Institut des Sciences Moléculaires d'Orsay




Sunday 21 October

Site update
Friday 19 October

Home > Research Teams > Surfaces, Interfaces: Réactivité et Nanostructuration (SIREN)

Surfaces, Interfaces: Réactivité et Nanostructuration (SIREN)

The SIREN team investigates the physical and chemical properties of surfaces mainly covered by molecular systems and/or clusters for which we try to measure the structural parameters and understand the mutual interactions. For instance, the absorption of reactive species (H2, H2O, etc.) can lead to a spontaneous nanostructuration. For self-assembled molecular layers, the interactions depend on the density and number of layers. Either we observe directly the organization by STM or GIFAD or we apply molecular spectroscopy (HREELS, SFG) to identify specific molecular terminations, their orientation, and environment. Well controlled low energy electrons are also used to induce energy specific reactions and to graft specific terminations.
These technics described below are now connected together via an ultra-high vacuum tunnel to better combine topology and spectroscopy. The application span astrophysics, radiobiology, thin layer growth, molecular electronics chemical and biological sensors

Fast Atom Diffraction

After discovering that fast (keV) atoms can diffract on crystal surfaces, we have developped the technique. It can image large dimensions of the crystal surface with a resolution reaching 10 pm. The inelastic component highlights surface defects (steps, ad-atoms) and dynamical aspects of the surface (vibrational excitations, electron-hole pair creations..).

Read more

Interfaces, Nanostructures and Interactions Dynamics

Objectives: create metal-molecule ordered héterostructures as well as chalcogenide materials, families of low dimensional materials with novel properties of interest in applications such as molecular electronics. We do this using synchrotron radiation, complemented by scanning tunnelling microscopy and ion scattering.

Read more

Surface chemistry & slow electrons, 0-50eV

Low-energy electron beams of controlled energy make it possible both, to analyse the chemical compositions of surfaces and interfaces, and to induce specific chemical reactions. The aims of the work carried out concern the identification of the species and interaction mechanisms involved, and the quantitative evaluation of the efficiency of the chemical processes induced under radiation.

Read more

Nano-architecture moléculaires et surfaces nanostructurées.

By combining local probe (STM) and electronic spectroscopies (XPS/UPS) the group interest is focused on the study and control of formation of organic molecular layers on surfaces at meso/macro scale and aim at using its experience in chemical reactivity induced nano-structuration of metal surfaces to use them as original substrate morphologies.

Read more

Molecular Femtophysics at interfaces

Combining a broadband femtosecond (fs) IR laser with a narrowband visible laser, we generate a sum frequency signal (SFG) which allows vibrational spectroscopy. We use it to study the interaction of molecules with mono- and bimetallic nanoparticles (NP). Ordered array of NPs having a narrow size distribution allows to study shape and size effects from 4 to 500 atoms by means of STM and SFG. Pump probe experiments allow to study desorption and diffusion accross NP sites. Self assembled molecules and biological materials are also studied with SFG.

Read more

Thin Layer

thin layer growth.

Read more