High-mobility patternable MoS2 percolating nanofilms

• Published in: Nano research Vol. 14; no. 7; pp. 2255 - 2263
• Main Authors: Gao, Xiangxiang, Yin, Jun, Bian, Gang, Liu, Hai-Yang, Wang, Chao-Peng, Pang, Xi-Xi, Zhu, Jian
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.07.2021
• Subjects: Assembly; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Chemistry and Materials Science; Condensed Matter Physics; Electrostatic properties; Fabrication; Field effect transistors; Flexible components; Integrated circuits; Materials Science; Molybdenum; Molybdenum disulfide; Nanotechnology; Percolation; Polyethylene; Polyethylene terephthalate; Research Article; Semiconducting films; Semiconductor devices; Substrates; Tactics; Thin films; Two dimensional materials; molybdenum disulfide; layer-by-layer assembly; field-effect transistors; nanofilms; solution-processed electronics
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-020-3218-6

Fabrication of large-area and uniform semiconducting thin films of two-dimensional (2D) materials is paramount for the full exploitation of their atomic thicknesses and smooth surfaces in integrated circuits. In addition to elaborate vapor-based synthesis techniques for the wafer-scale growth of 2D films, solution-based approaches for high-quality thin films from the liquid dispersions of 2D flakes, despite underdeveloped, are alternative cost-effective tactics. Here, we present layer-by-layer (LbL) assembly as an effective approach to obtaining scalable semiconducting films of molybdenum disulfide (MoS 2 ) for field-effect transistors (FETs). LbL assembly is achieved by coordinating electrochemically exfoliated MoS 2 with cationic poly (diallyldimethylammonium chloride) (PDDA) through electrostatic interactions. The PDDA/MoS 2 percolating nanofilms show controlled and self-limited growth on a variety of substrates, and are easily patterned through lift-off processes. Ion gel gated FETs are fabricated on these MoS 2 nanofilms, and they show mobilities of 9.8 cm 2 ·V −1 ·s − 1, on/off ratios of 2.1 × 10 5 with operating voltages less than 2 V. The annealing temperature in the fabrication process can be as low as 200 °C, thereby permitting the fabrication of flexible FETs on polyethylene terephthalate substrates. The LbL assembly technique holds great promise for the large-scale fabrication of flexible electronics based on solution-processed 2D semiconductors.