Large Size MoS2 Nanosheets by Electrochemical Exfoliation Using Mixture of THA+ and 4-NBD+ Cations

Abstract

Electrochemical exfoliation of MoS2 using quaternary ammonium cations is widely applied for obtaining 2-dimensional (2D) materials for transistors, having advantages in creating minimal phase transition. However, this method generates nanosheets with small lateral size and decreased charge transporting efficacy. Here, large MoS2 nanosheets with an average lateral size of 2.67 μm (range 0.58~ 10 μm) were acquired by electrochemical exfoliation using a 4:1 wt% mixture of THA+ and 4-NBD+ cations. The produced MoS2 nanosheets showed covalent attachment of 4-NP on the surface on the surface of MoS2 creating a repulsion force generating large sized nanoflakes. The transistors fabricated with exfoliated MoS2 nanosheets by THA+ and 4-NBD+ mixture showed good performance, comparable to the single flake MoS2 transistors. This novel top-down liquid-phase exfoliation method using a THA+ and 4-NBD+ mixture could lead to fabrication of transistors with improved performance and cost-effectiveness.