Polymer field-effect transistors

Printable electronics is a key application area for conjugated polymers. Much emphasis is placed on developing a transistor that could be built merely from solutionprocessable materials, show stable electronic performance, and offer a sufficient lifetime for any chosen application. Conjugated polymers offer one of the most versatile material alternatives for printed transistors. Solubility in common solvents is an important advantage held by polymers compared with their molecular counterparts. Therefore, the focus of polymer transistors research is on devices that may be manufactured at low cost by solution processing, e.g., printing. The semiconductor layer is of specific relevance when transistors are developed, though the importance of the insulating and conducting materials should not be neglected. Furthermore, the interfaces between layers play an important role in device performance. Stability is one of the key issues when processing is scaled up both in device fabrication volumes and in circuit integration. This chapter gives a general introduction to polymer transistors. The basic operating principle for the devices and currently the most essential materials are discussed, and a future outlook with regard to processing and applications, in particular, are presented. The chapter should be read as a complement to Chapter 10 with a special emphasis on polymers, and should be regarded more as a review of the field.