Controllable growth of two-dimensional SnSe₂flakes with screw dislocations and fractal structures

Two-dimensional (2D) structured layered chalcogenide materials play a pivotal role in a wide range of applications owing to their exotic physical properties and flexible architectures. Here, we report on the controllable synthesis of 2D SnSe2 flakes with screw dislocations and fractal structures on mica and graphite substrates using a molecular beam epitaxy technique. Atomic force microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy were used to characterize the composition and crystal structures of the 2D SnSe2 flakes. We show that 2D SnSe2 flakes with tunable density of screw dislocations and fractal structures can be prepared by adjusting the growth parameters. This work offers new opportunities for engineering 2D materials with unique architectures to develop novel electronic devices and catalysts.