Templated growth of 3,4,9,10-perylenetetracarboxylic dianhydride molecules on a nanostructured insulator

Nanometre-scale 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) crystallites were produced by trapping the molecules inside monolayer-deep rectangular pits on an alkali halide surface. Noncontact atomic force microscopy was used to measure the crystallite dimensions and lattice structure with molecular resolution. The molecule-substrate lattice mismatch and island heights, typically three to four PTCDA layers, indicate a stress in the first two layers. One- and two-layer crystallites were only observed in pits with side lengths smaller than 10 nm.