Highly Efficient Thin-Film Transistor via Cross-Linking of 1T Edge Functional 2H Molybdenum Disulfides

Abstract

Thin-film transistors (TFTs) have received great attention for their use in lightweight, large area, and wearable devices. However, low crystalline materials and inhomogeneous film formation limit the realization of high-quality electrical properties for channels in commercial TFTs, especially for flexible electronics. Here, we report a field-effect TFT fabricated via cross-linking of edge-1T basal-2H MoS2 sheets that are prepared by edge functional exfoliation of bulk MoS2 with soft organic exfoliation reagents. For edge functional exfoliation, the electrophilic 4-carboxy-benzenediazonium used as the soft organic reagent attacks the nucleophilic thiolates exposed at the edge of the bulk MoS2 with the help of an amine catalyst, resulting in 1T edge functional HOOC-benzene-2H basal MoS2 nanosheets (e-MoS2). The cross -linking via hydrogen bonding of the negatively charged HOOC of the e-MoS2 sheets with the help of a cationic polymer, polydiallyldimethylammonium chloride, results in a good film formation for a channel of the solution processing TFT. The TFT exhibits an extremely high mobility of 170 cm(2)/(V s) at 1 V (on/off ratio of 106) on SiO2/Si substrate and also a high mobility of 36.34 cm(2)/(V s) (on/off ratio of 10(3)) on PDMS/PET substrate. © 2017 American Chemical Society