Localization of defects in InAs QD symmetric InGaAs/GaAs DWELL structures

✍ Scribed by J.L. Casas Espínola; T.V. Torchynska; E. Velasquez Lozada; L.V. Shcherbyna; A. Stintz; R. Peña Sierra

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 207 KB
• Volume: 401-402
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2007.09.027

✦ Synopsis

The photoluminescence (PL), its power and temperature dependences have been studded for the ensembles of InAs quantum dots (QD) embedded in symmetric In 0.15 Ga 0.85 As/GaAs quantum wells prepared at different QD growth temperatures from the range 470-535 1C. The solution of the set of rate equations for exciton dynamics was used to analyze the nature of thermal activation energies of the QD PL quenching. It is revealed three different stages of thermally activated quenching of the QD PL intensity caused by thermal escape of excitons from the In 0.15 Ga 0.85 As/GaAs buffer and capping quantum wells (QWs) into the GaAs barrier and from the QDs into the GaAs barrier or into barrier/QW interfaces with their subsequent nonradiative recombination. The variety of activation energies of PL thermal quenching is discussed as well.