OFET Studies

The meso-functionalized bis(thien-2-yl)methanes 267 (X=S) and bis(furan-2-yl)methanes 267 (X=0) were used for synthesizing the first neutral meso-functionalized tetrathia[22]annulene derivatives 271 (X=S) and tetraoxa[22]annulene derivatives 271 (X=0) (Scheme 105). The compounds were tested for organic field effect transistor (OFET) studies and have shown good mobilities with p-type semiconductor behavior (11JCS(CC)905,12JCS(CC)121). 

The field known as organic or plastic electronics is centered on organic field-effect transistor (OFET)-based circuits mounted on large-area and/or flexible mechanical supports. Work on OFETs has been extensively reviewed, and readers are referred to Materials Today, Chemistry of Materials, and Journal of Materials Research special issues [1-4]. A general goal of OFET studies is to provide some degree of silicon-like functionality at a small fraction of... 

This section is divided in two parts. In the first one, we review the studies on the transport mechanism in materials used in OFETs, whereby temperature-depen-dent measurements are a very powerful tool. The study of the gate bias dependence has also been used by researchers. In the second part, we present the few analytical models of the organic FETs that have been developed until now. 

Due to the great potential applications and the widespread interests of OFETs, several review articles with emphasis on different aspects of OFETs have been published [8-13], However, despite the extensive studies and increasing research interests in phthalocyanine as well as porphyrin semiconductors, there is still no review article that systematically generalizes the research achievements in the field of tetrapyrrole organic semiconductors for OFETs. Thus, the present contribution should interest scientists in both industrial and theoretical fields. The main contents of this chapter is as follows Firstly, some basic introduction of the structure and characteristics of OFET is provided then theoretical factors that influence the performance of OFET devices is discussed finally, the progress in phthalocyanine-based OFETs in the order of p-type, n-type, and ambipolar semiconductors is summarized. 

In comparison with MOEP and H2TPP, the increased planarity and tt conjugate system associated with the attached benzene rings on the pyrroles of porphyrin core render tetrabenzoporphyrins (TBPs) the most widely studied molecules among porphyrin derivatives for OFET devices. In 2004, Ono and co-workers... 

In order to co-polymerize the IC unit, Suzuki and Stille polymerizations have been used. First, Blouin et al. [94] were able to obtain polyindolo[3,2-fr]-carbazole derivatives with bithiophene or biEDOT as co-monomers. Unfortunately, these studies demonstrated a relatively low oxidation potential for these polymers (especially for P35 and P37), limiting their applications in OFETs and PCs. However, for doped state applications, these polymers may exhibit interesting properties [35]. For instance, when copolymerized with bithiophene, the resulting copolymer shows a good electrical conductivity (as high as 0.7 Scm 1) but a low Seebeck coefficient of 4.3 iV K 1 [35]. Finally, the UV-Vis absorption maxima are similar for poly(2,8-indolocarbazole-a/f-bithiophene) and poly(2,8-indolocarbazole-a/f-bis(3,4-ethylenedioxythiophene)). A broad absorption band is centered at 430 nm whereas, for the 3- and 9-substituted copolymers, the broad band is centered around 490-500 nm [94],... 

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