Electronic and Ionic Transports for Negative Charge Carriers in Smectic Liquid Crystalline Photoconductor

2005 ◽  
Vol 109 (47) ◽  
pp. 22120-22125 ◽  
Author(s):  
Hiroaki Iino ◽  
Jun-ichi Hanna
Keyword(s):  
Liquid Crystalline ◽  
Negative Charge ◽  
Charge Carriers

Charge carrier lifetimes in a smectic liquid crystalline photoconductor of a 2-phenylnaphthalene derivative

2003 ◽  
Vol 771 ◽  
Author(s):  
Hiroaki Iino ◽  
Jun-Ichi Hanna
Keyword(s):  
Charge Carrier ◽  
Liquid Crystalline ◽  
Negative Charge ◽  
Ionic Conduction ◽  
Time Of Flight ◽  
Charge Carriers ◽  
The Other ◽  
Time Range ◽  
Electron Lifetime ◽  
Carrier Lifetimes

AbstractWe have investigated the charge carrier lifetimes for electrons and holes in smectic mesophases of a 2-phenylnaphthalene derivative, 6-(4'-octylphenyl)-2-dodecyloxynaphthalene (8-PNP-O12) by time-of-flight (TOF) measurement. For the negative charge carriers, we found two transits in different time range, which are attributed to electronic and ionic conduction. With the aid of liquid-like fluidity of the material, we could prepare very thick samples over 500μm, and it enables us to determine the carrier lifetimes, which are governed by different regimes: the hole lifetime is governed by recombination of charge carriers and estimated to be 10-2 sec; on the other hand, the electron lifetime is dominated by trapping at deep states and estimated to be on the order of 10-5 sec for both SmA and SmB phases.

The Effective Temperature of Dust Impact Plasmas — Olivine Dust on Tungsten Target

2021 ◽  
Author(s):  
Jiří Pavlů ◽  
Samuel Kočiščák ◽  
Åshild Fredriksen ◽  
Michael DeLuca ◽  
Zoltan Sternovsky
Keyword(s):  
Negative Charge ◽  
Negative Ions ◽  
Charge Carriers ◽  
Dust Particles ◽  
Applied Bias ◽  
Control Grid ◽  
Impact Speed ◽  
Positive Ions ◽  
Effective Temperatures ◽  
The Impact

<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>

Electronic Functions in Liquid-Crystalline Nanostructures with High Polarization

MRS Advances ◽  
2019 ◽  
Vol 4 (31-32) ◽  
pp. 1733-1740
Author(s):  
Masahiro Funahashi
Keyword(s):  
Liquid Crystalline ◽  
Carrier Transport ◽  
Ferroelectric Phase ◽  
Photovoltaic Effect ◽  
Charge Carriers ◽  
Side Chain ◽  
Electronic Charge ◽  
Internal Electric Field ◽  
Alkyl Side Chain ◽  
Perylene Bisimide

AbstractMultifunctionality was created by coupling an electronic charge carrier transport with ionic conductivity or ferroelectricity in polarized liquid crystal phases. Liquid-crystalline perylene bisimide derivatives bearing cyclotetrasiloxane rings and triethylene oxide chains formed nanosegregated columnar structures which could conduct ions as well as electrons. The spin-coated thin films could be insolubilized by the exposure on acid vapors and display electrochromism. Phenylterthiophene derivatives bearing a chiral alkyl side chain exhibited a ferroelectric phase, in which a photovoltaic effect was caused by the interaction between photogenerated charge carriers with the internal electric field formed by the spontaneous polarization of the ferroelectric phase.

scholarly journals Dynamic assembly of liquid crystalline graphene oxide gel fibers for ion transport

2018 ◽  
Vol 4 (11) ◽  
pp. eaau2104 ◽  
Author(s):  
H. Park ◽  
K. H. Lee ◽  
Y. B. Kim ◽  
S. B. Ambade ◽  
S. H. Noh ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Liquid Crystalline ◽  
Colloidal Dispersions ◽  
Charge Carriers ◽  
Wet Spinning ◽  
Great Promise ◽  
Orientation Factor ◽  
Liquid Crystallinity ◽  
Spinning Process ◽  
Dynamic Assembly

Colloidal dispersions with liquid crystallinity hold great promise for fabricating their superstructures. As an example, when graphene oxide (GO) sheets are assembled in the liquid crystalline state, they can turn into ordered macroscopic forms of GO such as fibers via the wet spinning process. Here, we report that by reinforcing intersheet interactions, GO liquid crystals (LCs) turn into mechanically robust hydrogels that can be readily drawn into highly aligned fibrillar structures. GO hydrogel fibers with highly aligned sheets (orientation factor, f = 0.71) exhibit more than twice the ionic conductivity compared to those with partially aligned structures (f = 0.01). The hierarchically interconnected two-dimensional nanochannels within these neatly aligned GOLC hydrogel fibers may facilitate controlled transport of charge carriers and could be potentially explored as cables for interconnecting biosystems and/or human-made devices.

Negative charge carriers in the 90 K plateau of REBa2Cu3O7−δ

1995 ◽  
Vol 244 (1-2) ◽  
pp. 54-62 ◽  
Author(s):  
T. Plackowski ◽  
D. Włosewicz ◽  
C. Sułkowski ◽  
K. Rogacki
Keyword(s):  
Negative Charge ◽  
Charge Carriers

Effect of salts on the formation and properties of microcrystalline cellulose and chitosan gels 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Marianna Laka ◽  
Svetlana Chernyavskaya
Keyword(s):  
Microcrystalline Cellulose ◽  
Liquid Crystalline ◽  
Negative Charge ◽  
Raw Materials ◽  
High Concentration ◽  
Microcrystalline Chitosan ◽  
Amine Groups ◽  
The Difference ◽  
Dispersion Solution ◽  
Cellulose Surface

Abstract The difference in the effect of salts on the formation and properties of gels based on microcrystalline cellulose (MCC) and microcrystalline chitosan (MCCh) was investigated. Bleached sulphate pulp from wood and chitosan obtained from exoskeletons of crustaceans served as raw materials. These were destructed by a thermocatalytic method to the levelling-off degree of polymerisation and then dispersed in solutions of different salts. At a sufficiently high concentration, gels with a liquid crystalline structure were formed. For MCC, the gels are stronger when the dispersion solution contains polyvalent cations, which decrease the negative charge on the cellulose surface caused by the carboxyl groups present there. As a result, the mutual repulsing forces between the cellulose particles decrease and the lattice formed by them becomes stronger. For MCCh, strong gels with a great viscosity are formed when the dispersion solution contains polyvalent anions, which decrease the positive charge on the chitosan surface caused by amine groups. The effect of salts depends also on their concentration in the solution.

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