Ambipolar Transport in Organic Conjugated Materials

The relative mobility of holes versus electrons in π‐conjugated materials is a long‐standing issue in the field of organic electronics. In this Progress Report, we first argue on the basis of theoretical considerations that in general organic semiconductors are intrinsically as good electron transporters as they are hole transporters. Then, in the light of selected experimental works, we discuss the origin of the features that prevent the observation of intrinsic electron transport, and the strategies that have been developed to promote ambipolar transport in field‐effect transistors. Charge transport in organic semiconductors is discussed. Based on theoretical considerations, the mobility of electrons in organic semiconductors should not differ much from that of holes. Attention is given to the factors that hinder the observation of intrinsic electron transport, and to strategies that have been developed to promote ambipolar transport in field‐effect transistors (see figure).