Synthetic Nanosheets of Natural van der Waals Heterostructures

Abstract

Creation of new van der Waals heterostructures by stacking different two dimensional (2D) crystals on top of each other in a chosen sequence is the next challenge after the discovery of graphene, mono/few layer of h-BN, and transition-metal dichalcogenides. However, chemical syntheses of van der Waals heterostructures are rarer than the physical preparation techniques. Herein, we demonstrate the kinetic stabilization of 2D ultrathin heterostructure (ca. 1.13–2.35 nm thick) nanosheets of layered intergrowth SnBi2Te4, SnBi4Te7, and SnBi6Te10, which belong to the SnmBi2nTe3n+m homologous series, by a simple solution based synthesis. Few-layer nanosheets exhibit ultralow lattice thermal conductivity (κlat) of 0.3–0.5 W m−1 K−1 and semiconducting electron-transport properties with high carrier mobility.