Coherent Bragg imaging of strained semi-conductor nanostructures

Imaging nanostructures with coherent phonon pulses

We demonstrate submicron resolution imaging using picosecond acoustic phonon pulses. High-frequency acoustic pulses are generated by impulsive thermoelastic excitation of a patterned 15-nm-thick metal film on a crystalline substrate using ultrafast optical pulses. The spatiotemporal diffracted acoustic strain field is measured on the opposite side of the substrate, and this field is used in a t...

Dynamic diffraction artefacts in Bragg coherent diffractive imaging

This article reports a theoretical study on the reconstruction artefacts in Bragg coherent diffractive imaging caused by dynamical diffraction effects. It is shown that, unlike the absorption and refraction effects that can be corrected after reconstruction, dynamical diffraction effects have profound impacts on both the amplitude and the phase of the reconstructed complex object, causing stron...

Automotive semi-conductor trend & challenges

The automotive electronics has been introduced with multiple waves over the time: powertrain, safety & vehicle dynamic, body & convenience, telematics. The future is already knocking at the door and revolutionary systems are currently developed: X-by-wire, E-safety, Hybrid vehicle. The increasing requirements for fuel economy, safety, emission reduction, and onboard diagnosis push the automotiv...

Stable unidimensional arrays of coherent strained islands

We investigate the equilibrium properties of arrays of coherent strained islands in heteroepitaxial thin films of bidimensional materials. The model we use takes into account only three essential ingredients : surface energies, elastic energies of the film and of the substrate and interaction energies between islands via the substrate. Using numerical simulations for a simple Lennard-Jones soli...

Smart, Biocompatible Semi-conductor Nanocrystal Constructs