High-performance Polythiophene Design

sufficiently long alkyl side-chains to provide solution processability  

structural regularity to enable molecular self-organization from solution deposition and 

proper control of -conjugation to achieve a balance between air stability and FET property. 

Of these design principles, the requirement for building stability against oxidative doping in a semiconductor structure without compromising its semiconductive properties is perhaps the most demanding. 

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Ong, B. Wu, Y. Liu, P. 2005. Design of high-performance regioregular polythiophenes for organic thin-film transistors. Proc. IEEE 93 1412-1419. 

Naito and co-workers used a thienothiophene linker to improve the relatively poor PL of the polythiophene in the solid state [59]. Such linkers are well known in the design of high-mobility PTs for field effect transistors and photovoltaics (see Chapter 17). The pl value of thiophene polymer 33 is close to that for regioregular P3HT (HT-9f) in solution (27 and 33 %, respectively), but is much higher in the solid state (16 and 0.3 %, respectively), which was ascribed to intrachain disorder of this less symmetric structure. Both PL in films and EL spectra of an ITO/33/A1 device showed emission at 580 nm, although no other characteristics of device performance was reported. 

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