Induced electrostatic confinement of electron gas in W strain-compensated Si/SiGe/Si type-II quantum wells

N. Sfina , J.L Lazzari (1) , Philippe Christol (1) , Y. Cuminal (1) , M. Saïd

1 CEM2 - Centre d'Electronique et de Micro-optoélectronique de Montpellier

We present a numerical modeling of the conduction- and the valence-band diagrams of W designed Si/Si0.4Ge0.6/Si type II quantum wells. These W structures, strain-compensated on relaxed Si0.75Ge0.25 pseudo-substrates, are potentially interesting for emission and photo-detection around a 1.55μm wavelength. Two main features have been extrapolated by solving self-consistently Schrödinger and Poisson equations, taking into account the electrostatic attraction induced by carrier injection: (i) Coulomb attraction strongly modifies the band profiles and increases the electron probability density at the quantum well interfaces. (ii) The injected carrier concentration enhances the in-plane oscillator strength and the electron-hole wave-function overlap.

Mots clés: Coulomb interaction; Charge carrier injection; Poisson equation; Schroedinger equation; Self consistency; Valence bands; Band structure; Confinement; Ge-Si alloys; Quantum wells; Silicon; Electron gas; Electrostatic interaction; Oscillator strengths; Carrier density; Wave functions; Electron density

Domaines: Electronique

N. Sfina, J.L Lazzari, Philippe Christol, Y. Cuminal, M. Saïd. Induced electrostatic confinement of electron gas in W strain-compensated Si/SiGe/Si type-II quantum wells. Journal of Luminescence, 2006, 121 (2), pp.421-425. ⟨10.1016/j.jlumin.2006.08.082⟩. ⟨hal-00328229⟩