One-shot current conserving inelastic transport modeling
Fig.1: Illustration of the current degradation in double-gate MOSFETs resulting from electron-phonon interactions. In this case the one-shot LOA+AC method perfectly reproduces the SCBA results [2]. We describe a lowest-order approximation (LOA) to the nonequilibrium Green’s function in the presence of interactions, and generally address how one can build Phi-derivable one-shot approximations that satisfy the...
Read More
Enhanced thermopower in the transient regime
Fig.1: Increase of the Seebeck coefficient in the transient regime of a metal/dot/metal junction. Collaboration with A. Crépieux, CPT Marseille We derived formal expressions of time-dependent energy and heat currents through a nanoscopic device using the Keldysh nonequilibrium Green function technique. Numerical results are reported for a metal/dot/metal junction where the dot level energy is...
Read More
Quantum PV effect in hetero-nanowire junctions
Following that idea of combining one-dimensional and zero-dimensional nanostructures, like in photonics devices, we investigated the photovoltaic response of a mesoscopic junction in which the light is absorbed in a quantum dot laterally connected to two quantum wires on each side Fig. 1. The transport and optical properties have then been determined using a powerful...
Read More
Quantum modeling of thin film solar cells
Fig. 1: Current spectrum calculated in a thin film (180 nm) GaAs solar cell. The corresponding PCE is 8.8%. In addition to the expected positive current we show a negative contribution at the device edges (labeled as LEC for Large Energy Contribution). Carriers generated at energy larger than the junction barrier are less sensitive to...
Read More
Dynamical spin Hall conductivity in a magnetic disordered system
FIG. 1 : Schematic geometry of the spin Hall effect; a longitudinal current jx driven by an external electric field induces a transversal spin current that results in a polarization of the carrier spins following the sign of their momentum (spheres with arrows). We investigate the intrinsic spin Hall effect in a quantum well semiconductor...
Read More
Modeling of p-type MOS transistors
Fig. 1: Illustration of the multi-band effect on the local density of states and transmission coefficient in a Si p-type double-gate MOSFET whose transport direction is along [100]. VDS = -0.4V and VG = 0V. For sake of clarity the bandstructures and potentials are represented in terms of hole energy [1,2]. Complementary metal oxide semi-conductor...
Read More
