Recent Efforts in Understanding and Improving the Nonideal Behaviors of Organic Field-Effect Transistors

Over the past three decades, the mobility of organic field-effect transistors (OFETs) has been improved from 10^-5 up to over 10 cm² V^-1 s^-1, which reaches or has already satisfied the requirements of demanding applications. However, pronounced nonideal behaviors in current-voltage characteristics are commonly observed, which indicates that the reported mobilities may not truly reflect the device properties. Herein, a comprehensive understanding of the origins of several observed nonidealities (downward, upward, double-slope, superlinear, and humped transfer characteristics) is summarized, and how to extract comparatively reliable mobilities from nonideal behaviors in OFETs is discussed. Combining an overview of the ideal and state-of-the-art OFETs, considerable possible approaches are also provided for future OFETs.