scholarly journals Controlled/living polymerization towards functional poly(p-phenylene vinylene) materials

2016 ◽  
Vol 7 (7) ◽  
pp. 1355-1367 ◽  
Author(s):  
N. Zaquen ◽  
L. Lutsen ◽  
D. Vanderzande ◽  
T. Junkers
Keyword(s):  
Living Polymerization ◽  
Semiconductor Materials ◽  
Phenylene Vinylene ◽  
Important Class ◽  
Polymeric Semiconductor

Poly(p-phenylene vinylene)s (PPVs) are an important class of highly fluorescent polymeric semiconductor materials.

Time-of-Flight Technique Limits of Applicability for Thin-Films of Π-Conjugated Polymers

2012 ◽  
Vol 1402 ◽  
Author(s):  
Marco R. Cavallari ◽  
Vinicius R. Zanchin ◽  
Cleber A. Amorim ◽  
Gerson dos Santos ◽  
Fernando J. Fonseca ◽  
...  
Keyword(s):  
Thin Films ◽  
Conjugated Polymers ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Time Of Flight ◽  
Hole Mobility ◽  
Current Mode ◽  
Phenylene Vinylene ◽  
Polymeric Semiconductor ◽  
Order Of Magnitude

ABSTRACTTime of flight (ToF) is the most straightforward technique to determine polymeric semiconductor mobility for electronic applications. We demonstrate ToF limits of applicability to amorphous PPV derivatives, such as poly[2-methoxy-5-(3’,7’-dimethylloctyloxy)-1-4-phenylene vinylene] (MDMO-PPV) and poly[2-methoxy-5-(2’-ethylhexyloxy)-1-4-phenylene vinylene] (MEH-PPV), and polycrystalline poly(3-hexylthiophene) (P3HT). Hole and electron mobility (μ) in submicrometric films (200 – 500 nm) is overestimated compared to casted layers, due to reduced absorption capability, which is confirmed by Charge Extraction by Linearly Increasing Voltage (CELIV) measurements. Charge transport properties in nanometric films, such as for Field-Effect Transistors (FET), can not be studied by current-mode ToF. Hole mobility of ca. 10-5 cm2/Vs with Poole-Frenkel behavior for PPV derivatives and 10-3 cm2/Vs for P3HT is at least one order of magnitude higher than ToF results.

Electrical Transient Based Defect Spectroscopy in Polymeric and Organic Semiconductors

2005 ◽  
Vol 864 ◽  
Author(s):  
Y.N. Mohapatra ◽  
V. Varshney ◽  
V. Rao ◽  
Samarendra P. Singh ◽  
G.S. Samal
Keyword(s):  
Organic Semiconductors ◽  
Time Domain ◽  
Semiconductor Materials ◽  
Time Constants ◽  
Polymeric Semiconductor ◽  
Organic Diodes ◽  
Transient Spectroscopy ◽  
Stretched Exponentials ◽  
Current Transients ◽  
Large Distribution

AbstractThe relation between electrically active defects in organic and polymeric semiconductor materials and degradation of devices such as loss of luminance is currently not understood. In this paper, we study defect related charge processes using electrical transients in polymeric and organic diodes. We monitor slow charging and discharging currents as a function of time for both virgin and electrically aged devices. The current transients are analyzed spectroscopically in time domain using a technique called Time Analyzed Transient Spectroscopy, which is similar to DLTS in its implementation. We observe highly stretched exponentials over 3—4 orders of magnitude in time up to thousands of seconds indicating existence of large distribution in time constants in aged PLED devices. We demonstrate ability to distinguish between different mechanisms of charge storage related to defect related processes in typical OLED and PLED.

Controllable Binary/Ternary Memory Behavior Induced by Isomerization of Phenylhydrazone Groups in Polymer Side Chains under Ultraviolet Light Condition

2021 ◽  
Author(s):  
Jian-Mei Lu ◽  
Guan Wang ◽  
Qijian Zhang ◽  
Fengjuan Zhu ◽  
Cheng Zhang ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Light Condition ◽  
Light Energy ◽  
Semiconductor Materials ◽  
Side Chains ◽  
Common Phenomenon ◽  
Polymeric Semiconductor

The damage of ultraviolet light to organic/polymeric semiconductor materials is a common phenomenon, so it becomes very important to construct a mechanism to dissipate the ultraviolet light energy by internal...

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Gold liposomes

1996 ◽  
Vol 54 ◽  
pp. 898-899
Author(s):  
James F. Hainfeld
Keyword(s):  
Direct Methods ◽  
Important Class ◽  
Double Bonds ◽  
Membrane Phospholipids ◽  
Essential Ingredient ◽  
Lipid Structures

Lipids are an important class of molecules, being found in membranes, HDL, LDL, and other natural structures, serving essential roles in structure and with varied functions such as compartmentalization and transport. Synthetic liposomes are also widely used as delivery and release vehicles for drugs, cosmetics, and other chemicals; soap is made from lipids. Lipids may form bilayer or multilammellar vesicles, micelles, sheets, tubes, and other structures. Lipid molecules may be linked to proteins, carbohydrates, or other moieties. EM study of this essential ingredient of life has lagged, due to lack of direct methods to visualize lipids without extensive alteration. OsO4 reacts with double bonds in membrane phospholipids, forming crossbridges. This has been the method of choice to both fix and stain membranes, thus far. An earlier work described the use of tungstate clusters (W11) attached to lipid moieties to form lipid structures and lipid probes.

Deriving ultrapure three-dimensional semiconductor materials under space vacuum conditions

2003 ◽  
Vol 8 (5-6) ◽  
pp. 30-32
Author(s):  
B.E. Paton ◽  
◽  
E.A. Asnis ◽  
S.P. Zabolotin ◽  
P.I. Baranskii ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Semiconductor Materials ◽  
Space Vacuum
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