Dresden 2014 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 65: Quantum Dots: Optical Properties II (organized by HL)
TT 65.6: Vortrag
Mittwoch, 2. April 2014, 12:45–13:00, POT 251
Excitons in InAs-quantum dots measured by capacitance-voltage spectroscopy — Patrick Labud, •Arne Ludwig, Andreas D. Wieck, and Dirk Reuter — Ruhr-Universität Bochum, Lehrstuhl für Angewandte Festkörperphysik
Electron-electron and hole-hole interaction has been studied intensively on self-assembled quantum dot (QD) samples using capacitance-voltage spectroscopy (C-V) since two decades. The energetic positions of the charging peaks are considerably affected by the Coulomb interaction energies and in standard C-V spectra only the Coulomb repulsion is seen.
In this contribution, we present C-V data obtained under nonresonant illumination from a light emitting diode. Under these conditions, additional charging peaks appear due to attractive Coulomb interaction between illumination induced holes and electrons, tunnelling into the QD.
We are able to resolve up to five additional charging peaks belonging to an X0, X1+, X2+, X3+, X4+-complex, formed upon electron charging. The individual Coulomb energies are calculated from the charging gate voltage and the charging dynamics is discussed.