Precise determination of molecular adsorption geometries by room temperature non-contact atomic force microscopy

High resolution force measurements of molecules on surfaces, in non-contact atomic force microscopy, are often only performed at cryogenic temperatures, due to needing a highly stable system, and a passivated probe tip (typically via CO-functionalisation). Here we show a reliable protocol for acquiring three-dimensional force map data over both single organic molecules and assembled islands of molecules, at room temperature. Isolated cobalt phthalocyanine and islands of C 60 are characterised with submolecular resolution, on a passivated silicon substrate (B:Si(111)- ( 3 × 3 ) R 3 0 ∘ ). Geometries of cobalt phthalocyanine are determined to a ~ 10 pm accuracy. For the C 60 , the protocol is sufficiently robust that areas spanning 10 nm × 10 nm are mapped, despite the difficulties of room temperature operation. These results provide a proof-of-concept for gathering high-resolution three-dimensional force maps of networks of complex, non-planar molecules on surfaces, in conditions more analogous to real-world application. High resolution force measurements of molecules on surfaces using non-contact atomic force microscopy are typically performed at cryogenic temperatures. Here, the authors outline a reliable protocol for acquiring three-dimensional force map data at room temperature, demonstrating such capabilities on isolated cobalt phthalocyanine molecules and islands of C60 molecules.