Spectroscopic Mapping Ellipsometry of Graphene Grown on 3C SiC

2012 ◽  
Vol 1407 ◽  
Author(s):  
Alexander Boosalis ◽  
Tino Hofmann ◽  
Vanya Darakchieva ◽  
Rositza Yakimova ◽  
Tom Tiwald ◽  
...  
Keyword(s):  
Free Charge Carrier ◽  
Visible Spectrum ◽  
Charge Carriers ◽  
Physical Parameters ◽  
Free Charge ◽  
Carrier Scattering ◽  
Scattering Time ◽  
Charge Carrier Scattering ◽  
Lateral Variations

ABSTRACTSpectroscopic mapping ellipsometry measurements in the visible spectrum (1.25 to 5.35 eV) are performed to determine the lateral variations of epitaxial graphene properties as grown on 3C SiC. Data taken in the visible spectrum is sensitive to both the Drude absorption of free charge carriers and the characteristic exciton enhanced van Hove singularity at 5 eV. Subsequent analysis with simple oscillator models allows the determination of physical parameters such as free charge carrier scattering time and local graphene thickness with a lateral resolution of 50 microns.

SFGP 2007 - Photosensitive Composite Disordered Nanostructures over Acceptor Supports: Selective Free Charge Carrier Generators for Environmental Applications

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Cristain Chis ◽  
Alexis Evstratov
Keyword(s):  
Charge Carrier ◽  
Free Charge Carrier ◽  
Charge Carriers ◽  
Environmental Applications ◽  
Free Charge ◽  
Active Components ◽  
Active Materials ◽  
Photocatalytic Removal ◽  
Volatile Organic

Amorphous and low-ordered photosensitive materials are not usually considered to be promising photocatalytic agents because of extremely short free charge carrier (FCC) lifetimes in their active components deprived of well-defined electronic structures. Using active supports favoring an efficient FCC separation in situ, it is possible to protect free charge carriers from the immediate recombination, so even the disordered photosensitive composites can be provided with important photocatalytic capacities. The examples of some environmental applications of this type of active materials, such as volatile organic compound (VOC) photocatalytic removal and bacteria sterilization, are presented in this paper.

scholarly journals Scattering Mechanisms in pressed PbTe

2020 ◽  
Vol 21 (1) ◽  
pp. 82-88
Author(s):  
O. M. Matkivsky ◽  
Ya. P. Saliy ◽  
I. V. Horichok
Keyword(s):  
Seebeck Coefficient ◽  
Theoretical Calculation ◽  
Thermoelectric Properties ◽  
Specific Conductivity ◽  
Charge Carriers ◽  
Free Charge ◽  
Pressing Method ◽  
Scattering Mechanisms ◽  
Carrier Scattering ◽  
Powder Pressing

The results of studies of structural and thermoelectric properties obtained by the powder pressing method of PbTe samples are presented. In order to interpret the obtained results, a theoretical calculation of the specific conductivity and the Seebeck coefficient was performed on the basis of a model that takes into account two types of free charge carriers. Conclusions have been made about the mechanisms of carrier scattering.

Calculation of Carrier Scattering and Negative Magnetoresistance in Mn-Doped GaAs/InGaAs/GaAs Quantum Well with Ferromagnetism

2009 ◽  
Vol 152-153 ◽  
pp. 283-286 ◽  
Author(s):  
V.A. Kulbachinskii ◽  
L. Shchurova
Keyword(s):  
Quantum Well ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Charge Carriers ◽  
Negative Magnetoresistance ◽  
Free Charge ◽  
Carrier Scattering ◽  
Diluted Magnetic ◽  
Mn Doped ◽  
The Magnetic Field

We have investigated the thermodynamic, transport and magnetotransport properties of free charge carriers in a diluted magnetic semiconductor with a quantum well InGaAs in the GaAs with δ-doped by C and Mn. In order to determine the density of the holes in a quantum well, we carried out thermodynamic calculations of the system of free holes, atoms Mn0 and ions Mn–. We calculated the temperature dependence of resistance and magnetoresistance of holes in the quantum well. The contributions of various scattering mechanisms of holes to the resistance were analyzed. The negative magnetoresistance are explained as the reduction of spin-flip scattering by aligning spins of the magnetic field.

Method for Determining the Doping Efficiency of Dispersed Semiconductor Metal Oxide Materials

2016 ◽  
Vol 683 ◽  
pp. 389-394
Author(s):  
Tatyana D. Malinovskaya ◽  
Victor I. Sachkov ◽  
Valentina V. Zhek ◽  
Roman A. Nefedov
Keyword(s):  
Metal Oxide ◽  
Free Charge Carrier ◽  
Charge Carrier Concentration ◽  
Charge Carriers ◽  
Oxide Materials ◽  
Free Charge ◽  
Technological Factors ◽  
Doping Impurity ◽  
Lower Solubility ◽  
Semiconductor Metal Oxide

In this paper, a method for determining the doping efficiency of dispersed semiconductor metal oxide materials is proposed proposing to use the dependences of the free charge carrier concentration, normalized to the concentration of the doping impurity (Ne spec.), on the content of this impurity. The possibilities of this method are demonstrated by the example of studying the effect of technological factors on the efficiency of doping of indium oxide with tin and doping of tin oxide with antimony. It is shown that it is impossible to achieve the concentration of free charge carriers in the ITO material, higher than that in ATO materials, due to the lower solubility of tin in the In2O3 lattice, as compared with the solubility of antimony in the SnO2 lattice.

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