Template Driven Self-Assembly of the Pentacene Structure on the Si(553)-Pb Surface

Abstract

The self-assembly of the pentacene molecules on the Pb-ordered Si(553) surface is studied with scanning tunneling microscopy and density functional theory methods. Within the surface coverage up to a single monolayer, pentacene was found to form two different chain-like structures. They vary in molecular density, but both exhibit long-range, one-dimensional ordering with longer molecular axes aligned along step edges. The low-density phase consists of single discontinuous molecular rows and adapts the template surface periodicity, while the high-density phase features triple molecular chains with the unit cell determined by the length of the pentacene molecules. Such an arrangement of the molecules is controlled by a subtle balance between molecule–molecule and molecule–substrate interactions.