Hydrogen Passivation and Reactivation of DX Centers in Se-Doped and Si-Doped AlGaAs - - A Comparison

1992 ◽  
Vol 262 ◽  
Author(s):  
G. Roos ◽  
N. M. Johnsons ◽  
C. Herring ◽  
J. S. Harris
Keyword(s):  
Space Charge ◽  
Schottky Diodes ◽  
Thermal Dissociation ◽  
Group Iv ◽  
Hydrogen Passivation ◽  
Group Vi ◽  
Dx Centers ◽  
Charge Layer ◽  
Dissociation Energies ◽  
Si Doped

ABSTRACTThe effect of hydrogenation on DX centers was evaluated for both Si- and Se-doped AlxGa1-xAs (x=0.26 and 0.23). MBE-grown AIGaAs:Si and MOCVD-grown AIGaAs:Se epilayers were hydrogenated with either monatomic hydrogen or deuterium from a remote plasma at 250°C for 1h. The passivation and subsequent reactivation kinetics were studied with C-V and DLTS techniques. Reactivation was investigated in the space-charge layer of Schottky diodes under different bias conditions. While the Group VI and Group IV deep donors respond similarly to passivation, they display significantly different reactivation kinetics, with thermal dissociation energies of 1.5 eV and 1.2 eV for Se-H and Si-H, respectively. These values are close to the energies previously determined for reactivation of the Si and Se shallow donors in both AIGaAs and GaAs. Therefore, they are not significantly dependent on the Al concentration (x < 0.30) even for donors residing on the As sublattice. Our results are consistent with the Chang-Chadi model of DX centers.

Effect of the electric field in the space-charge layer on the efficiency of short-wave photoelectric conversion in GaAs Schottky diodes

1997 ◽  
Vol 31 (10) ◽  
pp. 1053-1056 ◽  
Author(s):  
T. V. Blank ◽  
Yu. A. Gol’dberg ◽  
O. V. Konstantinov ◽  
O. I. Obolenskii ◽  
E. A. Posse
Keyword(s):  
Electric Field ◽  
Space Charge ◽  
Schottky Diodes ◽  
Short Wave ◽  
Space Charge Layer ◽  
Photoelectric Conversion ◽  
Charge Layer

Donor Reactivation Kinetics and Hydrogen Redistribution in the Space Charge Layer of N-Type Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
Y. -A. Wu ◽  
G. Roos ◽  
N. M. Johnson ◽  
C. Herring
Keyword(s):  
Activation Energy ◽  
Space Charge ◽  
Charge State ◽  
Negative Charge ◽  
Schottky Diodes ◽  
Space Charge Layer ◽  
Time Constants ◽  
Previous Conclusion ◽  
Charge Layer ◽  
Kinetics Of

ABSTRACTThe passivation and reactivation of As donor dopants in n-type Si was studied with both monatomic hydrogen and deuterium. Hydrogenated Schottky diodes were characterized with C-V and DLTS measurements. The reactivation kinetics of the As-H and As-D complexes were studied in the space-charge layer of reverse biased diodes in the temperature range from 60°C to 120°C. These bias-anneals yield dissociation time constants for As-H, from which an averaged activation energy of 1.17±0.1 eV was determined. Although the dissociation of the As-H complex is appreciably slower than that previously measured for P-H, the activation energy is within about 0.05 eV of that determined previously for the P-H complex (1.2 eV). The depth redistribution of the As-H complexes after bias-annealing agrees with the previous conclusion that hydrogen can assume a negative charge state in n-type Si.

Evaluation of efficacy of Aloe vera (L.) Burm. f. gel solution in methylcellulose-induced ocular hypertension in New Zealand white rabbits

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jhanvi J. Vaghela ◽  
Manish J. Barvaliya ◽  
Sugnesh J. Parmar ◽  
Chandrabhanu R. Tripathi
Keyword(s):  
Disease Control ◽  
Ocular Hypertension ◽  
Aloe Vera ◽  
Group Iv ◽  
Control Group ◽  
Group Vi ◽  
Concurrent Treatment ◽  
Maximum Reduction ◽  
New Zealand White Rabbits ◽  
Time Point

AbstractObjectivesThe present study aimed to evaluate the efficacy of Aloe vera in the methylcellulose-induced ocular hypertension model.MethodsFifty-six rabbits were randomly divided into seven groups. Intraocular pressure (IOP) was raised by anterior chamber injection of 2% methylcellulose in all the groups except the normal control group. Disease control animals were treated with sterile water and active control with topical 0.5% timolol 12 hourly; 6 and 12% A. vera gel topical solutions 8 hourly were given in group IV and V, respectively; 6 and 12% A. vera gel solutions along with timolol were given in group VI and VII animals, respectively. Mean IOP values and percentage of reduction in IOP were compared at 15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 36 h, and 48 h.ResultsA. vera gel solutions (6 and 12%) showed a significant reduction in mean IOP from 4 to 2 h time points, respectively, whereas, A. vera gel solutions (6 and 12%) + timolol showed significant less mean IOP from a 30 min time point as compared with disease control. A. vera gel solutions (6 and 12%) showed 8.6 and 10.4% more reduction in IOP, respectively (66.8 ± 4.9% and 68.6 ± 5.4% vs. 58.2 ± 2.3%; p > 0.05), whereas 6 and 12% A. vera gel solutions along with timolol showed 14.5 and 16.2% more reduction in IOP, respectively (72.7 ± 4.7% and 74.4 ± 4.1% vs. 58.2 ± 2.3%; p < 0.05), than disease control group at 48 h.ConclusionsSix and twelve percent A. vera gel solutions reduced the IOP effectively. Concurrent treatment with 12% A. vera gel and timolol produced the maximum reduction in IOP.

Space charge capacitance spectroscopy in amorphous silicon Schottky diodes: Theory, modeling, and experiments

2012 ◽  
Vol 358 (17) ◽  
pp. 2007-2010 ◽  
Author(s):  
O.A. Maslova ◽  
M.E. Gueunier-Farret ◽  
J. Alvarez ◽  
A.S. Gudovskikh ◽  
E.I. Terukov ◽  
...  
Keyword(s):  
Space Charge ◽  
Amorphous Silicon ◽  
Schottky Diodes ◽  
Modeling And Experiments ◽  
Capacitance Spectroscopy ◽  
Charge Capacitance

SPACE-CHARGE LAYER, INTRINSIC "BULK" AND SURFACE COMPLEX DEFECTS IN ZnO NANOPARTICLES — A HIGH-FIELD ELECTRON PARAMAGNETIC RESONANCE ANALYSIS

2013 ◽  
Vol 06 (04) ◽  
pp. 1330004 ◽  
Author(s):  
RÜDIGER-A. EICHEL ◽  
EMRE ERDEM ◽  
PETER JAKES ◽  
ANDREW OZAROWSKI ◽  
JOHAN VAN TOL ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Space Charge ◽  
Zno Nanoparticles ◽  
High Field ◽  
Space Charge Layer ◽  
Paramagnetic Resonance ◽  
Charge Layer ◽  
Type Formula ◽  
Field Electron ◽  
Electron Paramagnetic

The defect structure of ZnO nanoparticles is characterized by means of high-field electron paramagnetic resonance (EPR) spectroscopy. Different point and complex defects could be identified, located at the "bulk" or the surface region of the nanoparticles. In particular, by exploiting the enhanced g-value resolution at a Larmor frequency of 406.4 GHz, it could be shown that the resonance commonly observed at g = 1.96 is comprised of several overlapping resonances from different defects. Based on the high-field EPR analysis, the development of a space-charge layer could be monitored that consists of (shallow) donor-type [Formula: see text] defects at the "bulk" and acceptor-type [Formula: see text] and complex [Formula: see text] defects at the surface. Application of a core-shell model allows to determine the thickness of the depletion layer to 1.0 nm for the here studied compounds [J.J. Schneider et al., Chem. Mater.22, 2203 (2010)].

ACTIVATION ENERGY FOR HOLE INJECTION AND ANALYSIS OF THE SPACE CHARGE LAYER IN ANTHRACENE CRYSTALS

1974 ◽  
Vol 3 (12) ◽  
pp. 1459-1462
Author(s):  
Masahiro Kotani ◽  
Yoko Watanabe ◽  
Tomoko Kato
Keyword(s):  
Activation Energy ◽  
Space Charge ◽  
Space Charge Layer ◽  
Hole Injection ◽  
Charge Layer

scholarly journals Vitamin C ameliorates tetrahydrocannabinol-induced spermatotoxicity in-vitro

2020 ◽  
Author(s):  
Abdullateef Isiaka Alagbonsi ◽  
Luqman Aribidesi Olayaki
Keyword(s):  
Vitamin C ◽  
Cannabinoid Receptors ◽  
Group Iv ◽  
Group Vi ◽  
Spermatozoa Motility ◽  
Progressive Motility ◽  
Straight Line ◽  
Lateral Head

Abstract Background: We investigated the in-vitro effects of vitamin C on delta-9-tetrahydrocannabinol (THC) -induced reduction in spermatozoa motility and kinematics. Methods: Six rats were used for the study. Semen from each of the 6 rats was randomly divided into 6 groups such that each rat’s semen was in all of the groups. Groups I-III received placebo, THC (1 mM), and vitamin C (5 mM) respectively. Group IV was pretreated with cannabinoid receptors’ blockers (CBs-) 1 and 2, followed by THC. Groups V and VI received THC and vitamin C, but group VI was additionally pre-treated with CBs-. Results: The spermatozoa progressive motility, average path velocity (VAP), curvilinear velocity (VCL), straight-line velocity (VSL), amplitude of lateral head (ALH) and beat cross frequency (BCF) were reduced by THC (6.08±1.16%; 5.64±0.82 µm/s; 6.96±0.74 µm/s; 2.75±0.23 µm/s; 0.31±0.02 µm; and 0.78±0.08 Hz respectively) but increased by vitamin C (51.20±1.32 %; 17.90±0.21 µm/s; 25.11±0.96 µm/s; 8.80±0.27 µm/s; 0.75±0.01 µm; and 3.15±0.03 Hz respectively) when compared to control (39.72±0.38 %; 13.70±0.29 µm/s; 18.04±0.58 µm/s; 7.54±0.34 µm/s; 0.65±0.02 µm; and 2.79±0.01 Hz respectively). Vitamin C inhibited the THC-induced reduction in these parameters (37.36±0.73 %; 10.98±0.45 µm/s; 13.58±0.30 µm/s; 7.11±0.22 µm/s; 0.58±0.01 µm; and 2.60±0.01 Hz respectively) in the absence of CBs- 1 and 2, and even caused additional increases in progressive motility (49.54±1.01 %), VAP (15.70±0.38 µm/s) and VCL (22.53±0.29 µm/s) above the control levels with CBs-.Conclusion: Vitamin C ameliorates the THC-induced reduction in spermatozoa motility in-vitro by modulation of their kinematics.

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