Air-stable, high-performance organic n-channel transistors

Organic thin-film transistors (TFTs) are of interest for flexible, large-area electronics applications, such as rollable or foldable information displays, conformable sensor arrays, and plastic circuits [1]. The vast majority of the organic TFTs that have been developed to date are p-channel TFTs, meaning that the electric currents in these transistors are due to the flow of positive charge carriers. Even if only p-channel TFTs were available, all types of electronic systems could in principle be realized, which would suggest that there is no fundamental reason to also develop organic n-channel TFTs (in which the currents are due to negative charge carriers). However, many of the applications envisioned for organic TFTs are mobile devices for which a low power consumption is one of the most critical requirements. From a circuit-design perspective, the most effective approach to minimize the power consumption of electronic systems is to combine p-channel and n-channel transistors in a complementary design. In complementary circuits, the current path between the supply-voltage rail and the ground rail is always blocked either by one of the p-channel transistors or by one of the nchannel transistors (except for a brief period during switching). In contrast, the power consumption of unipolar circuits (which use only one transistor type) is dominated by the existence of significant leakage paths not only during switching, but also whenever the circuit is in one of the two static states.