Water-penetration-assisted mechanical transfer of large-scale molybdenum disulfide onto arbitrary substrates

Abstract

The transfer of two-dimensional (2D) material layers to arbitrary substrates from growth substrates is critical for many applications. Although several studies of transfer processes have been reported, a transfer method that does not degrade 2D layers and damage growth substrates is still required. In this paper, we report a method that with the assistance of water penetration enables the mechanical transfer of MoS₂, one of the most widely studied 2D materials, from the growth substrate to a target substrate without any etching of the growth substrate or leaving any polymer residue on the MoS₂ layer. The difference between the adhesion forces of the MoS₂ and carrier films and the difference between the hydrophobicities of MoS₂ and the growth substrate means that water can easily penetrate the interspace at the MoS₂/growth substrate interface generated by the peeling off process. We also experimentally confirmed the usefulness of Cu carrier films as a contact material for MoS₂ that enables its clean separation. Our transfer method protects the original quality and morphology of large area MoS₂ without leaving any polymer residue, and enables the reuse of the growth substrate. This clean transfer approach is expected to facilitate the realization of industrial applications of MoS₂ and other 2D materials.