Liquid-Phase Exfoliation of Germanane Based on Hansen Solubility Parameters

Two-dimensional (2D) materials combine the collective advantages of individual building blocks and synergistic properties and have spurred great interest as a new paradigm in materials science. For the mass production of these materials, large-scale exfoliations are the main production route; but, recent approaches in the liquid-phase exfoliation are based on empirical trial and error strategies. This study aims to propose a method to determine the suitable solvents for efficiently exfoliating germanane (GeH) and the optimal solvent removal conditions at moderate temperatures using Hansen solubility parameters. We confirm the presence of GeH nanosheets using atomic force microscopy. The proposed method revealed that GeH can be efficiently dispersed in 1,3-dioxolane and can be deposited as individual sheets, which have the thickness of 3–4 nm and the lateral size in the range of a few micrometers.