Tuning electrical and interfacial thermal properties of bilayer MoS2 via electrochemical intercalation.

Layered two-dimensional (2D) materials such as MoS2 have attracted much attention for nano- and opto-electronics. Recently, intercalation (e.g. of ions, atoms, or molecules) has emerged as an effective technique to reversibly modulate material properties of such layered 2D films. Here we probe both electrical and thermal properties of Li-intercalated bilayer MoS2 nanosheets by combined electrical measurements and Raman spectroscopy. We demonstrate reversible modulation of carrier density over more than two orders of magnitude (from 0.8×1012 cm 2 to 1.5×1014 cm-2), and we simultaneously obtain the thermal boundary conduct-ance (TBC) between the bilayer and its supporting SiO2 substrate for an intercalated system for the first time. This thermal coupling can be reversibly modulated by nearly a factor of eight, from 14 ± 4.0 MWm-2K-1 before intercalation to 1.8 ± 0.9 MWm 2K-1 when the MoS2 is fully lithiated. These results reveal electrochemical intercalation as a reversible tool to modulate and control both electrical and thermal properties of 2D layers.