranging from 2.70 to 3.44 eV. We show that the optical behavior depends on the structural dimensionality of the reported materials, which are potential candidates for semiconductor applications.

On the Characterization of Ultra Thin Al Films Deposited onto SiC Substrate Using PIXE Technique

2011 ◽  
Vol 324 ◽  
pp. 302-305
Author(s):  
Ghassan Younes ◽  
Maher Soueidan ◽  
Gabriel Ferro ◽  
Khaled Zahraman ◽  
Bilal Nsouli
Keyword(s):  
Limit Of Detection ◽  
Ion Beam ◽  
Al Doping ◽  
X Ray ◽  
Tilting Angle ◽  
Silicon Carbide Substrate ◽  
Non Destructive ◽  
Accurate Quantification ◽  
Good Agreement

In this work the capability of the proton induced X-ray emission (PIXE) technique to monitor a rapid, non-destructive and accurate quantification of Al on or inside SiC is discussed. Optimization of PIXE acquisition parameters was performed using as reference, a thin Al film (2.5 nm) thermally evaporated onto silicon carbide substrate. In order to improve the sensitivity for Al detection and quantitative determination, a systematic study was undertaken using proton ion beam at different energies (from 0.2 to 3 MeV) with a different tilting angle (0°, 60°, and 80°). The limit of detection (LOD) was found to be lower than 0.02 nm. The optimum PIXE conditions (energy, angle) were applied for determining the Al doping concentration in thin (1 µm) 4H-SiC homoepitaxial layer. The Al concentration as determined by PIXE was found to be 3.9x1020 at/cm3 in good agreement with SIMS measurements, and the LOD was estimated to be 6x1018 at/cm3.

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