Molecular-scale structure fabrication at liquid/solid interfaces

Nano-fabrication of organic molecules at liquid/solid interfaces is a promising method to form nano-structures of thermally unstable molecules on surfaces. Perylene-3,4,9,10-tetracarboxylic-dianhydride mono-molecular layer was formed on HOPG (0001) surface by vacuum-deposition as a canvas layer for nano-fabrication. After a droplet of 1-octylbenzene solution of 3- imino-4,5,6,7-tetrachloroisoindolin-1-one (ITCII) was placed on the surface, an STM tip was inserted into the droplet and a part of the canvas layer was scratched by the STM tip by increasing tunneling current. The scratched area was found to be immediately covered by ITCII molecules. In such way, ITCII mono-molecular layer with a designed shape could be fabricated. Structures of the formed layer are discussed in comparison to that of freely adsorbed layer.