Electronic and optical properties of semiconductor nanostructures (well, wire, and dots) are studied by applying both envelope function approximation and full band approaches such as tight-binding and pseudopotentials. Our research cover the following areas:

• Strained quantum well (GaN, InGaAsP, AlGaAs etc.)
• Si, GaN nanowires
• AlGaAs/GaAs quantum wires

High electron mobility transistors (HEMTs) and heterojunction bipolar ransistors (HBTs) based on GaAs, GaN, InP are the most widely used microwave devices for low noise and power applications. We performed both Monte Carlo and Drift-Diffusion approaches to investigate:

• Impact-ionization regime
• Reliability
• RF response

Active and passive optoelectronic devices are the backbone of optical communication systems. With a variety of simulation tools, ranging from sophisticated Monte Carlo analysis to beam propagation methods, we perform:

• Modeling of semiconductor optical amplifiers, optical switches and lasers
• Full band calculation of optical gain (tight-binding, pseudopotentials)
• Theoretical study of dynamical properties based on rate-equation approaches

A proper analysis of the optical and transport properties of semiconductor nanostructured devices requires sophisticated multiscale simulators. They should account, on equal footing, the atomistic details of the nanostructured active region as well as the macroscopic details of the whole device (contacts, strain, potential etc.). To this end OLAB is developing the multiscale Technology CAD called TiberCAD. Several features are considered in this tool:

• 3D drift-diffusion for electron, holes and excitons
• Strain, piexo and pyro polarization
• Tight-binding models (empirical and DFT) for the atomistic description