Stepped silicon surfaces as templates for one-dimensional nanostructures

It is shown how atomically precise step arrays can be fabricated on vicinal Si(111). Decoration with metal atoms produces atomic chains that serve as the ultimate nanowires for the study of electrons between one and two dimensions. Chain structures are formed by a large variety of metal atoms with different chemical properties. They range from alkali and alkaline earth metals to noble metals and include transition metals (Pt) and rare earths (Gd, Ho). As a first step toward functionalizing such surfaces, we demonstrate how NEXAFS spectroscopy characterizes organic layers in atom- and orbital-specific fashion, with examples ranging from alkanes with customized end groups to DNA oligonucleotides.