2D MXene–Molecular Hybrid Additive for High-Performance Ambipolar Polymer Field-Effect Transistors and Logic Gates

International audience; MXenes are highly conductive layered materials that are attracting a great interest for high-performance opto-electronics, photonics, and energy applications.. Their non-covalent functionalization with ad hoc molecules enables the production of stable inks of 2D flakes to be processed in thin-films. Here, the formation of stable dispersions via the intercalation of Ti3C2Tx with didecyldimethyl ammonium bromide (DDAB) yielding Ti3C2Tx–DDAB, is demonstrated. Such functionalization modulates the properties of Ti3C2Tx, as evidenced by a 0.47 eV decrease of the work function. It is also shown that DDAB is a powerful n-dopant capable of enhancing electron mobility in conjugated polymers and 2D materials. When Ti3C2Tx–DDAB is blended with poly(diketopyrrolopyrrole-co-selenophene) [(PDPP–Se)], a simultaneous increase by 170% and 152% of the hole and electron field-effect mobilities, respectively, is observed, compared to the neat conjugated polymer, with values reaching 2.0 cm2 V−1 s−1. By exploiting the balanced ambipolar transport of the Ti3C2Tx–DDAB/PDPP–Se hybrid, complementary metal–oxide–semiconductor (CMOS) logic gates are fabricated that display well-centered trip points and good noise margin (64.6% for inverter). The results demonstrate that intercalant engineering represents an efficient strategy to tune the electronic properties of Ti3C2Tx yielding functionalized MXenes for polymer transistors with unprecedented performances and functions.