Investigation of the growth of PTCDA on Cu(1 1 0): an STM study

The growth of the organic semiconductor 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on Cu(1 1 0) was studied by STM. The PTCDA coverage was varied from submonolayer to multilayer. For submonolayer and monolayer coverage the PTCDA molecules induce a restructuring of the underlying Cu(1 1 0) surface by addition or removal of Cu-rows in the [1 1̄ 0]-direction. The rectangular PTCDA superstructure indicates a strong interaction between the substrate and PTCDA. Investigation of higher coverage of PTCDA shows that it grows in the Stranski–Krastanov-mode. Well ordered mesatype three-dimensional-crystallites are formed. Both the top layer and the flanks were molecularly resolved allowing to analyze the layer by layer growth and the crystal structure.