Polymer polythiophenes

Polymers, large molecules made up of smaller molecules in a repeating pattern, are used for many electrochromic materials. Conjugating polymers, which have alternating single and double bonds, are particularly suitable. Figure B shows the electrochemical oxidation of the conjugated polymer, polythiophene. Oxidation (in which electrons are removed) produces a semiconductive polymer. The neutral (unoxidized) polythiophene is red in color, whereas the semiconductive polythiophene (oxidized) is blue. In their neutral... 

A particularly interesting fact is that in the case of a-sexithiophene, or a6T, work on prototype devices such as MISFETs has shown that thin films of a6T molecules actually exhibit better performance characteristics than the corresponding polymer, polythiophene, and rival those of amorphous silicon41. a6T also has been used in light emitting diodes42-44. 

The performance of OFETs has continuously improved since they were first reported in 1987 [8, 9]. The rate of the progress can be visualized in Figure 14-13, where we have plotted the field-effect mobility of five prominent organic com-pounds as a lunclion of the publication date. The data include one polymer, polythiophene and its derivatives and four small molecules (three oligothiophenes, plus pentacene). Note that the highest mobility of small molecules was reported on single crystals. 

Therefore, 10 years ago, the attention was turned towards the fascinating properties of conducting polymers polythiophene, polypyrrole and polyaniline (PANI) [7,8],... 

An electrochromic display (BCD) is a thin solid state device that changes color reversibly when subjected to a small electrical potential. Since the doping processes of certain conducting polymers are accompanied by changes in the color, this effect has been conveniently exploited in the realization of BCD devices. Thin films of a conducting polymer polythiophene, for example, are red in the doped state and deep blue in the undoped state. 

Kaneto, K., K. Yoshino, and Y. Inuishi. 1983. Characteristics of electro-optic device using conducting polymers, polythiophene and polypyrrole films. Jpn J Appl Phys 22 L412-L414. 

Cravino, A., G. Zerza, M. Maggini, S. Bucella, M. Svensson, M.R. Andersson, H. Neugebauer, C.J. Brabec, and N.S. Sariciftci. 2003. A soluble donor-acceptor double-cable polymer Polythiophene with pendant fiillerenes. Monatsh Chem 134 519-527. 

It is possible to prepare three typical ti-conjugated polymers, polythiophene, polypyrrole and polyaniline, by means of electrochemical oxidation of the corresponding monomers in the presence of an electrolyte at ambient temperature. In 1990, Canham discovered that photoluminescent porSi materials could be formed by an electrochemical method that used a p-type c-Si wafer. Electrochemical methods are among the safest, most environmentally friendly and technically favorable processes eompared to Na/Li-based Wurtz coupling reactions (Chart 13.10). ... 

Also the temperature of electropolymerization affects the extent of conjugation and hence the optical and electrical properties of the polymer. Polythiophene films produced at 40°C have been seen to display a shorter mean conjugation length than those prepared at 5°C [87,89-92,100]. 

Keywords Applications of conjugated polymers Polythiophene Thiophene as electron donor... 

Within the conjugated polymers polythiophene is an important material for future technical applications, e. g. for LEDs, electronic devices, or optical switches [1]. In this context studies of light induced processes are of interest, especially details of the degradation of electronic energy within the ultrashort time scale of picoseconds and sub-picoseconds. 

We have seen in this section that both S and 5 can be generated in relatively short trans chains. This indicates that short oligomers should not show completely different PM and ADMR spectra than their respective polymer films. In the next section we study an oligomer and its polymer counterpart of one important NDGS polymer, polythiophene (PT). Actually, since the PA bands of the oligomer are better defined than those of the polymer films, we discuss the PM spectroscopic results in the oligomer first, followed by the results in polythiophene. 

Keywords Field-effect transistor Mobility Morphology Poly (3-hexylthiophene) Polymer Polythiophene Transport... 

Conducting polymers Polythiophene Sensor/array of sensor based on block copoly-mers of poly thiophenes nanostructures fabri-cated through ink-jet printing on prefabricated electrode Ethanol 10 ppm fin all analytes i2-24... 

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