scholarly journals Thermoluminescence Response of AlN+Y2O3 Ceramics to Sunlight and X-Ray Irradiation

2021 ◽  
Vol 58 (1) ◽  
pp. 3-14
Author(s):  
J. Cipa ◽  
L. Trinkler ◽  
B. Berzina
Keyword(s):  
Emission Spectrum ◽  
Glow Curve ◽  
Uv Light ◽  
Emission Spectra ◽  
Wide Band ◽  
Practical Application ◽  
Irradiation Effects ◽  
Wide Band Gap ◽  
Sunlight Irradiation ◽  
X Ray

AbstractAlN is a wide band gap material with promising properties for dosimetric applications, especially in UV dosimetry. In the present research, the thermoluminescence method is used in order to better understand sunlight and X-ray irradiation effects on yttria doped AlN ceramics. In general, the TL response is characterised by a broad TL peak with maxima around 400–450 K and a TL emission spectrum with UV (400 nm), Blue (480 nm) and Red (600 nm) bands. Compared to the X-ray irradiation, sunlight irradiation creates a wider TL glow curve peak with a maximum shifted to higher temperatures by 50 K.Furthermore, in the TL emission spectra of AlN irradiated with sunlight the UV band is suppressed. The reasons of the TL peculiarities under two types of irradiation are discussed. Practical application of AlN ceramics as material for UV light TL dosimetry and, in particular, for sunlight dosimetry is estimated.

Theoretical and experimental investigation of point defects in cubic boron nitride

MRS Advances ◽  
2017 ◽  
Vol 2 (29) ◽  
pp. 1545-1550 ◽  
Author(s):  
Nicholas L. McDougall ◽  
Jim G. Partridge ◽  
Desmond W. M. Lau ◽  
Philipp Reineck ◽  
Brant C. Gibson ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Optical Emission ◽  
Wide Band ◽  
Wide Band Gap ◽  
Edge Structure ◽  
X Ray ◽  
Substitutional Defects ◽  
X Ray Absorption ◽  
Annealing Experiments

ABSTRACTCubic boron nitride (cBN) is a synthetic wide band gap material that has attracted attention due to its high thermal conductivity, optical transparency and optical emission. In this work, defects in cBN have been investigated using experimental and theoretical X-ray absorption near edge structure (XANES). Vacancy and O substitutional defects were considered, with O substituted at the N site (ON) to be the most energetically favorable. All defects produce unique signatures in either the B or N K-edges and can thus be identified using XANES. The calculations coupled with electron-irradiation / annealing experiments strongly suggest that ON is the dominant defect in irradiated cBN and remains after annealing. This defect is a likely source of optical emission in cBN.

Inorganic-Organic Hybrid Nanocomposites for Photovoltaic Applications

2012 ◽  
Vol 571 ◽  
pp. 120-124
Author(s):  
Liang Min Zhang
Keyword(s):  
Solar Cells ◽  
Uv Light ◽  
Solar Spectrum ◽  
Wide Band ◽  
Hybrid Nanocomposites ◽  
Wide Band Gap ◽  
Inorganic Semiconductors ◽  
The Cost ◽  
Ruthenium Dye ◽  
Photovoltaic Characteristics

Hybrid photovoltaic concepts based on a nanoscale combination of organic and inorganic semiconductors are promising way to enhance the cost efficiency of solar cells through a better use of the solar spectrum, a higher ratio of interface-to-volume, and the flexible processability of polymers. In this work, two types of thin film solar cells have been developed. In both types of solar cells, poly-N-vinylcarbazole (PVK) is used as electron donor, cadmium sulfide (CdS) and titanium dioxide (TiO2) nanocrystals are used as electron acceptors, respectively. Since TiO2 has a wide band gap and can only absorb UV light, in the second type of solar cell, ruthenium dye is used as photo-sensitizer. The preliminary results of photoconductive and photovoltaic characteristics of these two inorganic-organic composites are presented.

Epitaxial Growth of Aluminum Nitride on Sapphire and Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
J. Narayan ◽  
M. Razeghi
Keyword(s):  
Epitaxial Growth ◽  
Substrate Surface ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
High Quality ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTThe microstructural characteristics of wide band gap semiconductor, hexagonal A1N thin films on Si(100), (111), and sapphire (0001) and (10ī2) were studied by transmission electron microscopy (TEM) and x-ray diffraction. The films were grown by MOCVD from TMA1 + NH3 + N2 gas mixtures. Different degrees of film crystallinity were observed for films grown on α-A12O3 and Si substrates in different orientations. The epitaxial growth of high quality single crystalline A1N film on (0001) α-Al2O3 was demonstrated with a dislocation density of about 2*10 10cm−2 . The films on Si(111) and Si(100) substrates were textured with the c-axis of A1N being perpendicular to the substrate surface.

Stress origin and relaxation in epitaxial AlN thin films on SiC

2001 ◽  
Vol 696 ◽  
Author(s):  
Ravi Bathe ◽  
R.D. Vispute ◽  
Daniel Habersat ◽  
R. P. Sharma ◽  
T. Venkatesan ◽  
...  
Keyword(s):  
Thin Films ◽  
Rutherford Backscattering Spectrometry ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
X Ray ◽  
Force Microscopy ◽  
Ion Channeling ◽  
Atomic Force ◽  
Highly Strained

AbstractWe have investigated the epitaxy, surfaces, interfaces, and defects in AlN thin films grown on SiC by pulsed laser deposition. The stress origin, evolution, and relaxation in these films is reported. The crystalline structure and surface morphology of the epitaxially grown AlN thin films on SiC (0001) substrates have been studied using x-ray diffraction (θ–2θ, ω, and Ψ scans) and atomic force microscopy, respectively. The defect analysis has been carried out by using Rutherford backscattering spectrometry and ion channeling technique. The films were grown at various substrate temperatures ranging from room temperature to 1100 °C. X-ray diffraction measurements show highly oriented AlN films when grown at temperatures of 750- 800 °C, and single crystals above 800 °C. The films grown in the temperature range of 950 °C to 1000 °C have been found to be highly strained, whereas the films grown above 1000 °C were found to be cracked along the crystallographic axes. The results of stress as a function of growth temperature, thermal mismatch, growth mode, and buffer layer thickness will be presented, and the implications of these results for wide band gap power electronics will be discussed.

scholarly journals Formation of the X-ray line emission spectrum of excimer laser-produced plasmas

1998 ◽  
Vol 16 (1) ◽  
pp. 61-70 ◽  
Author(s):  
A. Magunov ◽  
A. Faenov ◽  
I. Skobelev ◽  
T. Pikuz ◽  
D. Batani ◽  
...  
Keyword(s):  
Experimental Data ◽  
Laser Radiation ◽  
Laser Pulse ◽  
Emission Spectrum ◽  
Pulse Train ◽  
Line Emission ◽  
Emission Spectra ◽  
Theoretical Modelling ◽  
Xecl Laser ◽  
X Ray

Time- and space-integrated emission spectra measurements have been performed in plasma produced by 308 nm wavelength XeCl laser radiation (IL = (4–10)·1012 W/cm2, τ = 10 ns) and by 248 nm wavelength KrF laser pulse train radiation (IL = 5·1015 W/cm2, τ = 7 ps, 16 pulses in train) on CF2 plane target. Theoretical modelling of Lyman series and He-like ion resonance series of fluorine and its fit of experimental data show considerable differences in the absorption of laser radiation in the two plasmas.

Some properties of amorphous hydrogenated silicon nitride prepared by ion-beam-assisted deposition

1991 ◽  
Vol 69 (5) ◽  
pp. 553-557 ◽  
Author(s):  
P. Wilson ◽  
D. C. Craigen ◽  
D. E. Brodie
Keyword(s):  
Uv Light ◽  
Ion Beam ◽  
Wide Band ◽  
Ion Source ◽  
Wide Band Gap ◽  
Hydrogenated Silicon ◽  
Hydrogen Mixture ◽  
Ion Beam Assisted Deposition ◽  
Amorphous Hydrogenated Silicon ◽  
Low Energy Ions

Thin films of a-SiNx:H were deposited using the ion-beam-assisted deposition technique. Silicon was evaporated from a resistively heated carbon crucible while the substrate was bombarded with low-energy ions (100 eV). The feed gas used for the ion source was primarily ammonia (NH3), but a 90% nitrogen, 10% hydrogen mixture was also tried. The nitrogen–hydrogen mixture resulted in nonhydrogenated films. Both the absence of absorption in the IR spectrum owing to oxygen, and the increase in slope of the Tauc plots are evidence of an improvement in film morphology owing to the ion bombardment. The wide band-gap films photoconduct when exposed to UV light. The photoconducting property is lost when the films are exposed to air, and is restored when the samples are thermally annealed in a vacuum.

Non-resonant X-ray/laser interaction spectroscopy as a method for assessing charge competition, trapping and luminescence efficiency in wide band-gap materials

2010 ◽  
Vol 130 (8) ◽  
pp. 1404-1414 ◽  
Author(s):  
N.R.J. Poolton ◽  
A.J.J. Bos ◽  
J. Wallinga ◽  
J.T.M. de Haas ◽  
P. Dorenbos ◽  
...  
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Laser Interaction ◽  
Wide Band Gap ◽  
X Ray ◽  
Luminescence Efficiency

Nanostructure Assembly of Indium Sulphide Quantum Dots and Their Characterization

2008 ◽  
Vol 8 (2) ◽  
pp. 689-694 ◽  
Author(s):  
B. Vigneashwari ◽  
V. Ravichandran ◽  
P. Parameswaran ◽  
S. Dash ◽  
A. K. Tyagi
Keyword(s):  
Quantum Dots ◽  
Colloidal Suspension ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Wide Band Gap ◽  
X Ray ◽  
Glass Substrates ◽  
Series Of Experiments ◽  
Indium Sulphide

Nanocrystals (∼5 nm) of the semiconducting wide band gap material β-In2S3 obtained by chemical synthesis through a hydrothermal route were characterized for phase and compositional purity. These nanoparticles exhibited quantum confinement characteristics as revealed by a blue-shifted optical absorption. These quantum dots of β-In2S3 were electrically driven from a monodisperse colloidal suspension on to conducting glass substrates by Electophoretic Deposition (EPD) technique and nanostructural thin films were obtained. The crystalline and morphological structures of these deposits were investigated by X-ray diffraction and nanoscopic techniques. We report here that certain interesting nanostructural morphologies were observed in the two-dimensional quantum dot assemblies of β-In2S3. The effect of the controlling parameters on the cluster growth and deposit integrity was also systematically studied through a series of experiments and the results are reported here.

scholarly journals Emission Spectra of LSO and LYSO Crystals Excited by UV Light, X-Ray and $\gamma$-ray

2008 ◽  
Vol 55 (3) ◽  
pp. 1759-1766 ◽  
Author(s):  
Rihua Mao ◽  
Liyuan Zhang ◽  
Ren-Yuan Zhu
Keyword(s):  
Gamma Ray ◽  
Uv Light ◽  
Emission Spectra ◽  
X Ray
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