Electronic Transport in Organic Materials: Comparison of Band Theory with Percolation/(Variable Range) Hopping Theory

2011 ◽  
Vol 23 (30) ◽  
pp. 3356-3362 ◽  
Author(s):  
P. Stallinga
Keyword(s):  
Electronic Transport ◽  
Organic Materials ◽  
Variable Range Hopping ◽  
Band Theory ◽  
Variable Range

Path to Strong Insulating Transport Properties in Bulk AlPdRe Samples

2003 ◽  
Vol 805 ◽  
Author(s):  
Ralph Rosenbaum ◽  
Yuan-Liang Zhong ◽  
Juhn-Jong Lina
Keyword(s):  
Simple Model ◽  
Magnetic Fields ◽  
Transport Properties ◽  
Electronic Transport ◽  
Power Laws ◽  
Zero Field ◽  
Variable Range Hopping ◽  
Inverse Temperature ◽  
Variable Range ◽  
Transport Measurements

ABSTRACTElectronic transport measurements have been made on bulk icosahedral Al70Pd22.5Re7.5 quasicrystal (QC's) samples, having increasingly larger resistance temperature ratios, rT = R(4.2 K)/R(292 K). Data were taken between 0.023 K to 292 K and in magnetic fields up to 17.9 T. Both the zero field resistivity and the magnetoresistance (MR) changed from metallic behavior to weakly insulating behavior to highly insulating behavior, as the resistance temperature ratios rT's of the samples were made larger. For the insulating samples, the resistivities ρ's followed simple inverse temperature power laws above 50 K going as ρ(T) = a0/Tz, where z = 1 ± 0.1.The insulating QC samples exhibited saturation behaviors of their resistivities below 2 K. Below 0.3 K, the strongly insulating QC's displayed activated variable-range hopping (VRH) laws in their conductivity; the hopping exponents y's in the VRH laws varied between 0.19 ≤ y ≤ 0.43. A simple model including conductivity contributions both from the primary insulating QC phase and from a secondary metallic phase yielded good fits to the resistivity and MR data.

Electronic transport mechanism in polydiacetylene crystals — variable range hopping or phonon-assisted tunnelling

Open Physics ◽  
2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Povilas Pipinys ◽  
Antanas Kiveris
Keyword(s):  
Electronic Transport ◽  
Transport Mechanism ◽  
Rate Dependence ◽  
Experimental Results ◽  
Variable Range Hopping ◽  
Temperature Dependent ◽  
Variable Range ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
High And Low Temperatures

AbstractExperimental results on the current-voltage characteristics of polydiacetylene (PDA) single crystals reported by Aleshin et al [Phys. Rev. Vol. B 69, (2004) art. 214203] are reinterpreted in terms of the phonon-assisted electron tunnelling model. It is shown that the experimental results, measured in the temperature range from 1.8 K to 300 K are consistent with the tunnelling rate dependence on field strength, computed for the same range of temperatures. An advantage of this model over that of Aleshin et al, using the variable range hopping (VRH) model, is the possibility of describing the behaviour of I — V data measured at both high and low temperatures with the same set of parameters characterizing this material. This assertion is confirmed by comparison of the temperature-dependent current-voltage data extracted from Aleshin et al’s work with tunnelling rate dependence on temperature, computed using two different expressions of the phonon-assisted tunnelling theory. The temperature dependence of the conductivity of an ion implanted PDA crystals [B. S. Elman et al, Appl. Phys. Lett., Vol. 46, (1985) p. 100] and polypyrrole [P. Dutta et al, Synth. Met., Vol. 139 (2003) p. 201] are also explained on the basis of this model.

Variable range hopping and/or phonon-assisted tunneling mechanism of electronic transport in polymers and carbon nanotubes

Open Physics ◽  
2012 ◽  
Vol 10 (2) ◽  
Author(s):  
Povilas Pipinys ◽  
Antanas Kiveris
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Transport ◽  
Graphene Nanoribbons ◽  
Variable Range Hopping ◽  
Variable Range ◽  
Tunneling Mechanism ◽  
Temperature Dependence Of Conductivity ◽  
Temperature Dependences ◽  
Assisted Tunneling ◽  
The One

AbstractWe review and compare two models recently used to describe electronic transport in polymer fibers/nanotubes and carbon nanotubes including graphene nanoribbons, namely, variable range hopping (VRH) in different versions and their modifications on the one hand and electric-field-induced phonon-assisted tunneling (PhAT) on the other hand. The VRH model is mainly approved on behalf of the results of temperature dependences. However, the field dependencies of the conductivity in the framework of this model remain practically unexplained. At the same time, the PhAT model describes properly not only temperature dependence of conductivity measured in a wide temperature range, but also conductivity/current dependences on field strength using the same set of parameters characterizing the materials

scholarly journals Efros–Shklovskii hopping in the electronic transport in 2D p-GaAs

2020 ◽  
Vol 60 (3) ◽  
Author(s):  
Said Dlimi ◽  
Lhoussine Limouny ◽  
Jamal Hemine ◽  
Adil Echchelh ◽  
Abdelhamid El kaaouachi
Keyword(s):  
Magnetic Field ◽  
Electronic Transport ◽  
Zero Magnetic Field ◽  
Variable Range Hopping ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Coulomb Gap ◽  
Variable Range ◽  
Temperature Range ◽  
Hole Interaction

We have investigated the resistivity of a 2D hole system in GaAs in the temperature range 200 mK < T < 800 mK at zero magnetic field and low hole densities when the system is near the metal–insulator transition in the insulating side. We have found that the resistivity follows the Efros–Shklovskii variable range hopping (ES-VRH) law, this behaviour is consistent with the existence of a Coulomb gap. The resistivity scales with temperature and the prefactor has been found independent of temperature and density, thus confirming the dominance of hole–hole interaction.

Mott variable range hopping transport in thermal evaporated vanadyl 2, 3 naphthalocyanine thin films

2021 ◽  
pp. 125029
Author(s):  
I. Dhanya ◽  
Malathy Krishnan ◽  
Reny Renji ◽  
M.K. Anu ◽  
Rachel G. Varghese ◽  
...  
Keyword(s):  
Thin Films ◽  
Variable Range Hopping ◽  
Hopping Transport ◽  
Variable Range
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