The institute
FEMTO's news

You are here

Room temperature stable molecules adsorbed on semi-conductors

The adsorption of functional molecules on surfaces plays a vital role in the emerging field of nanoelectronics. In this context, molecular and supramolecular ordering, which are key steps in the development of complexes architectures, are controlled by a balance between intermolecular forces and molecule–substrate interactions.

Isolated molecules on Si(111)-B

Isolated molecules on Si(111)-B

Isolated molecules on Si(111)-B
Image 8x12nm2

The deposition of organic molecules and preservation of their entire skeleton, especially on semiconductor surfaces, is still a challenge, although much progress has been made in the development of metallic surface-based devices with organic molecules at low temperature, where the molecule–surface interactions are weak and diffusion remains low. However, the use of metallic substrates is less attractive for potential applications as semiconductors, especially in the field of nanoelectronics.

2D-molecular star on Si(111) 7x7

2D-molecular star on Si(111) 7x7

2D-molecular star on Si(111) 7x7
Image 6x7nm2

In order to circumvent the problem of traditional silicon surface reactivity with pi-conjugated molecules, the Si(111)-B surface is used. This surface has the unique particularity to exhibit depopulated dangling bonds due to the presence of boron atoms under the top silicon layer. We have shown that the weak interactions between rich pi-electron molecules with empty pz depopulated dangling orbitals of the Si-B surface are most likely to be at the origin of the specific adsorption of isolated triazine molecules at the Si-B surface. This structure is stable at room temperature, and the pi-conjugated skeleton of organic molecules is preserved even after deposition [1].

We propose a new concept for the room-temperature deposition of pi-conjugated organic molecules, without any modification of their electronic structure, at specific adsorption sites on the surface of the semiconductor Si(111)-7x7 by adsorbing p-conjugated zwitterionic molecules on this semiconductor surface. The presence of a negative charge on the target molecules offsets the electrophilic character of the Si(111)-7x7 adatoms and preserves the p skeleton of the organic molecules after deposition. The half-cells of Si(111)-7x7 act as a template that guides the molecular assembly of achiral molecules, as shown by the induction of chirality in the modified areas [2].

The results reported herein are remarkable from several different points of view, especially the molecular assembly at room temperature, the chirality of the assembly, and the stability and conservation of the pi-conjugated skeleton on the semiconductor surface at room temperature. These strategies may become important methods for the deposition of pi-conjugated molecules.

Contact: frank.palmino@pu-pm.univ-fcomte.fr

The Nanosciences group are: Y. Makoudi (PhD), Dr F. Palmino, Dr E. Duverger, Dr F. Chérioux.

[1] Y. Makoudi, M. Arab, F. Palmino, E. Duverger, F. Chérioux, C. Ramseyer, M. J.-L. Tschan, B. Therrien, G. Süss-Fink, Phys. Rev. Lett., sous presse, parution Février 2008.

[2] Y. Makoudi, M. Arab, F. Palmino, E. Duverger, C. Ramseyer, F. Picaud, F. Chérioux, Angew. Chem. Int. Ed., 2007, 46, 9287-9290.

  • Using artificial intelligence to collect agricultural data

    ANR OCOD project combines intelligent sensors, drones and optimization for data collection in constrained natural environments

    Read more
  • A European project to prevent perineal tears

    PELVITRACK offers a predictive tool for patricians as part of an interdisciplinary European consortium involving FEMTO-ST.

    Read more
  • Best Paper Award at BIOSTEC 2025

    The work of Ouassim Boukhennoufa and his team combines AI and image optimization in nuclear medicine for more accurate and earlier detection of parathyroid anomalies.

    Read more
  • Kagomé structures for quantum technologies

    Quantum technologies open up promising prospects, but require the development of new materials with remarkable properties.

    Read more
  • Launch of the European SAMI project for energy-free intelligent sensors

    A major scientific and technological collaboration between Silmach and FEMTO-ST in the field of intelligent, autonomous sensors kicks off on January 30.

    Read more
  • RENATECH 2024 PhD AWARD

    Adria Grabulosa is rewarded for his work on 3D printed circuits using an original two-photon optical additive manufacturing technique.

    Read more
  • Elsevier article award at BFAS 2024

    Artificial intelligence applied to the electroerosion machining process : Loïc Guiziou1, Emmanuel Ramasso1, Sébastien Thibaud1 et Sébastien Denneulin2 won second prize for best paper at the 8th International Conference on Belief Functions.

    Read more
  • Tribute to our colleague Sarah Benchabane

    The CNRS and the university community of Bourgogne Franche-Comté are in mourning following the death of Sarah Benchabane, Director of Research at the CNRS and internationally renowned researcher in phononics, affiliated to the FEMTO-ST laboratory.

    Read more
  • Does the i-motif structure of DNA exist in the cell?

    As part of an interdisciplinary project involving FEMTO-ST, a new scientific study is reopening the debate on the very existence of these structures in DNA and their potential therapeutic interest in cell biology for the treatment of certain cancers.

    Read more
  • Pink October: A smart bra project

    Zeina Al Masry talks to France 3 TV about her innovative connected bra project for the early detection of breast cancer.

    Read more

Pages