Abstract
We analyze time-resolved spontaneous emission from excitons confined in self-assembled InAs quantum
dots placed at various distances to a semiconductor-air interface. The modification of the local density of
optical states due to the proximity of the interface enables unambiguous determination of the radiative and
nonradiative decay rates of the excitons. From measurements at various emission energies, we obtain the
frequency dependence of the radiative decay rate, which is only revealed due to the separation of the radiative
and nonradiative parts. It contains detailed information about the dependence of the exciton wave function on
quantum dot size. We derive the quantum optics theory of a solid-state emitter in an inhomogeneous environment
and compare this theory to our experimental results. Using this model, we extract the frequency dependence
of the overlap between the electron and hole wave functions. We furthermore discuss three models of
quantum dot strain and compare the measured wave-function overlap to these models. The observed frequency
dependence of the wave-function overlap can be understood qualitatively in terms of the different compressibility
of electrons and holes originating from their different effective masses and binding energies.
Original language | English |
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Journal | Physical Review B Condensed Matter |
Volume | 80 |
Issue number | 15 |
Pages (from-to) | 155307 |
ISSN | 0163-1829 |
DOIs | |
Publication status | Published - 2009 |
Bibliographical note
Copyright 2009 American Physical SocietyKeywords
- PHOTONIC CRYSTALS
- MICROCAVITY
- OPTICAL-PROPERTIES
- SPONTANEOUS EMISSION
- DYNAMICS