Organic field-effect transistor development

In the past decade, the research on organic field-effect transistors (OFETs) has experienced remarkable progress mainly because of the development of novel OFET materials, which have allowed to reach carrier mobility values good enough to compete with amorphous silicon. 

Presently there exists a strong research interest in the understanding, development, and optimisation of organic field effect transistors (OFETs) [1, 2]. Two classes of semiconducting organic materials are considered, namely molecular materials which are processed into thin films by vacuum sublimation [1, 2], and polymers which are deposited onto substrates in the form of solutions, for instance by spin coating [3]. In this chapter we report on OFETs based on thin polycrystalline films of the molecular material pentacene (Pc) as the semiconducting material. 

Novel oligomers based on P-substituted thiophene derivatives were synthesised with the aim to build-up a small molecule organic field-effect transistor (OFET). The developed material, a,o)-dicyano-P,P -dibutylquaterthiophene (DCNDBQT), exhibits exeellent thermal, optical and electrochemical stability. 

A new class of semiconductors for organic field-effect transistors (FET) has been developed and studied. Thus metalation of the 1,4-dibromobenzene derivative 141, followed by Introduction of the appropriate chalcogens gave the fused systems 142, which displayed promising FET performances, in particular the selenophene derivative <04JA5084>. 

The next significant milestone was the development of the first organic field effect transistor (OFET) with recognizable current gain by an in-situ pol mierized polythipohene transistor by Tsumura, Koezuka, and Ando of Mitsubishi Chemical in 1986 [2]. 

In the 1980s, research into organic field-effect transistors (OFETs) was initiated to investigate the characteristics of organic semiconductors, such as field-effect mobility [1]. In recent years, OFETs have been developed for novel... 

The metal-like property of these polymers is based on their chemical nature, which consists of chains of conjugated double bonds. If these polymers are oxidized, they become electrical conducting. In the neutral state they can have properties like an inorganic semiconductor. This has now become as important as the metal-like conductivity. One example is the development of an organic field effect transistor (OFET). 

The surface resistivity of PEDOT PSS patterned using flexo printing is rather high, ranging from a few to 10 kfl/n. However, new inks are continually developed, and improved performance is expected. PolylC is also developing a flexo production line for RFID tags based on organic field-effect transistors. 

K. Taldmiya, Y. Kimugi and T. Otsubo, Development of new semiconducting materials for durable high-performance air-stable organic field-effect transistors, Chem. Lett., 36, 578—583 (2007). 

There are many different types of bent-core molecules known, and most of exotic bent-core phase structures have been well elucidated. The future research and development on bent-core LCs shall be focused on the exploration of a variety of applications. Certainly, these applications shall not be limited to today s known bent-core molecules, and the development of new types of bent-core molecules incorporating varied functionalities based on new ideas or concepts is critically important. For instance, linking bent-core molecules with nanoscience and photoisomerization chemistry is a good step. Further exploration in organic field effect transistors (OFETs) and organic photovoltaics (OPVs) could be very fmitful. 

HC Starck is also involved in another significant development, the synthesis of poly(3,4-ethylenedioxythiophene) (PEDT) by in situ oxidative polymerisation or as a complex with polystyrene sulfonate as a template. There are a growing number of electrical and electronic applications for this material including antistatic coatings, capacitor cathodes, through-hole plating, OLED, organic field effect transistors, photovoltaics and electrochromics. 

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