Organic field-effect transistors: from unipolar to ambipolar to light emission

In this contribution we emphasise the ambipolar organic field-effect transistors (OFETs) as the prime element for the realization of various OFET types. It will be shown that ambipolar OFETs can be used to produce on the one hand complementary unipolar OFETs and thus CMOS elements and on the other hand light-emitting OFETs. Some ambipolar light-emitting OFETs will be presented and the impact of the contact formation at the source and drain electrodes on the device characteristics will be discussed. In general, the investigation of ambipolar OFETs provides a deep understanding of the OFET operation and guides the way to novel aspects of the OFET applicability.