Suppression of competing tunneling processes in thermally-activated carrier emission on self-assembled InAs quantum dots

Link:

Autor/in:

Erscheinungsjahr:

2008

Medientyp:

Text

Beschreibung:

Electron emission from charged self-assembled InAs quantum dots is studied by means of deep level transient spectroscopy in strong magnetic fields applied parallel to the quantum-dot layer. Since a magnetic field oriented parallel to the quantum-dot layer strongly suppresses electron tunneling our experiments give valuable information about the contribution of tunneling processes to the emission. We probe both the low-temperature signal, which is found to be dominated by pure tunneling from the quantum-dot p states as well as the magnetic-field dependence of the thermally-activated emission. The thermally-activated emission from the s states is found to be only slightly affected by a parallel magnetic field. In contrast, for the thermally-activated emission from the p states, we find significant changes that we discuss in the frame of a thermally-activated tunneling model for the emission from multielectron states of the quantum dots. A conventional analysis of the decreasing tunneling rates in a parallel magnetic field yields an increase of apparent activation energies and capture cross sections of quantum dot p electrons. The results confirm that the tunneling path in thermally-activated processes becomes increasingly important with increasing occupation number of the dots. © 2008 The American Physical Society.

Lizenz:

Quellsystem:

Forschungsinformationssystem der UHH

Interne Metadaten

Quelldatensatz: oai:www.edit.fis.uni-hamburg.de:publications/77e7e306-a605-4719-a184-3ccc4619cba9