Envelope Function Theory for Direct-gap Semiconductor Superlattices of Arbitrary Grading Profile

Dipole-allowed direct band gap silicon superlattices

Silicon is the most popular material used in electronic devices. However, its poor optical properties owing to its indirect band gap nature limit its usage in optoelectronic devices. Here we present the discovery of super-stable pure-silicon superlattice structures that can serve as promising materials for solar cell applications and can lead to the realization of pure Si-based optoelectronic d...

Semiconductor superlattices: a tool for terahertz acoustics.

The properties of optical to acoustic transduction of semiconductor superlattices have been explored for several years in the sub terahertz frequency range. Using femtosecond laser pulses focused on these structures, acoustic modes are excited with a frequency related to the periodicity of the structure stacking. We have shown that these acoustic waves can be extracted and can propagate in the ...

Electron Transport in Semiconductor Superlattices

In this paper, we rigorously derive a diffusion model for semiconductor superlattices, starting from a kinetic description of electron transport at the microscopic scale. Electron transport in the superlattice is modelled by a collisionless Boltzmann equation subject to a periodic array of localized scatters modeling the periodic heterogeneities of the material. The limit of a large number of p...

Spin instabilities in semiconductor superlattices

The subband levels of quantum wells grown in a periodic array form minibands whose bandwidth D depends on the probability of interlayer tunneling. In the presence of a strong magnetic field, this system of minibands can exhibit various Coulomb-interaction-driven spin polarization instabilities at an integral value of the filling factor n . We investigate in particular the Hartree-Fock phase dia...

Semiconductor superlattices with periodic disorder