Strained monolayer germanene with 1 × 1 lattice on Sb(111)

Monolayer germanene, the germanium analog of graphene, has been successfully synthesized on Sb(111) surface via molecular beam epitaxy. Scanning tunneling microscopy revealed a dendrite structure at low Ge coverage and mosaic patterns at high coverage, both with local 1 × 1 lattice. First-principle calculations confirmed the 1 × 1 low-buckled structure of germanene. The dendrite and mosaic patterns stem from strain modulation induced by large lattice mismatch between germanene and Sb substrate. This work provide a new system to explore the physical properties and applications of germanene.