Comparison of Ionic Liquid and Ion-Gel Top-Gate MoS2 Field-Effect Transistors

Abstract

Polymer electrolytes and ionic liquids (ILs) have attracted significant interest in applications as gate dielectrics. In this study, we fabricated top-gated molybdenum disulfide (MoS2) thin-film transistors using IL and ion-gel (IG) gate dielectrics. Room-temperature Raman spectra measurements indicated a dominant peak spectral emission at 358 cm−1 (E1 2g) and 406.44 cm−1 (A1g) associated with bilayer MoS2 films. The fabricated thin-film field-effect transistors (FET) with IG gate dielectric exhibited band transport with a highest mobility of 0.5 cm2/V⋅s, and a poor ION/IOFF ratio of ~10. By contrast, the FET with IL gate dielectric exhibited a 3400 % improvement in terms of the mobility (17.9 cm2/V⋅s), and a 1000 % improvement of the ION/IOFF ratio (~100).