Field polythiophene

In 1979, the formation of conductive polypyrrole films by the electrochemical oxidation of pyrrole was reported for the first time This work has stimulated intense and fruitful research in the field of organic conducting polymers. Further important conductive polymers are polythiophene, polyaniline and polyparaphenylene. The development and technological aspects of this expanding research area is covered... 

Bao, Z. Lovinger, A. 1999. Soluble regioregular polythiophene derivatives as semiconducting materials for thin film field-effect transistors. Chem. Mater. 11 2607-2612. 

Polythiophenes (PTs)/CNTs composites have emerged as an intriguing system for use as photovoltaic devices and field effect transistors [57]. Swager and Bao independently reported methods for the assembling of PTs/CNTs systems and showed their great potential as transparent conductive films [58]. Another interesting application arises from the possibility to functionalize the polythiophene backbone for applications as chemical sensors [134]. 

Heterojunctions of polythiophene with polypyrrole [195] and Cds [196] of the Schottky type were constructed and tested. The height of the barrier was 0.8 eV. The photogeneration of the charge carrier takes place in the depletion layer of the thiophene with consequent separation in the barrier electric field. 

A polyacetylene field-effect transistor has been described622 but the response time is slow, apparently because the carrier mobility is low. An FET has been made from polythiophene but source-drain currents were less than 20 nA for drain voltages up to 50 V. The hole mobility was very low, calculated to be 2 x 10 5 cm2 V-1 s 1 623). 

An extensive review of the synthesis of rc-conjugated polymers is presented using a tutorial approach to provide an introduction to the field intended for the undergraduate student and the experienced chemist alike. The many synthetic methodologies that have been used for the synthesis of conjugated polymers are outlined for each class of polymers with a focus on research from the 1990s. The effect of structure on electrical properties is detailed. Specific systems reviewed include the polyacetylenes, polyanilines, polypyrroles, polythiophenes, poly(arylene vinylenes), and polyphenylenes. 

It was shown earlier that the efficiency of the diode depends significantly on the thicknesses of the layers due to the optical field distribution inside the device, caused by the interference of the incoming light with light reflected from the mirror cathode. The blend diode is always more efficient than the neat diode. The excitation created by absorption in the PPV phase is transferred to the polythiophene, where a more efficient charge separation process is possible, as is clear from Figs. 6.10 and 6.11. 

Mechanically durable and structurally flexible polythiophene derivatives have been prepared that are useful as semiconducters in thin film field effect transistors and are soluble in chlorobenzene. Materials prepared from these agents have a bandgap between 1.5 and 3.0 eV that enhance their function as film transistors. 

Regioregular intriniscally conducting mono-, di-, and triblock moderate molecular weight polythiophenes containing a well-defined terminus, (Vlll), were prepared by McCullough [7] and used in thin field-effect transitor applications. 

---