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

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  ~ 330 K and the doping state is fixed by quenching the device to ~ 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.