Electrical Transport in a Disordered Medium: NMR Measurement of Diffusivity and Electrical Mobility of Ionic Charge Carriers

1998 ◽  
Vol 135 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Stefan R. Heil ◽  
Manfred Holz
Keyword(s):  
Electrical Transport ◽  
Charge Carriers ◽  
Electrical Mobility ◽  
Ionic Charge ◽  
Disordered Medium

Composition-Dependent Electrical Conductivity of Ionic-Electronic Composite

1997 ◽  
Vol 500 ◽  
Author(s):  
M. Park ◽  
G. M. Choi
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Electromotive Force ◽  
Composition Dependence ◽  
Force Measurement ◽  
Ionic Transport ◽  
Charge Carriers ◽  
Stabilized Zirconia ◽  
Ionic Charge ◽  
Polarization Technique

ABSTRACTComposition. dependence of electrical conductivity of ionic-electronic composite was camined using yttria(8mol%) stabilized zirconia-NiO composites. The contributions of ectronic and ionic charge carriers to the electrical conductivity were determined by Hebb-Vagner polarization technique and electromotive force measurement of galvanic cell. Up to 6 sol% NiO addition, the conductivity decreased since the electronic NiO acted as an insulator in onic matrix. However the ionic transport was dominant until NiO content reaches 26 vol%. Mixed conduction was observed between 26 and 68 vol% of NiO. The effects of composition on he electrical properties were explained by the microstructure and thus by the distribution of two hases.

Buffer Layer Thickness and the Properties of InN Thin Films on AIN- Seeded (00.1) Sapphire And (111) Silicon

1994 ◽  
Vol 339 ◽  
Author(s):  
T. J. Kistenmacher ◽  
S. A. Ecelberger ◽  
W. A. Bryden
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Layer Thickness ◽  
Electrical Transport ◽  
Lattice Mismatch ◽  
Electrical Mobility ◽  
Seeded Growth ◽  
Electrical Transport Properties ◽  
Buffer Layer Thickness ◽  
Homogeneous Strain

ABSTRACTIntroduction of a buffer layer to facilitate heteroepitaxy in thin films of the Group IIIA nitrides has had a tremendous impact on growth morphology and electrical transport. While AIN- and self-seeded growth of GaN has captured the majority of attention, the use of AIN-buffered substrates for InN thin films has also had considerable success. Herein, the properties of InN thin films grown by reactive magnetron sputtering on AIN-buffered (00.1) sapphire and (111) silicon are presented and, in particular, the evolution of the structural and electrical transport properties as a function of buffer layer sputter time (corresponding to thicknesses from ∼50Å to ∼0.64 μm) described. Pertinent results include: (a) for the InN overlayer, structural coherence and homogeneous strain normal to the (00.1) growth plane are highly dependent on the thickness of the AIN-buffer layer; (b) the homogeneous strain in the AIN-buffer layer is virtually nonexistent from a thickness of 200Å (where a significant X-ray intensity for (00.2)AIN is observed); and (c) the n-type electrical mobility for films on AIN-nucleated (00.1) sapphire is independent of AIN-buffer layer thickness, owing to divergent variations in carrier concentration and film resistivity. These effects are in the main interpreted as arising from a competition between the lattice mismatch of the InN overlayer with the substrate and with the AIN-buffer layer.

Charge Transport Properties of a Partially Reduced V2O5 Xerogel Intercalated with a Polymer Electrolyte

1995 ◽  
Vol 393 ◽  
Author(s):  
Joyce Albritton Thomas ◽  
Grant M. Kloster ◽  
D. Shriver ◽  
C. R. Kannewurf
Keyword(s):  
Charge Transport ◽  
Transport Properties ◽  
Polymer Electrolyte ◽  
Variable Temperature ◽  
Sol Gel ◽  
Electronic Conductivity ◽  
Charge Carriers ◽  
Electronic Charge ◽  
Ionic Charge ◽  
Intimate Contact

ABSTRACTRecently, there has been considerable interest in advanced materials and processing techniques for practical applications. V2O5 xerogels have generated much attention because they are layered materials that undergo reversible redox intercalation with lithium. The sol-gel process has been used to intercalate V2O5 xerogels with the polymer electrolyte, oxymethylene linked poly(ethylene oxide) - lithium triflate [(a-PEO)n(LiCF3SO3)]. The resulting nanocomposite is a mixed ionic-electronic conductor in which the ionic charge carriers in the polymer electrolyte are in intimate contact with the electronic charge carriers in the V205 xerogel. Variable-temperature electronic conductivity and thermoelectric power measurements have been performed to examine the charge transport properties.

Morphology and Low Temperature Electrical Transport in Heteroepitaxial Indium Nitride Films

1992 ◽  
Vol 263 ◽  
Author(s):  
W. A. Bryden ◽  
S. A. Ecelberger ◽  
T. J. Kistenmacher
Keyword(s):  
Low Temperature ◽  
Temperature Dependence ◽  
Electrical Transport ◽  
Deposition Temperature ◽  
Amorphous Materials ◽  
Indium Nitride ◽  
Electrical Contact ◽  
Rf Magnetron Sputtering ◽  
Electrical Mobility ◽  
Reactive Rf Magnetron Sputtering

ABSTRACTThe correlation of low temperature electrical transport with the evolution of heteroepitaxy and morphology for sputtered indium nitride thin films has been studied. A series of indium nitride films were deposited at temperatures ranging from 50 -650 °C by reactive rf magnetron sputtering onto the (00.1) face of sapphire. Above 350 °C, a transition occurs from a continuous morphology, in which grains are in intimate electrical contact, to an open, porous morphology with poor electrical contact. This transition in morphology deeply affects the electrical transport of the semiconductor. At low deposition temperature, the electrical transport is dominated by the relatively weak intergrain scattering leading to films with moderate mobility. As the deposition temperature is raised, the increasingly porous nature of the film leads to a deterioration in electrical mobility. It is proposed here that the relevant physics of these films is analogous to that for granular solids with a distribution of electrical connectivities that suggests a scattering potential dominated by disorder. In fact, the temperature dependence of the resistivity is found to be analogous to that observed in disordered and amorphous materials. In particular, the resistivity is characterized by: 1) A very weak temperature dependence; 2) The observation of a resistance minimum; and, 3) A steep rise in the low temperature (<4K) resistivity that follows a T1/ dependence.

scholarly journals Synthesis of p -and n-type Gels Doped with Ionic Charge Carriers

2010 ◽  
Vol 5 (3) ◽  
pp. 559-565 ◽  
Author(s):  
E. Alveroglu ◽  
Y. Yilmaz
Keyword(s):  
Charge Carriers ◽  
Ionic Charge

INTERACTIONS OF THz VIBRATIONAL MODES WITH CHARGE CARRIERS IN DNA: POLARON-PHONON INTERACTIONS

2007 ◽  
Vol 17 (02) ◽  
pp. 293-309 ◽  
Author(s):  
DINAKAR RAMADURAI ◽  
TAKAYUKI YAMANAKA ◽  
YANG LI ◽  
MILANA VASUDEV ◽  
VISWANATH SANKAR ◽  
...  
Keyword(s):  
Charge Transport ◽  
Electrical Transport ◽  
Theoretical Calculations ◽  
Charge Trapping ◽  
Directed Assembly ◽  
Charge Carriers ◽  
Vibrational Modes ◽  
Electrical Transport Properties ◽  
One Dimensional ◽  
Phonon Absorption

This paper presents models and experimental measurements that shed light on THz-phonon mediated transport of polarons in biomolecules. Polaron transport in DNA has been considered recently in view of the expected derealization of charge carriers on a one-dimensional wire as well as the highly charged nature of DNA.1,2 An understanding of the electrical transport properties and THz-phonon interactions of biomolecules is important in view of DNA's potential applications both as electrically conductive wires and as structures that facilitate the chemically-directed assembly of massively integrated ensembles of nanoscale semiconducting elements into terascale integrated networks. Moreover, understanding these interactions provides information of the THz spectrum of vibrational modes in DNA. A primary focus of this paper is on charge transport in biomolecules using indirect-bandgap colloidal nanocrystals linked with biomolecules.3 Through a combination of theoretical and experimental approaches,4-7 this paper focuses on understanding the electrical properties and THz-frequency interactions of DNA. Moreover, this paper presents observed charge transport phenomena in DNA and discusses how these measurements are related to carrier scattering from the THz vibrational modes in DNA. Indeed, carrier transport in DNA is analyzed in light of theoretical calculations of the effects of THz-frequency phonon emission by propagating carriers, THz-frequency phonon absorption by propagating and trapped carriers, and effective mass calculations for specific sequences of the DNA bases.1-7 These studies focus on THz-phonon-mediated processes since an extra carrier on a one-dimensional chain minimizes its energy by forming an extended polaron, and since many biomolecules, including DNA, exhibit THz vibrational spectra.8 Accordingly, these calculations focus on THz-phonon-mediated processes. These results are discussed in terms of the role of THz-phonon-mediated charge trapping and detrapping effects near guanine-rich regions of the DNA as well as on the understanding and identification of DNA with specific base sequences that promote charge transport. As in previous studies, optical excitation is used to inject carriers into DNA wires. Moreover, this paper reports on the use of gel electrophoresis to study charge-induced cleavage of DNA and the related transport of charge in DNA. Phonon absorption and emission from polarons in DNA,9 is analyzed using parameters from the well-known Su-Schrieffer-Heeger Hamiltonian.

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