Formation of crystalline Si 9 C 15 nano-islands and Si 9 C 15 /graphene heterostructures on Ru(0001)

Abstract Two-dimensional silicon carbides have attracted increasing interest due to their highly tunable band structures and rich physical properties. Among them, Si 9 C 15 is particularly notable for its intrinsic auxeticity, strongly anisotropic carrier mobility, and pronounced optical and thermoelectric responses. However, the controlled growth of Si 9 C 15 nano-islands has remained a challenge. Here, we report a novel growth technique for Si 9 C 15 nano-islands. By exploiting the mild segregation of carbon atoms from a Ru(0001) substrate, we fabricate discrete, crystalline Si 9 C 15 nano-islands at temperatures as low as ∼400 °C. Spectroscopic measurements reveal a spatial modulation of the local work function across the nano-island, which we attribute to the periodic potential landscape of the Si 9 C 15 lattice. Furthermore, we demonstrate that this island morphology enables the construction of Si 9 C 15 /graphene lateral heterostructures. Our work establishes a new pathway for fabricating Si 9 C 15 nanostructures as well as the heterostructures.