High Resistivity InAIN by Nitrogen or Oxygen Implantation

1995 ◽  
Vol 378 ◽  
Author(s):  
J. C. Zolper ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
C. B. Vartuli
Keyword(s):  
Sheet Resistance ◽  
Fold Increase ◽  
Temperature Data ◽  
Conduction Band Edge ◽  
High Resistivity ◽  
High Dose ◽  
Defect Level ◽  
Order Of Magnitude ◽  
Anneal Temperature ◽  
Magnitude Increase

AbstractWe report on the isolation properties of In0.75Al0.25N implanted with either N or O for several doses and post-implant anneal temperatures. Sheet resistance versus anneal temperature data are reported for the various implants with a maximum sheet resistance of <1×109 Ω/□ achieved for a high dose N-implant annealed at 600 or 700 °C and <5×108 Ω/□ achieved for a high dose O-implant annealed at 600 °C. These sheet resistances correspond to a greater than three order of magnitude increase over the as-grown values. The compensating defect level for the highest resistance N-implanted sample has an estimate ionization level 580 meV below the conduction band edge. Implant isolation of InAIN is also compared to oxygen implant isolation of InxGa1-xN — where only a 50 to 100 fold increase in sheet resistance is observed — to study the effect of Al in the isolation scheme.

ION IMPLANTATION OF SILICON: II. ELECTRICAL EVALUATION USING HALL-EFFECT MEASUREMENTS

1967 ◽  
Vol 45 (12) ◽  
pp. 4073-4089 ◽  
Author(s):  
J. W. Mayer ◽  
O. J. Marsh ◽  
G. A. Shifrin ◽  
R. Baron
Keyword(s):  
Hall Effect ◽  
Carrier Concentration ◽  
Room Temperature ◽  
Weighted Average ◽  
Preceding Paper ◽  
Amorphous Layer ◽  
Scattering Data ◽  
High Dose ◽  
Order Of Magnitude ◽  
Magnitude Increase

Hall-effect and sheet-resistivity measurements have been made on silicon samples implanted with Sb, Ga, and As ions at energies between 20 and 75 keV. These measurements determine the weighted average of the number Ns of carriers/cm2 and the carrier mobility in the implanted layer. A combination of Hall measurements and layer-removal techniques was used in some cases to obtain a more accurate value of the number of carriers/cm2 and the depth dependence of the carrier concentration and mobility.For Sb implantations both temperature and dose affect the anneal characteristics. Silicon samples implanted with Sb at room temperature exhibited n-type behavior following anneal at 300 °C, with little increase in Ns up to about 550 °C anneal temperatures. A 600 °C 10-minute anneal produced an order-of-magnitude increase in Ns. This change is associated with reordering of the amorphous layer created during room-temperature implantations. This amorphous layer is not produced in implantations made at temperatures above 450 °C. In low-dose (<1014/cm2) Sb implantations at 500 °C, Ns increased by a factor of 2 to 3 during anneal to 800 °C. In high-dose (>5 × 1014/cm2) Sb implantations, the carrier concentration exceeded the limit set by thermal equilibrium solubility of Sb in silicon. Under these conditions, annealing caused a decrease in Ns toward the value associated with the solubility.Such supersaturation effects were not observed in Ga and As implantations at 500 °C. Annealing to temperatures of 800–900 °C produced a one-to-two order-of-magnitude increase in the number of carriers/cm2. In Ga implantations annealed to 800–900 °C, the number of carriers/cm2 increased approximately linearly with increasing dose and then leveled off at a value near that expected from thermal solubility.The Rutherford-scattering data in the preceding paper indicates that the difference in implantation behavior between various ion species is due to differences in the relative number of ions on substitutional sites.

UV Resistant Poly(3,4-ethylenedioxythiophene) Thin Films: Layer-by-Layer Assembly with Absorbing Nanoparticles

2007 ◽  
Vol 1054 ◽  
Author(s):  
Thomas Dawidczyk ◽  
Jaime Grunlan
Keyword(s):  
Thin Films ◽  
Sheet Resistance ◽  
Film Growth ◽  
Environmental Stability ◽  
Layer By Layer ◽  
Bulk Resistivity ◽  
Flexible Display ◽  
Lbl Assembly ◽  
Order Of Magnitude ◽  
Magnitude Increase

ABSTRACTLayer-by-layer (LbL) assembly is used to create thin films by alternately exposing a substrate to positively- and negatively-charged molecules or particles in water. In recent years, LbL assemblies containing poly(3,4-ethylenedioxythiophene) (PEDOT) have been heavily studied, but little work has focused on improving the environmental stability of these thin films. Most intrinsically conductive polymers suffer from increasing resistance with exposure to ultraviolet light. In the present work, photolytic stability is improved by adding UV-absorbing nanoparticles to PEDOT assemblies. Films made by alternately depositing PEDOT-PSS and polyethylenimine (PEI) show an order of magnitude increase in sheet resistance after just 28 hours of exposure to 365 nm light. This degradation is cut in half by incorporating UV-absorbing nanoparticles, carbon black or titanium dioxide, into these assemblies. After more than 200 hours of exposure, films containing TiO2 nanoparticles have sheet resistance that is one fifth that of the unprotected PEDOT. In addition to adding UV-absorbing particles, the influence of doping and type of polycation on bulk resistivity and film growth were evaluated. These films are able to achieve bulk resistivity values below 1 Ohm cm with a thickness below 100 nm. When combined with transparency greater than 90%, these films may be useful for electrostatic dissipation layers or low conductivity electrodes in film or flexible display applications.

scholarly journals Order of magnitude increase in photocatalytic rate for hierarchically porous anatase thin films synthesized from zinc titanate coatings

2017 ◽  
Vol 46 (6) ◽  
pp. 1975-1985 ◽  
Author(s):  
Nathanya J. Platt ◽  
Karl M. Kaye ◽  
Gregory J. Limburn ◽  
Samuel D. Cosham ◽  
Alexander N. Kulak ◽  
...  
Keyword(s):  
Thin Films ◽  
Fold Increase ◽  
Zinc Titanate ◽  
Hierarchically Porous ◽  
Porous Titania ◽  
Order Of Magnitude ◽  
Titania Films ◽  
Magnitude Increase

Zinc titanate films are converted into porous anatase showing a 12-fold increase in rate compared to non-porous titania films.

scholarly journals Hydraulic transmissivity inferred from ice-sheet relaxation following Greenland supraglacial lake drainages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ching-Yao Lai ◽  
Laura A. Stevens ◽  
Danielle L. Chase ◽  
Timothy T. Creyts ◽  
Mark D. Behn ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Ice Sheet ◽  
Drainage System ◽  
Greenland Ice Sheet ◽  
Field Observations ◽  
Surface Uplift ◽  
Drainage Networks ◽  
Order Of Magnitude ◽  
Lake Drainage ◽  
Magnitude Increase

AbstractSurface meltwater reaching the base of the Greenland Ice Sheet transits through drainage networks, modulating the flow of the ice sheet. Dye and gas-tracing studies conducted in the western margin sector of the ice sheet have directly observed drainage efficiency to evolve seasonally along the drainage pathway. However, the local evolution of drainage systems further inland, where ice thicknesses exceed 1000 m, remains largely unknown. Here, we infer drainage system transmissivity based on surface uplift relaxation following rapid lake drainage events. Combining field observations of five lake drainage events with a mathematical model and laboratory experiments, we show that the surface uplift decreases exponentially with time, as the water in the blister formed beneath the drained lake permeates through the subglacial drainage system. This deflation obeys a universal relaxation law with a timescale that reveals hydraulic transmissivity and indicates a two-order-of-magnitude increase in subglacial transmissivity (from 0.8 ± 0.3 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 to 215 ± 90.2 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 ) as the melt season progresses, suggesting significant changes in basal hydrology beneath the lakes driven by seasonal meltwater input.

scholarly journals Review of the soft-X-ray laser research at CEL-V

1991 ◽  
Vol 9 (2) ◽  
pp. 493-499
Author(s):  
D. Naccache ◽  
J-L. Bourgade ◽  
P. Combis ◽  
C. J. Keane ◽  
J-P. Le Breton ◽  
...  
Keyword(s):  
Atomic Number ◽  
Collisional Excitation ◽  
X Ray ◽  
Order Of Magnitude ◽  
Laser Experiments ◽  
Magnitude Increase

We present some significant results of collisional excitation X-ray laser experiments in plasmas produced by a laser. We studied the amplification in Ne- and Ni-like ions by varying both the nature and the thickness of targets, the irradiation, and the wavelength of the driving laser. Some potentially interesting scalings as a function of the atomic number of the lasing element are demonstrated in the Ne-like system. An order-of-magnitude increase in gain in the Ni-like experiments was determined.

Critical current density and microstructure variations in YBa2Cu3O7−x + BaSnO3 films with different concentrations of BaSnO3

2008 ◽  
Vol 23 (12) ◽  
pp. 3363-3369 ◽  
Author(s):  
C.V. Varanasi ◽  
J. Burke ◽  
L. Brunke ◽  
H. Wang ◽  
J.H. Lee ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Gradual Increase ◽  
Critical Transition ◽  
Critical Transition Temperature ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
High Fields ◽  
Magnitude Increase

Previous work on YBa2Cu3O7−x (YBCO) + BaSnO3 (BSO) films with a single composition showed significant critical current density (Jc) improvements at higher fields but lowered Jc in low fields. A detailed study on BSO concentrations provided here demonstrates that significant Jc enhancement can occur even up to 20 mol% BSO inclusion, where typical particulate inclusions in these concentrations degrade the YBCO performance. YBCO + BSO films were processed on (100) LaAlO3 substrates using premixed targets of YBa2Cu3O7-x (YBCO) with additions of 2, 4, 10, and 20 mol% BSO. The critical transition temperature Tc of the films remained high (>87 K), even with large amounts (20 mol%) of BSO. YBCO + BSO films showed a gradual increase in Jc at high fields as the amount of BSO was increased. More than an order of magnitude increase in Jc was measured in YBCO + BSO samples as compared to regular YBCO at 4 T. YBCO + 10 mol% BSO films showed overall improvement at all the field ranges while YBCO + 20 mol% BSO was better only at high fields. Transmission electron microscopy revealed the presence of ∼7–8-nm-diameter BSO nanocolumns, the density of which increased with increasing BSO content correlating well with the observed improvements in Jc.

scholarly journals Nearfield trapping increases lifetime of single-molecule junction by one order of magnitude

2020 ◽  
Author(s):  
Albert C. Aragonès ◽  
Katrin F. Domke
Keyword(s):  
Molecular Electronics ◽  
Single Molecule ◽  
Fold Increase ◽  
Trapping Efficiency ◽  
Non Invasive ◽  
Order Of Magnitude ◽  
Molecule Junction ◽  
Single Molecule Junction ◽  
The Difference ◽  
Power Densities

Abstract Progress in molecular electronics (ME) is largely based on improved understanding of the properties of single molecules (SM) trapped for seconds or longer to enable their detailed characterization. We present a plasmon-supported break-junction (PBJ) platform to significantly increase the lifetime of SM junctions of 1,4-benzendithiol (BDT) without the need for chemical modification of molecule or electrode. Moderate far-field power densities of ca. 11 mW/µm2 lead to a >10-fold increase in minimum lifetime compared to laser-OFF conditions. The nearfield trapping efficiency is twice as large for bridge-site contact compared to hollow-site geometry, which can be attributed to the difference in polarizability. Current measurements and tip-enhanced Raman spectra confirm that native structure and contact geometry of BDT are preserved during the PBJ experiment. By providing a non-invasive pathway to increase short lifetimes of SM junctions, PBJ is a valuable approach for ME, paving the way for improved SM sensing and recognition platforms.

scholarly journals Large-area printing of ferroelectric surface and super-domains for efficient solar water splitting

2020 ◽  
Author(s):  
Yu Tian ◽  
Yaqing Wei ◽  
Minghui Pei ◽  
Rongrong Cao ◽  
Zhenao Gu ◽  
...  
Keyword(s):  
Water Splitting ◽  
Electric Fields ◽  
Electronic Structures ◽  
Active Sites ◽  
Large Area ◽  
Solar Water Splitting ◽  
High Efficient ◽  
Catalytic Sites ◽  
Order Of Magnitude ◽  
Magnitude Increase

Abstract Surface electronic structures of the photoelectrodes determine the activity and efficiency of the photoelectrochemical water splitting, but the controls of their surface structures and interfacial chemical reactions remain challenging. Here, we use ferroelectric BiFeO3 as a model system to demonstrate an efficient and controllable water splitting reaction by large-area constructing the hydroxyls-bonded surface. The up-shift of band edge positions at this surface enables and enhances the interfacial holes and electrons transfer through the hydroxyl-active-sites, leading to simultaneously enhanced oxygen and hydrogen evolutions. Furthermore, printing of ferroelectric super-domains with microscale checkboard up/down electric fields separates the distribution of reduction/oxidation catalytic sites, enhancing the charge separation and giving rise to an order of magnitude increase of the photocurrent. This large-area printable ferroelectric surface and super-domains offer an alternative platform for controllable and high-efficient photocatalysis.

scholarly journals Hydrodechlorination of CHClF2 (HCFC-22) over Pd-Pt catalysts supported on thermally modified activated carbon. Beneficial effect of catalyst oxidation.

2021 ◽  
Author(s):  
Monika Radlik ◽  
Wojciech Juszczyk ◽  
Wioletta Raróg-Pilecka ◽  
Magdalena Zybert ◽  
Zbigniew Karpiński
Keyword(s):  
Alloy Composition ◽  
Active Surface ◽  
Metal Particles ◽  
Pt Catalysts ◽  
Modified Activated Carbon ◽  
Palladium Surface ◽  
Order Of Magnitude ◽  
Carbon Burning ◽  
Magnitude Increase ◽  
Catalyst Oxidation

Pd-Pt catalysts supported on carbon preheated to 1600&deg;C have been reinvestigated in CHFCl2 hydrodechlorination. An additionally adopted catalyst oxidation at 350-400&deg;C produced an order of magnitude increase in the catalytic activity of Pd/C. This increase is not caused by changes in metal dispersion or possible decontamination of the Pd surface from superficial carbon, but rather by unlocking the active surface, originally inaccessible in metal particles tightly packed in the pores of carbon. Burning carbon from the pore walls attached to the metal changes the pore structure, providing easier access for the reactants to the entire palladium surface. As upon calcination the performance of the rest of the Pd-Pt/C catalysts changes less than for Pd/C, the relation between the turnover frequency and alloy composition does not confirm the Pd-Pt synergy invoked in our previous work. The use of even higher-preheated carbon (1800&deg;C), completely free of micropores, results in a Pd/C catalyst that does not need to be oxidized to achieve high activity and excellent selectivity up to CH2F2 (&gt;90%).

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