Tuning electrical and interfacial thermal properties of bilayer MoS₂via electrochemical intercalation

Layered two-dimensional (2D) materials such as MoS₂have attracted much attention for nano- and opto-electronics. Recently, intercalation (e.g. of ions, atoms, or molecules) has emerged as an effective technique to modulate material properties of such layered 2D films reversibly. We probe both the electrical and thermal properties of Li-intercalated bilayer MoS₂nanosheets by combining electrical measurements and Raman spectroscopy. We demonstrate reversible modulation of carrier density over more than two orders of magnitude (from 0.8 × 10¹²to 1.5 × 10¹⁴cm^-2), and we simultaneously obtain the thermal boundary conductance between the bilayer and its supporting SiO₂substrate 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 MW m^-2K^-1before intercalation to 1.8 ± 0.9 MW m^-2K^-1when the MoS₂is fully lithiated. These results reveal electrochemical intercalation as a reversible tool to modulate and control both electrical and thermal properties of 2D layers.