Dark exciton decay dynamics of a semiconductor quantum dot

✍ Scribed by Dalgarno, Paul A. ;Smith, Jason M. ;Gerardot, Brian D. ;Govorov, Alexander O. ;Karrai, Khaled ;Petroff, Pierre M. ;Warburton, Richard J.

• Book ID: 105363543
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 590 KB
• Volume: 202
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200562029

✦ Synopsis

Abstract

We report measurements of the exciton decay dynamics of a single self‐assembled quantum dot following non‐resonant excitation. The singly charged exciton, the trion, exhibits a simple one component exponential decay corresponding to radiative recombination. Conversely, the neutral exciton exhibits a two component exponential decay. We argue that the secondary component arises from dark exciton creation and subsequent conversion to a bright exciton through a spin flip. The spin flip time is a strong function of the bias applied between a Fermi reservoir close to the dot and a Schottky gate electrode as a result of a Kondo‐like spin swap process. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)