Van der Waals epitaxy of topological insulator Bi2Se3 on single layer transition metal dichalcogenide MoS2

We report the growth of high quality topological insulator Bi2Se3 thin films on a single layer, transitional metal dichalcogenide MoS2 film via van der Waals epitaxy in a planar geometry. In stark contrast to the reported growth of using 3-D crystalline substrates such as Al2O3(0001), Bi2Se3 thin films grown on a 2-D template made of single layer MoS2 showed excellent crystallinity starting immediately from the growth of the first quintuple layer. Excellent crystallinity of Bi2Se3 thin films is attained, with the increased size of the triangular shaped Bi2Se3 domains and 2–3 times enhancement in mobility, along with the observation of Shubnikov–de Haas oscillations in the magnetoresistance. Our approach of adopting a van der Waals type template may be extended to the thin film growth of other low dimensional layered materials.