Bottom up synthesis of topological crystalline insulator SnTe nanostructures with controlled facets and morphologies

Tin Telluride (SnTe) has recently been demonstrated to be a topological crystalline insulator with unique metallic surface states protected by crystalline mirror symmetry. The topological surface properties have been predicted to depend on the surface orientation. By combining synthesis experiments and density functional theory (DFT) calculations, we demonstrate the growth of single crystalline nanostructures of SnTe with controlled facets and morphologies. In particular, by tailoring the growth temperature, we obtained two types of single crystalline nanowires: smooth nanowires dominated by \textbraceleft 100\textbraceright facets at high temperatures, and zigzag nanowires composed of both \textbraceleft 100\textbraceright and \textbraceleft 111\textbraceright surfaces at low temperatures. No \textbraceleft 110\textbraceright facet was observed in any of our nanostructures. The experiment results agree well with our DFT calculations of surface energies. Our device fabrication and preliminary electrical characterizations suggest that both types of nanowires are suitable for transport studies.