ABSTRACT
This chapter gives an overview of the theoretical background
of polymer field-effect transistors (PFETs). It starts with the
description of the molecular and electronic structures and optical
transitions in conjugated polymers which are used as an active layer
of PFETs. The second part of the chapter focuses on the work-
ing principles of PFETs including metal-insulator-semiconductor
capacitors. Finally, several charge transport models developed for
polymer and organic field-effect transistors and a few recent
progress are discussed.