ABSTRACT
This chapter provides fundamentals of organic transistors, including the device physics and the materials chemistry. It describes the recent progress in ambipolar materials, the use of organic metals, and the analysis of temperature-dependent transistor characteristics. The number of n-channel organic semiconductors is limited in comparison with p-channel materials, and many are operated only in vacuum. Recently, high-performance ambipolar transistors have been realized in polymers consisting of donor (D) and acceptor (A) parts. In order to reduce the contact resistance in bottom-contact transistors, a conducting polymer has been used as the electrode materials. Historically, analysis of temperature-dependent mobility in organic transistors dates back to Horowitz's work, in which the trap density of states (DOS) was obtained by analyzing temperature-dependent transfer characteristics. In addition to the practical applications, many physicists are interested in organic field-effect transistors in connection with graphene transistors and as a fundamental technique to realize quantum Hall effect.
