scholarly journals Native defect-assisted enhanced response to CH4 near room temperature by Al0.07Ga0.93N nanowires

2018 ◽  
Vol 20 (27) ◽  
pp. 18391-18399 ◽  
Author(s):  
Santanu Parida ◽  
A. Das ◽  
Arun K. Prasad ◽  
Jay Ghatak ◽  
Sandip Dhara
Keyword(s):  
Room Temperature ◽  
Native Defect ◽  
Native Defects

Enhanced CH4 sensing with sufficient sensitivity of 100 ppm at 50 °C is realized for Al0.07Ga0.93N nanowires by utilizing native defects.

Correlation between Room Temperature Photoluminescence and Resistivity in Semiinsulating Silicon Carbide

2006 ◽  
Vol 527-529 ◽  
pp. 717-720 ◽  
Author(s):  
Sashi Kumar Chanda ◽  
Yaroslav Koshka ◽  
Murugesu Yoganathan
Keyword(s):  
Low Temperature ◽  
Point Defects ◽  
Room Temperature ◽  
Vanadium Content ◽  
Mapping Technique ◽  
Native Defect ◽  
Room Temperature Photoluminescence ◽  
Native Point Defects ◽  
Pl Mapping ◽  
Resistivity Variation

A room temperature PL mapping technique was applied to establish the origin of resistivity variation in PVT-grown 6H SiC substrates. A direct correlation between the native defect-related PL and resistivity was found in undoped (V-free) samples. In vanadium-doped samples with low vanadium content, the resistivity showed a good correlation with the total PL signal consisting of contributions from both vanadium and native point defects. Well-known UD1 and UD3 levels were revealed by low-temperature PL spectroscopy. Some correlation was observed between these low-temperature PL signatures and the resistivity distribution.

Unveiling the interplay between induced native defects and room temperature magnetic ordering in titanium deficient disordered-TiO2 nanoparticles

2020 ◽  
Vol 32 (9) ◽  
pp. 095701
Author(s):  
Jayaseelan Dhakshinamoorthy ◽  
Sachin Kumar Srivastava ◽  
Durgamadhab Mishra ◽  
Biji Pullithadathil
Keyword(s):  
Tio2 Nanoparticles ◽  
Room Temperature ◽  
Magnetic Ordering ◽  
Native Defects

Evidence for Different Kinds of Dangling Bond Defects in a-Si:H

1993 ◽  
Vol 297 ◽  
Author(s):  
Minh Tran ◽  
H. Fritzsche ◽  
P. Stradins
Keyword(s):  
Defect Concentration ◽  
Electron Lifetime ◽  
Native Defect ◽  
Dangling Bond ◽  
Native Defects

Comparing the photoconductivity σp of undoped samples with different native defect concentrations we find that light-induced metastable defects decrease the electron lifetime more strongly than the native defects. We discuss the differences between native and metastable dangling bond defects. We find that the constant photocurrent method underestimates the defect concentration in undoped a-Si:H.

scholarly journals Native Umbilical Defect for Laparoscopic Entry

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
Tarek Osama Hegazy ◽  
Mohamed Hassan Ali ◽  
Ahmed Amr Mohsen ◽  
Mahmoud Azhary ◽  
Ahmad Yahia Abdel Dayem
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Native Defect ◽  
Open Technique ◽  
Entry Site ◽  
Native Defects ◽  
Umbilical Incision ◽  
Trocar Insertion ◽  
Laparoscopic Entry ◽  
Direct Trocar Insertion

Background: The presence of defects in native umbilical in adults and its use as laparoscopic first entry site is poorly documented. It would likely be a safer method than the Veress needle and direct trocar insertion. This work aimed to report the prevalence and size of native umbilical defects, and their relationship with gender, age and body mass index. Methods: In 160 consecutive laparoscopic operations, a trans-umbilical incision was made and a defect at its base was looked for. When found, the defect was measured and used as the first port entry site. Relationships of presence of native defects and their sizes in relation to gender, age and BMI were analyzed. Results: The prevalence of a native defect in this series was 90%. Its presence had no relation with gender, age or BMI. Its size, however, positively correlated with age and BMI. No complications were related to the defect’s use for first laparoscopic entry site. Conclusion: A native umbilical defect is present in 90% of adults. Whenever present, it is recommended for use as the first port entry site by an open technique. This method is simple and safe and avoids unnecessarily inducing another defect. Keywords: Laparoscopy, Open technique, Access, Native defect, Umbilical defect

On the Origin of the New Electron Traps Induced By Rapid Thermal Annealing in GaAs Using Capping Proximity Technique.

1988 ◽  
Vol 144 ◽  
Author(s):  
G. Marrakchi ◽  
G. Chaussemy ◽  
A. Laugier ◽  
G. Guillot.
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Native Defect ◽  
Physical Origin ◽  
Electron Traps ◽  
Native Defects ◽  
Growth Method ◽  
Transient Spectroscopy

ABSTRACTRapid Thermal Annealing (RTA) effects on generation or annihilation of deep levels in GaAs have been investigated by Deep Level Transient Spectroscopy (DLTS). Capping proximity technique using three annealing configurations are employed to anneal Liquid Encapsulated Czochralski (LEC) and Bridgman (B) substrates, or Vapor Phase Epitaxy (VPE) and Liquid Phase Epitaxy (LPE) layers. The RTA treatment is performed from 800 to 950°C for two annealing times ( 3 and 10s).The DLTS data show that the evolution of the native defects depends on the GaAs growth method and also the annealing configuration. We observe the appearance of two new electron traps named RL1 and RL2 induced by the RTA process which depend on the kind of substrate: RL1 and RL2 are created in LEC material while only RL1 is detected in B material. A general comparison of our results with others reported in the literature show that these new electron traps are related to the change of stoichiometry at the GaAs surface and also depend on the existence of specific native defects in the starting GaAs material. It is proposed that the creation of RL1 is related to the EL6 native defect and discuss a possible physical origin for this level. We also propose that RL2 and EL5 originate from the same defect and suggest the divacancy VGaVAs as a possible origin for this trap.

Optical Characterization of Mg- and Si-Implanted GaN

2001 ◽  
Vol 680 ◽  
Author(s):  
James A. Fellows ◽  
Yung Kee Yeo ◽  
Robert L. Hengehold ◽  
Leonid Krasnobaev
Keyword(s):  
Room Temperature ◽  
Deep Acceptor ◽  
Native Defects ◽  
Implantation Temperature ◽  
Luminescence Peak ◽  
Activation Efficiency ◽  
Deep Donor ◽  
Hall Effect Measurements ◽  
Anneal Temperature

ABSTRACTThe optical and electrical properties of Mg- and Si-implanted GaN were investigated using photoluminescence, cathodoluminescence, and Hall-effect measurements. Implantation of Mg, Si, Mg+Si, Mg+O, Mg+C, and Mg+P was made into undoped semi-insulating MBE-grown GaN at energies from 125 to 260 keV at room temperature and 800 oC with doses of 1x1014 to 5x1015 cm−2. The samples were capped with AlN and annealed at temperatures ranging from 1100 to 1300 oC for 9 s to 20 min. The dominant luminescence peak in all Mg-implanted and annealed GaN is a broad green luminescence (GL) band at 2.36 eV, which may be related to a deep donor-deep acceptor complex transition resulting from the Mg implant, residual implant damage, and/or native defects. The relative intensities of this GL band and secondary peaks from 2.75-3.28 eV vary as a function of implantation temperature, ion dose, species, and anneal temperature. All Mg single and dual implantation resulted in extremely resistive GaN layers, except Mg+Si, which resulted in weakly n-type GaN. However, the Si-implanted GaN produced an electrical activation efficiency as high as 73% after annealing at 1200 oC for 5 min.

Defects and Optoelectronic Properties in 2D Semiconductors

2020 ◽  
Vol 29 (9) ◽  
pp. 11-14
Author(s):  
Hyun Seok LEE
Keyword(s):  
Room Temperature ◽  
Van Der Waals ◽  
Atomic Layer ◽  
Optoelectronic Properties ◽  
Coulomb Interactions ◽  
Native Defects ◽  
2D Semiconductors ◽  
Low Dimensionality ◽  
Excitonic Emission ◽  
Optoelectronic Applications

Two-dimensional (2D) van der Waals semiconductors have potential for various optoelectronic applications, owing to their unique optical and electrical properties at an atomic layer thickness. A stable excitonic emission from 2D monolayer semiconductors at room temperature, owing to a reduced dielectric screening effect, opens new fields of research on excitonics and valleytronics. Moreover, their low dimensionality without surface dangling bonds allows for unique quantum transport phenomena via artificial van der Waals stacking using a versatile library of 2D materials. In this article, the author introduces the tunable quantum optoelectronic properties of 2D semiconductors by manipulating native defects, van der Waals interfaces, Coulomb interactions, etc. Additionally, the author reviews the electronic and the optoelectronic applications utilizing such unique tunable properties of 2D semiconductors.

NATIVE DEFECT COMPENSATION IN III-ANTIMONIDE BULK SUBSTRATES

2004 ◽  
Vol 14 (03) ◽  
pp. 658-663 ◽  
Author(s):  
ROBINSON PINO ◽  
YOUNGOK KO ◽  
PARTHA S. DUTTA
Keyword(s):  
Low Temperature ◽  
Carrier Concentration ◽  
Carrier Density ◽  
Native Defect ◽  
High Concentration ◽  
Temperature Growth ◽  
Native Defects ◽  
Low Temperature Growth ◽  
Order Of Magnitude ◽  
Impurity Doping

As-grown, undoped III-antimonide bulk substrates contain high concentration of native defects resulting in high residual carrier density. In this paper, we have demonstrated that native defects can be compensated in bulk substrates of GaSb , InSb , and Ga 1-x In x Sb via impurity doping and low temperature growth from nonstoichiometric melts and solutions. Decrease in residual carrier concentration up to one order of magnitude at 300 K and three orders of magnitude at 77 K have been achieved.

Theoretical Investigation of Nitrogen-Doping Effect on Native Defect Aggregation Processes in Silicon

2002 ◽  
Vol 719 ◽  
Author(s):  
H. Kageshima ◽  
A. Taguchi ◽  
K. Wada
Keyword(s):  
Total Energy ◽  
First Principles ◽  
Nitrogen Doping ◽  
Doping Effect ◽  
Native Defect ◽  
First Principles Calculations ◽  
Native Defects ◽  
Aggregation Processes ◽  
Defect Aggregation ◽  
Shed Light

AbstractWe theoretically investigated interactions between nitrogen (N) atoms and Si native defects, vacancy (V) and interstitial (I), by using first-principles calculations in order to shed light on the nitrogen-doping effect on the defect aggregation processes. Stabilities of various N-I and N-V complexes are examined by calculating the total energy. We found that N atoms form stable complexes with both of V and I. The formation of such stable complexes reduces the effective concentrations of the native defects, resulting in the suppression of aggregation processes of V and I.

Role of Native Defect in Near Room Temperature CH4 Sensing Using Nanostructured V2O5

2020 ◽  
Vol 20 (9) ◽  
pp. 4555-4561
Author(s):  
Reshma P. Radhakrishnan ◽  
Arun K. Prasad ◽  
Sandip Dhara
Keyword(s):  
Room Temperature ◽  
Native Defect
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