Large-Area Self-Assembly of Rubrene on Au(111) Surface

Large-area self-assembly of rubrene has been fabricated on Au(111) surface and studied by scanning tunnelling microscopy. The rubrene monolayer on Au(111) surface is characterized by well-ordered row-like structures similar to the a -- b plane of rubrene single crystal. However, the directions of the neighboured molecular rows are opposite to each other. In a two-layer film of rubrene on Au(111) surface, the arrangements of the top molecular rows are determined by the underneath rows, suggesting an orthorhombic crystal structure with a = 1.26 nm, b = 4.36 nm, c = 0.17nm for multilayer of rubrene on Au(111).