Picosecond time-resolved study of excitons in GaAs-A1As multi-quantum-well structures

Time-resolved study of intervalence band thermalization in a GaAs quantum well

The thermalization of optically excited cold holes in a GaAs quantum well is investigated by femtosecond two-color pump–probe measurements. Clear evidence is found for scattering from heavy-holes into the lowest light-hole band due to LO-phonon absorption. We obtain firm data on scattering times which depend strongly on lattice temperature. They vary from 230 fs at room temperature to 900 fs at...

Quantum well intermixing in GaInNAs/GaAs structures

A novel model on time-resolved photoluminescence measurements of polar InGaN/GaN multi-quantum-well structures

Based on carrier rate equation, a new model is proposed to explain the non-exponential nature of time-resolved photoluminescence (TRPL) decay curves in the polar InGaN/GaN multi-quantum-well structures. From the study of TRPL curves at different temperatures, it is found that both radiative and non-radiative recombination coefficients vary from low temperature to room temperature. The variation...

Time-resolved photoluminescence of type-II Ga(As)Sb/GaAs quantum dots embedded in an InGaAs quantum well.

Optical properties and carrier dynamics in type-II Ga(As)Sb/GaAs quantum dots (QDs) embedded in an InGaAs quantum well (QW) are reported. A large blueshift of the photoluminescence (PL) peak is observed with increased excitation densities. This blueshift is due to the Coulomb interaction between physically separated electrons and holes characteristic of the type-II band alignment, along with a ...

Imaging Spectroscopy of Two-Dimensional Excitons in a Narrow GaAs AlGaAs Quantum Well

We report the observation of a sharp absorption line in the photoluminescence excitation spectra of individual naturally occurring quantum dots in a narrow (2.8 nm) GaAs Al0.3Ga0.7As quantum well that is remarkably constant throughout the sample. We propose that it is identified as the delocalized two-dimensional exciton. This assignment is confirmed by photoluminescence and photoluminescence e...