Development of Organic Field-effect Transistors for Operation at High Frequency

To date, the majority of the works in scientific literature have paid limited attention to the alternating current (AC) behavior of carbon-based field-effect transistors (FETs). This chapter reviews how it is possible to address the high-frequency operation of organic semiconductor-based FETs (OFETs). It introduces the transition frequency, a commonly adopted figure of merit for the characterization of the maximum operational frequency of a transistor. The chapter illustrates how the operational performance of an OFET depends on the physical and geometrical parameters of the device. It describes the requirements that the materials, geometry, and design of a device must satisfy for the improvement of the AC performance and their mutual interplay. The chapter also describes how the achievement of such requirements has been approached so far in the field of organic electronics, reporting the most significant works aimed at high-frequency operation of OFETs.