Electrochemical Doping of Two-Dimensional Superatomic Materials.

We report an electrochemical method for doping two-dimensional (2D) superatomic semiconductor Re₆Se₈Cl₂ that significantly improves the material's electrical transport while retaining the in-plane and stacking structures. The electrochemical reduction induces the complete dissociation of chloride anions from the surface of each superatomic nanosheet. After the material is dehalogenated, we observe the electrical conductivity (σ) increases by two orders of magnitude while the 3D electron carrier density (n_3D) increases by three orders of magnitude. In addition, the thermal activation energy (E_a) and electron mobility (μ_e) decrease. We conclude that we have achieved effective electron-doping in 2D superatomic Re₆Se₈Cl₂, which significantly improves the electrical transport properties. Our work sets the foundation for electrochemically doping and tuning the transport properties of other 2D superatomic materials.