Nachweis der Volumen-Ionisation in organischen Flüssigkeiten

1965 ◽  
Vol 20 (3) ◽  
pp. 394-400
Author(s):  
H. Bässler ◽  
P. Mayer ◽  
N. Riehl

In order to study the bulk-conductivity in organic liquids measurements with blocking quartzelectrodes were made. When applying a constant field, a bulk-current through the dielectric liquid can be observed, which is decreasing exponentiallyjd(t)=j0_ exp {—t/R_C}+j0 exp {—t/R+ C}.R- and R+ are the bulk-resistivities for negative and positive charge-carriers, from which the bulk-conductivity of the liquid can be calculated. It is identical with the dc.-conductivity measured with conducting electrodes, that is it obeys the law:σ=σ01 exp { —E1/k T} +σ02 exp {—E.2/k T}.Therefore the generation of charge-carriers must be independent of the electrodes and the activation-energies E1 and E2 must correlate with ionisation within the liquid. The mobility of negative carriers is about two or three times that of positive ones. This fact leads to conclusions concerning the nature of the carriers. A tunnel-process is proposed to explain the discharging of positive ions at a metallic cathode.

1964 ◽  
Vol 19 (9) ◽  
pp. 1070-1075
Author(s):  
H. Vogel ◽  
H. Bässler

The activation energy of the d. c. conductance of organic liquids lies between 0.04 and 0.45 eV in the lower region of temperature of their liquid state. A comparison of these values with the static dielectric constant shows, that the activation energy may be regarded as a pure COULOMB energy: E2 = e2/2 ε r . The characteristic distance r has the approximate value of 8.5 Å for hydrocarbons. It decreases for halogen- and nitro-derivates. Formerly it was found that the conductivity of mixtures obeys the law σM = σAC · σB1-C. This can easily be explained assuming εM = c εA + (1 — c) εB. In the case of rather different ε values or of homologuous compounds forming complexes, σ increases. This is identical with a kink in the log σ (c) -curve.


2021 ◽  
Author(s):  
Jiří Pavlů ◽  
Samuel Kočiščák ◽  
Åshild Fredriksen ◽  
Michael DeLuca ◽  
Zoltan Sternovsky

<p>We experimentally observe both positive and negative charge carriers in impact plasma and estimate their effective temperatures. The measurements are carried on a dust accelerator using polypyrrole (PPy)-coated olivine dust particles impacting tungsten (W) target in the velocity range of 2–18 km/s. We measure the retained impact charge as a function of applied bias potential to the control grid. The temperatures are estimated from the data fit. The estimated effective temperatures of the positive ions are approximately 7 eV and seems to be independent of the impact speed. The negative charge carriers' temperatures vary from as low as 1 eV for the lowest speeds to almost ten times higher speeds. The presented values differ significantly from previous studies using Fe dust particles. Yet, the discrepancy can be attributed to a larger fraction of negative ions in the impact plasma that likely originates from the PPy coating.</p>


1975 ◽  
Vol 6 (13) ◽  
Author(s):  
WERNER F. SCHMIDT ◽  
GEORGE BAKALE ◽  
ULRICH SOWADA

1974 ◽  
Vol 61 (12) ◽  
pp. 5275-5278 ◽  
Author(s):  
Werner F. Schmidt ◽  
George Bakale ◽  
Ulrich Sowada

2008 ◽  
Vol 1072 ◽  
Author(s):  
Semyon D. Savransky ◽  
Ilya V Karpov

ABSTRACTNew technique to separate bulk and interface electrical properties of polycrystalline and glassy Ge2Sb2Te5 (GST) in phase-change memory (PCM) devices is proposed. PCM with different GST thicknesses are measured. The average activation energies for bulk conductivity are 0.37 eV and 0.09 eV as well as bulk resistivities are about μOhm*cm2 and 20 μOhm*cm. The contact barriers is 0.07eV and specific contact resistance is about 0.3 μOhm*cm2 in studied PCM devices.It is discovered that bulk resistivities for both SET and RESET states in PCM obey Meyer-Neldel rule with almost identical isokinetic temperatures 335K − 340K. This information is discussed in terms of GST structure.


2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>


2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>


1976 ◽  
Vol 31 (10) ◽  
pp. 1313-1316
Author(s):  
Heinz P. Fritz ◽  
Dagmar Laschka

The electrical conductivity of polycrystalline pellets of ZnSO4 · 7 H2O, MgSO4 · 7 H2O, CuSO4 · 5 H2O, KAl(SO4)2 · 12 H2O, NH4Al(SO4)2 · 12 H2O and KCr(SO4)2 · 12 H2O was measured. By coulometry the role of protons as charge carriers was determined. A correlation is given between the strength of hydrogen bonds and the activation energies for the proton conductivity.


Sign in / Sign up

Export Citation Format

Share Document