Search

The adsorption of zwitterionic molecules on Si(111)-7×7 substrates has been probed by scanning tunneling microscopy and spectroscopy and studied via density-functional-theory calculations. Experimental results obtained at room and low temperatures revealed the reconstruction of Si(111)-7×7 half-cells with molecular constructs accommodating three zwitterions. A structural model for the inscription of the Si(111)-7×7 half-cell with zwitterionic edifices is proposed and the nature of the interactions between the molecular assemblies and the surface is established thanks to joint experimental data and simulations.

Organic nanostructures on semiconductors are currently investigated but the surfaces are known to interact strongly with molecules. To reduce the molecule-surface interaction, we used the Si(111)-B √3 × √3R30°. Deposition of isolated 2,4,6-tri(2t-thienyl)-1,3,5-triazine, was achieved at room temperature without modification of their π skeleton. This fascinating arrangement, observed by STM, has been validated by full density functional theory computations onto the entire system. The theoretical results give a clear explanation for the specific adsorption sites of molecules on the substrate.