Noncovalent semiconducting polymer monolayers for high-performance field-effect transistors

In recent years, noncovalently assembled monolayers of conjugated, semiconducting polymers with thickness less than 5 nm have attracted increasing attention because of their determining role in charge carrier transport in field-effect transistors and their multifunctionality in other electronic devices. This article reviews recent advances in various promising and cutting-edge polymer monolayers for high-performance field-effect transistors with the main focuses on: (I) solution processing techniques for long-range ordering; (II) the importance of polymer aggregation in solution; (III) the effect of polymer packing orientation; (IV) engineering of the interface between the polymer monolayer with electrodes and dielectrics; (V) investigating the mechanism of charge carrier transport. By summarizing the field-effect mobilities of the different classes of conjugated semiconducting polymer monolayers, further understanding of correlation between monolayer structure and device property will be revealed. Furthermore, we also highlight the recent progress of other electronic applications of polymer monolayers such as integrated circuits, chemical sensors, and light-emitting diodes. Finally, we propose future research opportunities and remaining challenges in this exciting research field.