Carrier relaxation in Si/SiO2_2 quantum dots

Carrier relaxation due to both optical and nonradiative intraband transitions in silicon quantum dots in SiO$_2$ has been considered. Interaction of confined holes with optical phonons has been studied. The Huang-Rhys factor is calculated for such transitions. The probability of intraband transition of a confined hole emitting several optical phonons is estimated.Comment: 8 pages, 2 figures, submitted as an extended abstract to the E-MRS Spring Meeting 200

Quantum wells with zero valence-band offset: Drastic enhancement of forbidden excitonic transitions.

International audienceForbidden e1hh3 and e1lh3 exciton transitions (where hh and lh are heavy-hole and light-hole, respectively) appear in magnetooptical spectra of quantum wells that undergo a type-I-type-II band-alignment transition, here for ordinary (In,Ga)As/GaAs multiple quantum wells and a single CdTe quantum well with a (Cd,Mn)Te semimagnetic barrier exhibiting a giant Zeeman effect. The oscillator strength becomes so strong in a field of 11.25 T that vacuum-field Rabi splitting is clearly seen in reflection spectra when the e1lh3 exciton transition couples to the two-dimensional optical mode in a microcavity