Enhanced Charge Carrier Concentration of SiC/CNT With N- and P-Type Doping Agents

2014 ◽  
Author(s):  
Kyle Edwards ◽  
Mujibur Khan ◽  
Rafael Quirino ◽  
Brenda Beckler ◽  
Saheem Absar
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Raman Spectra ◽  
Structural Changes ◽  
Charge Carrier Concentration ◽  
X Ray ◽  
Seebeck Coefficients ◽  
P Type ◽  
Conductive Properties ◽  
Walled Carbon Nanotubes

Single-walled Carbon nanotubes (SWCNTs) have been shown to have excellent conductive properties. SWCNTs were dispersed in a SiC nanoparticle matrix to form a homogeneous mixture that is both mechanically durable and conductive. The SWCNT amount has been varied. SiC/SWCNT mixtures were then doped with various N- and P-type agents, and the resulting samples were analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Raman spectra of the samples were also measured for evidence of structural changes. Seebeck coefficients were measured for the doped samples demonstrating the change in thermoelectric properties. Shifts in the G peak (1580.6 cm-1) of the Raman spectra of the samples provides evidence of an increase in charge carrier concentration in the doped samples, correlating well with the Seebeck coefficient results.

scholarly journals Charge carrier concentration optimization of thermoelectric p-type half-Heusler compounds

APL Materials ◽  
2015 ◽  
Vol 3 (4) ◽  
pp. 041516 ◽  
Author(s):  
Elisabeth Rausch ◽  
Benjamin Balke ◽  
Torben Deschauer ◽  
Siham Ouardi ◽  
Claudia Felser
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Charge Carrier Concentration ◽  
Heusler Compounds ◽  
P Type

Uniform Axial Charge Carrier Concentration in PVT-Grown p-Type 6H SiC by Non-Uniform Distribution of Boron in the Powder Source

2004 ◽  
Vol 457-460 ◽  
pp. 719-722
Author(s):  
Z.G. Herro ◽  
Matthias Bickermann ◽  
Boris M. Epelbaum ◽  
Roland Weingärtner ◽  
Ulrike Künecke ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Uniform Distribution ◽  
Carrier Concentration ◽  
Charge Carrier Concentration ◽  
Axial Charge ◽  
P Type

scholarly journals Ohmic contacts to p-GaN Using Au/Ni-Mg-O Metallization

2010 ◽  
Vol 61 (6) ◽  
pp. 378-381 ◽  
Author(s):  
Jozef Liday ◽  
Peter Vogrinčič ◽  
Ivan Hotový ◽  
Alberta Bonanni ◽  
Helmut Sitter ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Contact Resistance ◽  
Carrier Concentration ◽  
Ohmic Contacts ◽  
Surface Region ◽  
Charge Carrier Concentration ◽  
Contact Structures ◽  
Low Concentration ◽  
P Type ◽  
Elemental Depth

Ohmic contacts to p-GaN Using Au/Ni-Mg-O Metallization Electrical characteristics and elemental depth profiles of ohmic contacts to p-GaN using Au/Ni-Mg-Ox metallization have been investigated. The objective was to examine the possibilities of increasing the charge carrier concentration in the surface region of GaN by adding Mg, thus of a p-type dopant into the Au/NiOx metallization structure. For this purpose, a Ni-Mg-Ox layer with a low concentration of Mg was deposited on p-GaN by dc reactive magnetron sputtering. The top Au layer was deposited in a similar way. The fabricated contact structures were annealed in N2. When the Ni-Mg layer in the Au/Ni-Mg-Ox/p-GaN structure was deposited in an atmosphere with a low concentration of oxygen (0.2 at%), the structure exhibited a low resistance ohmic nature. The contact resistance was lower than in the case of a Au/Ni-Ox/p-GaN structure without the Mg dopant in the metallic layer. An increase in the concentration of oxygen in the working atmosphere resulted in higher values of the contact resistance of the Au/Ni-Mg-Ox/p-GaN structure. In our opinion the ohmic nature of the contact structure is related to the existence of a metal/p-NiO/p-GaN scheme. The measured values of the contact resistance in the Au/Ni-Mg-Ox/p-GaN structure in comparison with the Au/Ni-Ox/p-GaN structure are caused by an increased charge carrier concentration in the surface region of p-GaN, which is a consequence of Mg diffusion from the Ni-Mg-Ox layer.

CuK-EDGE STUDIES OF THE CHARGE CARRIES IN Th-DOPED CUPRATE SYSTEM R2-xThxCuO4-δ (R=Nd, Sm AND Gd)

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3750-3754
Author(s):  
G. LIANG ◽  
Y. YI ◽  
R. F. JARDIM ◽  
L. V. WANG
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Doping Level ◽  
Cuprate Superconductors ◽  
Charge Carrier Concentration ◽  
Intensity Data ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption ◽  
Compound Series

To further study the charge carrier concentration in electron doped cuprate superconductors. a systematic x-ray absorption near edge structure (XANES) measurement has been carried out on Th-doped superconductor system R 2-x Th x CuO 4-δ (R=Nd, Sm, and Gd). The XANES results show that, similar to the Ce-doped compounds, while the intensity of the Cu 1+4pπ feature increase with the increase of the Th doping level x, the intensities of the Cu 2+4pπ and 4pσ features decreases. This clearly indicates that the electrons doped by the Th atoms are injected into the local Cu 3d-orbitals. The normalized Cu 1+4pπ intensity data show that the Cu 1+ concentration in the Th-doped compound series with different R-elements is linearly proportional to the Th doping-level x. The data suggest that both Ce and Th donate the same fraction of electrons into the Cu sites.

scholarly journals Электрофизические свойства нелегированных и легированных мышьяком эпитаксиальных слоев Hg-=SUB=-1-x-=/SUB=-Cd-=SUB=-x-=/SUB=-Te p-типа проводимости с x~0.4, выращенных методом MOCVD

2018 ◽  
Vol 52 (6) ◽  
pp. 554
Author(s):  
В.С. Евстигнеев ◽  
В.С. Варавин ◽  
А.В. Чилясов ◽  
В.Г. Ремесник ◽  
А.Н. Моисеев ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Chemical Vapor ◽  
Charge Carrier Concentration ◽  
Recombination Mechanism ◽  
Temperature Dependences ◽  
Temperature Equilibrium ◽  
Activation Annealing ◽  
P Type ◽  
Fundamental Limitation

AbstractThe temperature dependences of the charge-carrier concentration and lifetime of minority carriers in undoped and arsenic-doped p -type Hg_1 – x Cd_ x Te epitaxial layers with x ≈ 0.4 grown by the MOCVD-IMP (metalorganic chemical vapor deposition–interdiffusion multilayer process) method are studied. It is shown that the temperature dependences of the charge-carrier concentration can be described by a model assuming the presence of one acceptor and one donor level. The ionization energies of acceptors in the undoped and arsenic-doped materials are 14 and 3.6 meV, respectively. It is established that the dominant recombination mechanism in the undoped layers is Shockley–Read–Hall recombination, and after low-temperature equilibrium annealing in mercury vapors (230°C, 24 h), the dominant mechanism is radiative recombination. The fundamental limitation of the lifetime in the arsenic-doped material is caused by the Auger-7 process. Activation annealing (360°C, 2 h) of the doped layers makes it possible to attain the 100% activation of arsenic.

Photoluminescence-Topography of the p-Type Doped SiC Wafers for Determination of Doping Inhomogeneity

2009 ◽  
Vol 615-617 ◽  
pp. 259-262
Author(s):  
Felix Oehlschläger ◽  
Sandrine Juillaguet ◽  
Hervé Peyre ◽  
Jean Camassel ◽  
Peter J. Wellmann
Keyword(s):  
Low Temperature ◽  
Charge Carrier ◽  
Carrier Concentration ◽  
Charge Carrier Concentration ◽  
Powerful Method ◽  
Carrier Distribution ◽  
Pl Intensity ◽  
P Type ◽  
Non Destructive

Photoluminescence(PL)-topography is a powerful method to determine the charge carrier concentration of SiC-wafers. The following work describes the development of a PL-topography method for the determination of charge carrier distribution in p-type SiC and shows the correlation of PL-Intensity and charge carrier concentration. With this setup it is possible to characterize wafers up to a size of 2” at room- and low temperature in a non-destructive way.

The influence of composition on polymorphism, structure and charge carrier concentration in TL-2201.

1994 ◽  
Vol 235-240 ◽  
pp. 539-540
Author(s):  
C. Ström ◽  
S.-G. Eriksson ◽  
J. Albertsson ◽  
N. Winzek
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Charge Carrier Concentration

Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

2011 ◽  
Vol 121-126 ◽  
pp. 1526-1529
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Thermoelectric Properties ◽  
Impurity Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

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