Institut d’Electronique Fondamentale
Personnel
Laboratory Contact Details
Website: http://www.ief.u-psud.fr/
Key Member: Philippe Dollfus
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Description
The simulation group at IEF has a long term experience in developing device simulation codes. In particular, it has developed for many years the simulator MONACO which is based on the particle Monte Carlo (MC) to solve the semiclassical Boltzmann transport equation self-consistently with 1D, 2D or 3D Poisson's equation. This simulator has been used to study many transport problems in advanced semiconductor devices but also for spin polarized transport in III-V heterostructures, and extended to carbon nanotube transistors, in particular within ANR/PNANO projects HF-CNT and ACCENT. Among numerous developments recently introduced in the code, one can mentioned the full-band description by coupling with k.p calculation, the multisubband transport in FET by self-consistent coupling with the Schrödinger equation and the Monte Carlo solution of the Wigner quantum transport equation for RTDs, MOSFETs and CNTFETs. These extensions have been partially supported by the ANR/PNANO project MODERN coordinated by IEF. They have placed the code MONACO at the present state of the art of advanced Monte Carlo device simulations.
For the Monte Carlo simulation of CNTFET, in the frame of the project ACCENT, IEF already benefits from the experience of CEA in advanced TB simulation to improve the simulation of Schottky contacts. The same CEA groups are also partners of NANOSIM_GRAPHENE.
In parallel to this work on particle MC simulation, IEF has recently developed capabilities in quantum transport simulation within the non-equilibrium Green's function (NEGF) formalism for devices such as RTD, double-gate MOSFET and graphene structures. In the latter case an original treatment of the Dirac equation has been proposed for the specific case of massless electrons. Tight-binding have been also implemented, in particular to study the edge disorder effects in GNRs.
In the project NANOSIM_GRAPHENE, IEF will develop and use the NEGF formalism for simulating the transport in devices within either a TB Hamiltonian in the case of small-width nanoribbons or the Dirac equation for larger structures. The TB Hamiltonian should be less sophisticated than that developed by CEA on the basis of ab initio calculation but suitable for larger devices under high bias for a reasonable computational cost and will include phonon scattering. Refined parameters obtained by CEA will be introduced when possible. The interaction with CEA is thus an opportunity to develop a multiscale approach bridging fundamental calculation and full device simulation as realistic as possible.
The TB-NEGF approach of phonon transport also developed in the project by IEF is a new activity for this group which develops in parallel a semi-classical treatment (Boltzmann equation) of phonon transport in more conventional semiconductor devices.
Group Publications
- Graphene nanomesh-based devices exhibiting a strong of negative differential conductance effect
- Resonant tunneling structures based on epitaxial graphene on SiC
- Giant effect of negative differential conductance in graphene nanoribbon p-n heterojunctions
- Enhanced thermoelectric properties in graphene nanoribbons by resonant tunneling of electrons
- Large peak-to-valley ratio of negative differential conductance in graphene p-n junctions
- Spin-polarized current and tunneling magneto-resistance in ferromagnetic gate bilayer graphene structures
- Edge shape effect on vibrational modes in graphene nanoribbons: a numerical study
- Modelling of metal-graphene coupling and its influence on transport properties in graphene at the charge neutrality point
- Negative differential resistance in zigzag-edge graphene nanoribbon junctions
- Conduction gap in double gate bilayer graphene structure
- Resonant tunneling and negative transconductance in single barrier bilayer graphene structure
