Dynamical photo-induced electronic properties of molecular junctions

Nanoscale molecular-electronic devices and machines are emerging as promising functional elements, naturally flexible and efficient, for next generation technologies. A deeper understanding of carrier dynamics in molecular junctions is expected to benefit many fields of nanoelectronics and power-devices. We determine time-resolved charge current flowing at donor- acceptor interface in molecular junctions connected to metallic electrodes by means of quantum transport simulations. The current is induced by the interaction of the donor with a Gaussian-shape femtosecond laser pulse. Effects of the molecular internal coupling, metal- molecule tunneling and light-donor coupling on photocurrent are discussed. We then examine the junction working through the time-resolved donor density of states. Non-equilibrium reorganization of hybridized molecular orbitals through the light-donor interaction gives rise to two phenomena: the dynamical Rabi shift and the appearance of Floquet-like states. Such insights into the dynamical photoelectronic structure of molecules are of strong interest for ultrafast spectroscopy, and open avenues toward the possibility of analyzing and controlling the internal properties of quantum nanodevices with pump-push photocurrent spectroscopy

Electroluminescence of metamorphic In x Al 1-x As / In x Ga 1-x As HEMTs ON GaAs substrate

We present the first impact ionization investigation by electroluminescence of InxAl1-xAs /InxGa1-xAs metamorphic High Electron Mobility transistors on GaAs. Two Indium content are investigated. First we observe the decrease of the detrimental effect of impact ionization with the decrease of the Indium content. Second, the electroluminescence measurements illuminate the functional relationship between impact ionization and the kink effect. In these metamorphic HEMT’s, we suggest that both kink effect and impact ionization threshold are originated to detrapping process of deep levels in the large band gap layer

Effective-mass approach for n-type semiconductor Nanowire MOSFETs arbitrarily oriented

International audienc

Nano-transistor MOS à ergot

National audienc

Tight-Binding Calculations of Ge-nanowire Bandstructures

International audienc

Modélisation du transport balistique dans des transistors MOS à nanofils arbitrairement orientés

National audienc

Tight-Binding Calculations of Ge-nanowire Bandstructures

International audienc

Tight-Binding Calculations of Ge-nanowires

International audienc