PHYSICS of NANOSTRUCTURES
This theme includes the most fundamental researches of IEMN, involving ‘Physics’, ‘Epiphy’ and ‘Nanostructures, nanoComponents & Molecules’ group activities. The activity consists in studies of thin layers, hetero- and periodic structures and nanostructures (2D, 1D, 0D) of advanced materials for electronics, optics, acoustics, opto-electronics and nanotechnology. They include theoretical and experimental research in several directions:
– Materials and nanostructures for molecular electronics
– Structure and dynamical properties of materials
– Growth and characterization of 1D and 2D semiconductor heterostructures and interfaces
– Transport, optoelectronic/photovoltaic properties and theoretical studies of 1D and 0D semiconductor nanostructures
– Graphene on SiC and metals
– Phononics/phoXonics, plasmonics, and nanoacoustics in micro and nanostuctured materials
These subjects are part of 2 main IEMN thematics, i.e. ‘Nano-characterization’ and ‘Flexible electronics’, and strongly participate in the emerging ones: ‘Graphene and beyond graphene’, ‘Electronics and sustainable development’, ‘Neuro-inspired architectures’.
Means and methods
For the theoretical works, the main used techniques are the multi-scale simulation, the molecular dynamics for the analysis of molecule-surface interactions, semi-empirical (tight binding) and ab-initio (DFT and beyond) techniques applied to the electronic structure of nanostructures and interfaces between semiconductors and oxides with high lattice mismatch, Boltzmann equations, and Green’s function methods for electron transport.
For experimental investigations, we have important technical facilities: 3 MBE machines devoted to III-V semiconductors and graphene epitaxy on SiC, 2 CVD ovens for graphene growth on metals and group-IV element nanowire growth, an ESCA machine, 8 near-field microscopes (4 ambient air and 4 UHV systems), one µ-photoluminescence set-up, one cryostat for low temperature electrical measurements under magnetic field, one picosecond acoustic set-up, one platform for “organic materials and devices” (3 glovebox with vaccuum and solution deposition and electrical facilities inside) and a chemistry lab for organic synthesis.
Summary of the objectives
- Physics of nanostructures and nanodevices made of organic molecules and/or hybrid systems involving organic molecules, inorganic metal and/or semiconductor nanostructures. Fundamental electronic and transport properties of various molecular devices.
- Design, fabrication and study of functional molecular devices such as memory, switch, memristor and synapstor (synapse-transistor) for neuro-inspired computing architectures and “biocompatible synapse prosthesis”.
Structure and dynamical properties of materials
- Thermodynamics and physical chemistry of nanostructured systems, macromolecular aggregates and biomolecules at finite temperature and pressure, and under constraints (mechanical, chemical) by computer simulations.
- Range of the physical-chemical phenomena of interest from supramolecular ordering to interfacial adhesion and aggregation, microscopic mechanics and radiation damage in biomolecules.
Growth and characterization of 1D and 2D semiconductor heterostructures
- MBE growth and physical characterization of III-V based heterostructures for opto, microelectronic applications as well as for mesoscopic physics. Highly mismatched heterostructures in the aim of using the ‘6.1 Å family’ material system (InAs, GaSb,…) properties for advanced devices.
- Theoretical approach of strained relaxation in highly mismatched systems.
- Epitaxial growth of III-V (MBE) and of Si/Ge (CVD) nanowires and nanostructures on various substrates.
Transport, optoelectronic properties and theoretical studies of 1D and 0D semiconductor nanostructures
- Experimental and theoretical spectroscopy studies of zero-dimensional (0D) semiconductor nanostructures with the aim to probe their electrical, electronic, optical and photovoltaic properties at the level of individual nanoparticles, including scanning probe (STM, AFM/EFM/KFM) and transport properties of Si or III-V 1D nanowires.
- Theoretical investigation of the structural, electronic and heat transport of 1D nanostructures (semiconductor nanowires, carbon or boron nitride nanotubes) of interest for ultimate electronic devices.
Graphene epitaxy on SiC and metals
- Development of an original MBE growth approach of graphene on SiC with the aim of a precise mastering of the graphene layer thickness.
- CVD using a CH4/H2 gas mixture for graphene growth on metals (mainly Cu and Ni) before report on insulating substrates.
Phononics/phoXonics, plasmonics, and nanoacoustics in micro and nanostuctured materials
- Theoretical study of acoustic wave propagation in phononic crystal slabs and on the phonon-photon interaction in phoXonic cavities and waveguides.
- Theoretical propagation and filtering of surface plasmon polaritons in metal-insulator-metal waveguides; localized surface plasmon resonance of arrays of gold nanostructures for biosensing applications.
- Experimental mechanical characterization on thin films and vibrations of nanoscale objects using picosecond acoustics.