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Time‐Resolved Capacitance Spectroscopy of Hole and Electron Levels in InAs/GaAs Quantum Dots
Author(s) -
Kapteyn C.M.A.,
Lion M.,
Heitz R.,
Bimberg D.,
Brunkov P.,
Volovik B.,
Konnikov S.G.,
Kovsh A.R.,
Ustinov V.M.
Publication year - 2001
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200103)224:1<57::aid-pssb57>3.0.co;2-r
Subject(s) - quantum dot , quantum tunnelling , electron , excited state , spectroscopy , capacitance , ground state , condensed matter physics , atomic physics , materials science , scanning tunneling spectroscopy , molecular physics , physics , optoelectronics , electrode , quantum mechanics
Carrier escape from self‐organized InAs quantum dots (QDs) embedded in GaAs is studied by time‐resolved capacitance spectroscopy. Thermal activation energies of 82 meV and 164 meV are determined for electrons and holes, respectively. We observe electron tunneling from the QD ground state and, at elevated temperatures, thermally activated tunneling from excited states. For holes, thermal activation from the QD ground state to the GaAs valence band is identified. We find good agreement with predictions of the level structure by eight‐band k · p theory. The capture cross sections of ≈5 × 10 —12 cm 2 for holes and ≈3 × 10 —12 cm 2 for electrons correspond to the lateral size of the QDs.