学术报告（12月21日）

主持人： 钟定永 教授

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摘要：Engineering sophisticated two-dimensional (2D) nanoarchitectures on surfaces is attracting considerable interest for applications in nanotechnology. The challenge consists of tailoring the ordering of atoms or molecules into specific architectures to build new materials.

We use scanning tunnelling microscopy (STM) in vacuum and also at the liquid-solid interface and in vacuum to investigate at the atomic scale the formation of self-assembled hydrogen and halogen-bonded organic nanoarchitectures. We observe in the case of star-shaped molecules, that the nature of peripherical substituent is a key parameter driving the self-assembly of the molecules. We show that we can tailor the structure of organic self-assembled nanoarchitectures and engineer compact as well as porous structures by changing the nature of the molecular substituents or mixing different building blocs. We also selectively engineered three two-dimensional self-assembled hybrid nanoarchitectures by mixing perylene derivatives with NaCl. STM reveals that NaCl-dimers selectively interact with molecular N–H groups and stabilize the formation of porous structures. Hybrid molecular-ionic self-assembly is a promising alternative to purely organic nanostructures to engineer novel nanoarchitectures on surfaces.

These examples show that the wise selection of molecular design as well as substituent nature and position allows us to prevent molecules to self-assemble into close-packed structures. Various porous two-dimensional organic nanoarchitectures can then be engineer on surfaces.

We in addition investigated the growth of nanocrystals after deposition of Cu and Pd atoms on differently-reconstructed SrTiO3(100) surfaces. We observed that Pd forms nanocrystals on the surface of SrTiO3(001), and depending on the crystallographic interface of the Pd with the substrate, three shapes can be created: truncated pyramids, huts, and hexagons. In comparison, we observed that Cu deposited on SrTiO3(001) leads to the formation of five-fold symmetry nanocrystals and fcc nanocrystals as a function of substrate temperature during Cu deposition.

报告人简介：Dr Silly completed his doctorate in physics with the investigation of photon emission induced by scanning tunneling microscopy on nanostructured surfaces at the Pierre and Marie Curie University, Paris, in 2001. After his experimental study of adatom self-organization mediated by two-dimensional electron gas on metal surfaces in Lausanne University, Switzerland, as a junior lecturer, he joined the Department of Materials at the University of Oxford, UK, in 2003, where he investigated the growth of supported nanocrystals using scanning tunneling microscopy (STM). He received the Young Scientist Award from the British Association of Crystal Growth and the Award of Merit from Department of Materials, University of Oxford for his work in 2005. He then joined in 2005 the Linköping University, Sweden, to characterize semiconducting surfaces using light-assisted STM. In 2006, Dr. Silly returned to the Department of Materials at the University of Oxford, UK, to investigate multicomponent supramolecular self-assemblies on surfaces. In 2007 he was appointed Assistant Professor at the University of Groningen, the Netherlands and in 2008 he joined the CEA Saclay, France, to develop his research activity in the area of nanoscience. In 2010, Dr Silly was awarded the prestigious Starting Grant by the European Research Council (ERC). He now runs a research group investigating the atomic scale structure and properties of supported hybrid magnetic nanoarchitectures.