Germanium, a Unique Template for 2D Materials Growth: From Germanene to Antimony Telluride Synthesis

Germanene is an artificial two-dimensional graphene-like germanium allotrope predicted to be a near room temperature topological insulator, belonging to the class of so-called Xenes. It was synthesized in 2014, exactly ten years after the isolation of graphene, and just two years after the archetype growth of silicene, the first Xene ever produced. The canonical germanene paper, described its top-down synthesis by Ge deposition onto a Au(111) crystal, but revealed multi-phases [1]. Instead, we will show that a single germanene phase, as evidenced in Scanning Tunneling Microscopy in situ imaging, is obtained by Ge segregation on top of a thin Au(111) film epitaxially grown under ultra-high vacuum on a Ge(111) template through a bottom-up approach. [2] A comparison with studies performed on thin gold film epitaxially grown on a Ge(110) template will be presented.<br/>Eventually, we will describe the growth of antimony telluride films on Ge(111) surface using a single evaporator cell. Moreover, we will discuss the structural and electronic characterization of such films, studied using standard surface science techniques (LEED, STM, PES).<br/><br/>[1] M.E. Dávila <i>et al.</i>, New Journal of Physics, 16, 095002 (2014)<br/>[2] M. Minissale <i>et al.</i>, Crystals 13, 221 (2023)