Design of 2D V 6 S n Se 6− n Cl 6 ( n =0, 2, 3, 5) with multilayer Kagome lattice and ultrahigh electron mobility

Abstract Two-dimensional (2D) Kagome materials have attracted considerable attention due to their unique electronic properties. Based on first-principles calculations and employing the ‘1 + 3’ design strategy, we designed a class of composition-tunable 2D multilayer Kagome materials, V 6 S n Se 6− n Cl 6 , and identified four stable structures: V 6 Se 6 Cl 6 , V 6 S 2 Se 4 Cl 6 , V 6 S 3 Se 3 Cl 6 , and V 6 S 5 Se 1 Cl 6 . 2D V 6 S n Se 6− n Cl 6 possesses three Kagome layers, two of which are vanadium-based Kagome layers, and the other is a sulfur or selenium atomic layer. Electronic structure analysis reveals that 2D V 6 S n Se 6− n Cl 6 is a narrow direct-bandgap semiconductor with a bandgap ranging from 0.568 to 0.742 eV, and exhibits ultrahigh electron mobility up to 4 × 10 4 cm 2 V −1 s −1 . Orbital analysis further demonstrates that the bands contributed by the V-based Kagome layers form flat bands and Dirac cones below the Fermi level, and show a relatively high band velocity. In summary, 2D V 6 S n Se 6− n Cl 6 provides an excellent platform for Kagome physics research and the fabrication of nanoelectronic devices, adaptable to various device scenarios.