Deep Levels in Oxygenated n-Type High-Resistivity FZ Silicon before and after a Low-Temperature Hydrogenation Step

2003 ◽  
Vol 150 (9) ◽  
pp. G520 ◽  
Author(s):  
E. Simoen ◽  
C. Claeys ◽  
R. Job ◽  
A. G. Ulyashin ◽  
W. R. Fahrner ◽  
...  
Keyword(s):  
Low Temperature ◽  
Deep Levels ◽  
High Resistivity ◽  
Before And After

The Effect of Annealing on High-resistivity and Semi-insulating 4H-SiC

2002 ◽  
Vol 742 ◽  
Author(s):  
S. R. Smith ◽  
A. O. Evwaraye ◽  
W. C. Mitchel
Keyword(s):  
Transition Metal ◽  
Thermal Oxidation ◽  
Thermal Annealing ◽  
Deep Levels ◽  
High Resistivity ◽  
Admittance Spectroscopy ◽  
Metal Impurities ◽  
Transition Metal Impurities ◽  
Before And After

ABSTRACTWe have examined specimens of high-resistivity, and semi-insulating, 4H-SiC before and after thermal annealing at 1600 °C, using Optical Admittance Spectroscopy. We have found enhanced ultraviolet response in most specimens. Enhanced activation of previously undetected V impurities has also been observed. Peaks believed to be attributable to complex V-related defects were greatly reduced by annealing. The annealing was in addition to a thermal oxidation at 1150 °C for 4 hours. The purpose of the oxidation was to remove surface-related deep levels known to be present in polished SiC. Transition metal impurities in these bulk specimens were quantified by SIMS. In specimens where Ti was not detected by SIMS, no further activation of Ti centers was detected by Optical Admittance Spectroscopy.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

Enhancement of low temperature thermopower in high-resistivity films

1988 ◽  
Vol 66 (10) ◽  
pp. 1023-1026 ◽  
Author(s):  
A. Mawdsley ◽  
A.B. Kaiser
Keyword(s):  
Low Temperature ◽  
High Resistivity

Environmental Influence on the Tolerance of Corn to Atrazine

Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Lafayette Thompson ◽  
F. W. Slife ◽  
H. S. Butler
Keyword(s):  
Zea Mays ◽  
High Temperature ◽  
Low Temperature ◽  
Light Intensity ◽  
Environmental Influence ◽  
High Light Intensity ◽  
High Light ◽  
Growth Chamber ◽  
Peptide Conjugates ◽  
Before And After

Corn(Zea maysL.) in the two to three-leaf stage grown 18 to 21 days in a growth chamber under cold, wet conditions was injured by postemergence application of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) plus emulsifiable phytobland oil. Injury was most severe when these plants were kept under cold, wet conditions for 48 hr after the herbicidal spray was applied, followed by exposure to high light intensity and high temperature. Under these growth chamber conditions, approximately 50% of the atrazine-treated plants died. Since wet foliage before and after application increased foliar penetration and low temperature decreased the rate of detoxication to peptide conjugates, atrazine accumulated under cold, wet conditions. This accumulation of foliarly-absorbed atrazine and the “weakened” conditions of the plants grown under the stress conditions is believed to be responsible for the injury to corn. Hydroxylation and the dihydroxybenzoxazin-3-one content in the roots were reduced at low temperature, but it is unlikely that this contributed to the death of the corn.

Investigation of the properties of knitted woolen fabrics treated with oxygen low-temperature plasma for sportswear applications

2021 ◽  
pp. 004051752110306
Author(s):  
Honglian Cong ◽  
Boyu Zhao ◽  
Hao Han ◽  
Xuliang Yu
Keyword(s):  
Low Temperature ◽  
Plasma Treatment ◽  
Moisture Absorption ◽  
Mapping Method ◽  
Function Evaluation ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Wool Fibers ◽  
Before And After ◽  
Concentration Mapping

Nine groups of knitted woolen fabrics for sportswear with different technical characteristics were treated with oxygen low-temperature plasma, and the changes in the surface morphology and chemical composition of wool fibers before and after plasma treatment, as well as the changes in the applicability indexes of knitted woolen fabrics, were studied. Finally, the comfort performance of the fabrics was evaluated by combining the concentration mapping method and the function evaluation value method. The analysis found that the surface scales of wool fibers were seriously etched after oxygen low-temperature plasma treatment, and the anti-felting, bursting strength and moisture absorption of the knitted woolen fabrics were improved. At the same time, the quick-drying index of the fabric has also been improved to a certain extent. This research provides a basis for the development of knitted woolen fabric for sportswear with excellent performance.

Deep levels in high resistivity GaN epilayers grown by MOCVD

2006 ◽  
Vol 3 (3) ◽  
pp. 585-588 ◽  
Author(s):  
Cebao Fang ◽  
Xiaoliang Wang ◽  
Junxi Wang ◽  
Chao Liu ◽  
Cuimei Wang ◽  
...  
Keyword(s):  
Deep Levels ◽  
High Resistivity

Deep Level Centers in Carbon-Doped High Resistivity GaN

2014 ◽  
Vol 997 ◽  
pp. 492-495
Author(s):  
Huan Cui ◽  
Li Wu Lu ◽  
Ling Sang ◽  
Bai He Chen ◽  
Zhi Wei He ◽  
...  
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Deep Levels ◽  
Hall Measurement ◽  
High Resistivity ◽  
Organic Chemical ◽  
Carbon Doped ◽  
Metal Organic ◽  
High Level ◽  
Organic Chemical Vapor Deposition

The deep levels of carbon doped high resistivity (HR) GaN samples grown by metal-organic chemical vapor deposition (MOCVD) has been investigated using thermally stimulated current (TSC) spectroscopy and high temperature (HT) Hall measurement. Two different thickness of 100 and 300 nm were used to be compared. It was found that four distinct deep levels by TSC and one deep level by HT Hall measurement were observed in both samples, which means great help for the decrease of leakage current and lifetime limitations of device utilizing the structure. The activation energy of these levels was calculated and their possible origins were also proposed. The low temperature traps, might be related to VN, 0.50 and 0.52eV related to incorporate a high level carbon, 0.57eV related to VGa, 0.59eV related to CGaor NGa, 0.91 and 0.97eV related to interstitial N1.

Low-Temperature Diffusion of Transition Metals at the Presence of Radiation Defects in Silicon

2011 ◽  
Vol 178-179 ◽  
pp. 421-426
Author(s):  
Jan Vobecký ◽  
Volodymyr Komarnitskyy ◽  
Vít Záhlava ◽  
Pavel Hazdra
Keyword(s):  
Low Temperature ◽  
Active Sites ◽  
Carrier Lifetime ◽  
High Energy ◽  
Deep Levels ◽  
Radiation Defects ◽  
Metal Atoms ◽  
Temperature Diffusion ◽  
Concentration Enhancement ◽  
Application Potential

Low-temperature diffusion of Cr, Mo, Ni, Pd, Pt, and V in silicon diodes is compared in the range 450 - 800 oC. Before the diffusion, the diodes were implanted with high-energy He2+ to assess, if the radiation defects enhance the concentration of metal atoms at electrically active sites and what is the application potential for carrier lifetime control. The devices were characterized using AES, XPS, DLTS, OCVD carrier lifetime and diode electrical parameters. The metal atoms are divided into two groups. The Pt, Pd and V form deep levels in increased extent at the presence of radiation defects above 600 oC, which reduces the excess carrier lifetime. It is shown as a special case that the co-diffusion of Ni and V from a NiV surface layer results fully in the concentration enhancement of the V atoms. The enhancement of the acceptor level V-/0 (EC 0.203 eV) and donor level V0/+ (EC 0.442 eV) resembles the behavior of substitutional Pts. The second group is represented by the Mo and Cr. They easily form oxides, which can make their diffusion into a bulk more difficult or impossible. Only a slight enhancement of the Cr-related deep levels by the radiation defects has been found above 700 oC.

scholarly journals COMPOSITION, STRUCTURE AND TEXTURAL CHARACTERISTICS OF DOMESTIC ACID ACTIVATED BENTONITE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Zоrаn Pеtrоvić ◽  
Pеrо Dugić ◽  
Vојislаv Аlеksić ◽  
Sаbinа Bеgić ◽  
Vlаdаn Мićić ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Low Temperature ◽  
Layered Structure ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Textural Characteristics ◽  
X Ray ◽  
Before And After ◽  
Activated Bentonite ◽  
Composition Structure

Bentonites are aluminosilicate minerals which, due to their porosity, layered structure and composition have a wide application. Structural and textural characteristics of bentonite may be improved by different modification procedures. The aim of this study was to investigate compositional, structural and textural characteristics of domestic bentonite in place Gerzovo, before and after the activation with sulfuric acid. These characteristics were investigated by analytical methods, X-ray diffraction (XRD) and the method of low-temperature nitrogen adsorption (BET). Characteristics of acid-activated bentonite were compared with the characteristics of commercial active clay. The obtained results showed that the activation of bentonite with sulfuric acid leads to a significant improvement in structural and textural characteristics. Using these results it can be assumed that this bentonite will have good adsorption characteristics and can serve as an alternative in comparison with imported commercial aluminosilicate-based adsorbents.

Sign in / Sign up

Export Citation Format

Share Document