The Donor State of Vanadium in Indium Phosphide

1985 ◽  
Vol 46 ◽  
Author(s):  
Georges Bremond ◽  
A. Nouailhat ◽  
G. Guillot ◽  
B. Deveaud ◽  
B. Lambert ◽  
...  
Keyword(s):  
Excited State ◽  
Indium Phosphide ◽  
Valence Band ◽  
Cross Sections ◽  
Donor Level ◽  
Donor State ◽  
P Type ◽  
First Time

AbstractWe have performed studies on Vanadium doped InP, especially p-type InP codoped with Zn and V. Luminescence excitation experiments, DLTS, DLOS and absorption experiments lead to the conclusion that the donor level (V3+/V4+) of Vanadium is at about 0.2 eV above the valence band. Optical cross-sections that are determined by DLOS allow to observe for the first time a resonance in the valence band of a III-V semiconductor that we tentatively interpret as an excited state of V4+.

DONOR LEVEL OF INTERSTITIAL HYDROGEN IN GaAs

1991 ◽  
Vol 05 (13) ◽  
pp. 877-880 ◽  
Author(s):  
B. CLERJAUD ◽  
F. GENDRON ◽  
M. KRAUSE ◽  
W. ULRICI
Keyword(s):  
Charge State ◽  
Valence Band ◽  
Positive Charge ◽  
Hydrogen Donor ◽  
Type Material ◽  
Donor Level ◽  
P Type ◽  
Interstitial Hydrogen

The carbon-hydrogen complex in GaAs only forms in p-type material. Diffusing hydrogen has to be in a positive charge state for such a complex to be formed. The corresponding hydrogen donor level is shown to be located around 0.5 eV above the top of the valence band.

Deep Level Related Yellow Luminescence in P-Type GaN Grown by MBE on (0001) Sapphire

1999 ◽  
Vol 595 ◽  
Author(s):  
Giancarlo Salviati ◽  
Nicola Armani ◽  
Carlo Zanotti-Fregonara ◽  
Enos Gombia ◽  
Martin Albrecht ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Deep Level ◽  
Cubic Phase ◽  
Donor Level ◽  
Yellow Luminescence ◽  
Wurtzite Phase ◽  
Shallow Acceptor ◽  
Deep Donor ◽  
P Type ◽  
Deep Donor Level

AbstractYellow luminescence (YL) has been studied in GaN:Mg doped with Mg concentrations ranging from 1019 to 1021 cm−3 by spectral CL (T=5K) and TEM and explained by suggesting that a different mechanism could be responsible for the YL in p-type GaN with respect to that acting in n-type GaN.Transitions at 2.2, 2.8, 3.27, 3.21, and 3.44 eV were found. In addition to the wurtzite phase, TEM showed a different amount of the cubic phase in the samples. Nano tubes with a density of 3×109 cm−2 were also observed by approaching the layer/substrate interface. Besides this, coherent inclusions were found with a diameter in the nm range and a volume fraction of about 1%.The 2.8 eV transition was correlated to a deep level at 600 meV below the conduction band (CB) due to MgGa-VN complexes. The 3.27 eV emission was ascribed to a shallow acceptor at about 170-190 meV above the valence band (VB) due to MgGa.The 2.2 eV yellow band, not present in low doped samples, increased by increasing the Mg concentration. It was ascribed to a transition between a deep donor level at 0.8-1.1 eV below the CB edge due to NGa and the shallow acceptor due to MgGa. This assumption was checked by studying the role of C in Mg compensation. CL spectra from a sample with high C content showed transitions between a C-related 200 meV shallow donor and a deep donor level at about 0.9- 1.1 eV below the CB due to a NGa-VN complex. In our hypothesis this should induce a decrease of the integrated intensity in both the 2.2 and 2.8 eV bands, as actually shown by CL investigations.

12 kV 4H-SiC p-IGBTs with Record Low Specific On-Resistance

2008 ◽  
Vol 600-603 ◽  
pp. 1187-1190 ◽  
Author(s):  
Q. Jon Zhang ◽  
Charlotte Jonas ◽  
Joseph J. Sumakeris ◽  
Anant K. Agarwal ◽  
John W. Palmour
Keyword(s):  
Carrier Lifetime ◽  
Drift Region ◽  
Gate Bias ◽  
Enhancement Layer ◽  
Channel Mobility ◽  
Dc Characteristics ◽  
Blocking Voltage ◽  
High Carrier ◽  
P Type ◽  
First Time

DC characteristics of 4H-SiC p-channel IGBTs capable of blocking -12 kV and conducting -0.4 A (-100 A/cm2) at a forward voltage of -5.2 V at 25°C are demonstrated for the first time. A record low differential on-resistance of 14 mW×cm2 was achieved with a gate bias of -20 V indicating a strong conductivity modulation in the p-type drift region. A moderately doped current enhancement layer grown on the lightly doped drift layer effectively reduces the JFET resistance while maintains a high carrier lifetime for conductivity modulation. A hole MOS channel mobility of 12.5 cm2/V-s at -20 V of gate bias was measured with a MOS threshold voltage of -5.8 V. The blocking voltage of -12 kV was achieved by Junction Termination Extension (JTE).

First-Principles Study on the Conductive Properties of P-Doped ZnO

2009 ◽  
Vol 79-82 ◽  
pp. 1253-1256 ◽  
Author(s):  
Li Guan ◽  
Qiang Li ◽  
Xu Li ◽  
Jian Xin Guo ◽  
Bo Geng ◽  
...  
Keyword(s):  
Fermi Level ◽  
Valence Band ◽  
Density Functional ◽  
Lattice Structure ◽  
Mulliken Charge ◽  
Total Density ◽  
Type Conductivity ◽  
Doped Zno ◽  
P Type ◽  
Conductive Properties

In the present paper, the lattice structure, band structure and density of state of pure and P-doped ZnO are calculated by first-principle method based on density functional theory. By analyzing the Mulliken charge overlap population and bond length, it is found that the bond of P-Zn is longer and stronger than O-Zn bond for PO-ZnO. But for PZn-ZnO, the O-P bond becomes shorter and more powerful than O-Zn bond. Also, weak O-O bonds are formed in this case. Our results show that the final total energy of PO-ZnO is lower than PZn-ZnO. The lattice structure of PO-ZnO is more stability than PZn-ZnO. For PO-ZnO, The Fermi level moves into the valence band, which expresses that the holes appear on the top of valence band and thus the PO-ZnO exhibits p-type conductivity. For PZn-ZnO, the Fermi level moves up to the conductor band and the total density of states shifts to the lower energy region, thus PZn-ZnO shows the n-type conductivity.

GalnAsSb Materials for Thermophotovoltaics

1996 ◽  
Vol 450 ◽  
Author(s):  
C. A. Wang ◽  
G. W. Turner ◽  
M. J. Manfra ◽  
H. K. Choi ◽  
D. L. Spears
Keyword(s):  
Room Temperature ◽  
Molecular Beam ◽  
Hole Concentration ◽  
Organometallic Vapor Phase Epitaxy ◽  
Room Temperature Photoluminescence ◽  
P Type ◽  
First Time ◽  
Lattice Matched ◽  
Comparable Quality ◽  
Peak Emission

ABSTRACTGai1−xInxASySb1-y (0.06 < x < 0.18, 0.05 < y < 0.14) epilayers were grown lattice-matched to GaSb substrates by low-pressure organometallic vapor phase epitaxy (OMVPE) using triethylgallium, trimethylindium, tertiarybutylarsine, and trimethylantimony. These epilayers have a mirror-like surface morphology, and exhibit room temperature photoluminescence (PL) with peak emission wavelengths (λP,300K) out to 2.4 μm. 4K PL spectra have a full width at half-maximum of 11 meV or less for λP,4K < 2.1 μm (λP,300K = 2.3 μm). Nominally undoped layers are p-type with typical 300K hole concentration of 9 × 1015 cm−3 and mobility ∼ 450 to 580 cm2/V-s for layers grown at 575°C. Doping studies are reported for the first time for GalnAsSb layers doped n type with diethyltellurium and p type with dimethylzinc. Test diodes of p-GalnAsSb/n-GaSb have an ideality factor that ranges from 1.1 to 1.3. A comparison of electrical, optical, and structural properties of epilayers grown by molecular beam epitaxy indicates OMVPE-grown layers are of comparable quality.

The Mechanics of the Secondary Flows of Viscoelastic Fluids in Non-Circular Straight Tubes and the Mean Transversal Field in Pulsating Flows

2000 ◽  
Author(s):  
Dennis A. Siginer ◽  
Mario F. Letelier
Keyword(s):  
Secondary Flow ◽  
Cross Sections ◽  
Viscoelastic Fluids ◽  
Secondary Flows ◽  
Novel Approach ◽  
Transversal Field ◽  
Time Domains ◽  
Viscoelastic Liquids ◽  
First Time ◽  
Secondary Flow Field

Abstract A survey of secondary flows of viscoelastic liquids in straight tubes is given including recent work pointing at striking analogies with transversal deformations associated with the simple shearing of solid materials. The importance and implications of secondary flows of viscoelastic fluids in heat transfer enhancement are explored together with the difficulties in detecting weak secondary flows (dilute, weakly viscoelastic solutions) in a laboratory setting. Recent new work by the author and colleagues which explores for the first time the structure of the secondary flow field in the pulsating flow of a constitutively nonlinear simple fluid, whose structure is defined by a series of nested integrals over semi-infinite time domains, in straight tubes of arbitrary cross-sections is summarized. The transversal field arises at the second order of the perturbation of the nonlinear constitutive structure, and is driven by first order terms which define the linearly viscoelastic longitudinal flow in the hierarchy of superposed linear flows stemming from the perturbation of the constitutive structure. Arbitrary conduit contours are obtained through a novel approach to the concept of domain perturbation. Time averaged, mean secondary flow streamline contours are presented for the first time for triangular, square and hexagonal pipes.

Synthesis, crystal structure and thermoelectric properties of a new metal telluride Ba3Ag3InTe6

2017 ◽  
Vol 4 (9) ◽  
pp. 1458-1464 ◽  
Author(s):  
M.-Y. Lee ◽  
D. I. Bilc ◽  
E. Symeou ◽  
Y.-C. Lin ◽  
I.-C. Liang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Transport Properties ◽  
Valence Band ◽  
Thermoelectric Properties ◽  
Type Semiconductor ◽  
P Type

A new p-type semiconductor Ba3Ag3InTe6 with transport properties dominated by the layer [Ag3Te4]5− distributed in the valence band.

The effect of device geometry and crystal orientation on the stress-dependent offset voltage of 3C–SiC(100) four terminal devices

2015 ◽  
Vol 3 (34) ◽  
pp. 8804-8809 ◽  
Author(s):  
Afzaal Qamar ◽  
Hoang-Phuong Phan ◽  
Jisheng Han ◽  
Philip Tanner ◽  
Toan Dinh ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Orientation ◽  
Offset Voltage ◽  
Device Geometry ◽  
Stress Dependent ◽  
P Type ◽  
The Impact ◽  
First Time

This communication reports for the first time, the impact of device geometry on the stress-dependent offset voltage of single crystal p-type 3C–SiC four terminal devices.

Quantum-Confined Optical Interband Transitions in 5-Doped Doping Superlattices

1989 ◽  
Vol 145 ◽  
Author(s):  
E. F. Schubert ◽  
T. D. Harris ◽  
J. E. Cunningham
Keyword(s):  
Emission Spectra ◽  
Doping Profile ◽  
Luminescence Spectra ◽  
Interband Transitions ◽  
Doping Technique ◽  
Quantum Confined ◽  
P Type ◽  
First Time ◽  
Experimental Absorption ◽  
Good Agreement

AbstractOptical absorption and photoluminescence experiments are performed on GaAs doping superlattices, which have a δ-function-like doping profile of alternating n-type and p-type dopant sheets. Absorption and emission spectra reveal for the first time the clear signature of quantum-confined interband transitions. The peaks of the experimental absorption and luminescence spectra are assigned to calculated energies of quantum-confined transitions with very good agreement. It is shown that the employment of the δ-doping technique results in improved optical properties of doping superlattices.

scholarly journals Performance Evaluation of a Nanomaterial-Based Thermoelectric Generator with Tapered Legs

2020 ◽  
Vol 7 ◽  
pp. 48-54
Author(s):  
Marilyn A. Ebiringa ◽  
John Paul Adimonyemma ◽  
Chika Maduabuchi
Keyword(s):  
Cross Sections ◽  
Thermoelectric Generator ◽  
Bulk Material ◽  
Electrical Energy ◽  
Ansys Software ◽  
Thermoelectric Effects ◽  
Trapezoidal Shape ◽  
Solar Radiation Intensity ◽  
Geometry Configuration ◽  
First Time

A thermoelectric generator (TEG) converts thermal energy to electricity using thermoelectric effects. The amount of electrical energy produced is dependent on the thermoelectric material properties. Researchers have applied nanomaterials to TEG systems to further improve the device’s efficiency. Furthermore, the geometry of the thermoelectric legs has been varied from rectangular to trapezoidal and even X-cross sections to improve TEG’s performance further. However, up to date, a nanomaterial TEG that uses tapered thermoelectric legs has not been developed before. The most efficient nanomaterial TEGs still make use of the conventional rectangular leg geometry. Hence, for the first time since the conception of nanostructured thermoelectrics, we introduce a trapezoidal shape configuration in the device design. The leg geometries were simulated using ANSYS software and the results were post-processed in the MATLAB environment. The results show that the power density of the nanoparticle X-leg TEG was 10 times greater than that of the traditional bulk material semiconductor X-leg TEG. In addition, the optimum leg geometry configuration in a nanomaterial-based TEG is dependent on the operating solar radiation intensity.

Sign in / Sign up

Export Citation Format

Share Document