Toward printing molecular nanostructures from microstructured samples in ultrahigh vacuum

Transferring molecular nanostructures from one surface to another in ultrahigh vacuum (UHV) by mechanical contact might be a possible route to avoid the severe limitations of in situ molecular synthesis on technologically relevant template surfaces. Here, transfer printing in UHV of molecular structures between metal surfaces is investigated by a combination of scanning tunneling microscopy and scanning electron microscopy/energy dispersive x-ray spectroscopy. The authors present the complete procedure of the printing and characterization process. Microstructured Au-coated MoS₂ samples exhibiting a periodic pillar structure are used as stamp surfaces with Au(111) single crystals as target surface. Polymers of 1,3,5-tris(4-bromophenyl)benzene molecules and graphene nanoribbons with an armchair edge structure are grown on the pillars of the stamp surface. After bringing the two surfaces in mechanical contact, the transferred material is found on the target while decapping occurs on the stamp surface. Polymer structures are probably buried under the transferred stamp material, and in rare cases, evidence for molecular structures is found in their vicinity.