Possible charge-density-wave signatures in the anomalous resistivity of Li-intercalated multilayer MoS2

Highlights: • Li ions are intercalated in MoS₂ flakes by electrochemical gating above 320 K. • Superconductivity is suppressed in Al₂O₃-encapsulated Li_xMoS₂ multilayers. • Anomalous "humps" in the temperature dependence of the resistivity appear ∼200 K. • Proposed explanation by the emergence of a high-doping charge-density-wave phase. We fabricate ion-gated field-effect transistors (iFET) on mechanically exfoliated multilayer MoS₂. We encapsulate the flake by Al₂O₃, leaving the device channel exposed at the edges only. A stable Li⁺ intercalation in the MoS₂ lattice is induced by gating the samples with a Li-based polymeric electrolyte above $\sim 330$ K and the doping state is fixed by quenching the device to $\sim 300$ K. This intercalation process induces the emergence of anomalies in the temperature dependence of the sheet resistance and its first derivative, which are typically associated with structural/electronic/magnetic phase transitions. We suggest that these anomalies in the resistivity of MoS₂ can be naturally interpreted as the signature of a transition to a charge-density-wave phase induced by lithiation, in accordance with recent theoretical calculations.