Details
| Original language | English |
|---|---|
| Pages (from-to) | 11346-11353 |
| Number of pages | 8 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 54 |
| Issue number | 16 |
| Publication status | Published - 15 Oct 1996 |
| Externally published | Yes |
Abstract
We studied the electronic structure and relaxation processes in InAs quantum dots embedded in GaAs. Using capacitance measurements along with photoluminescence spectroscopy, we estimate the energy splitting between the ground and first excited quantum-dot state in the conduction and valence band, respectively. There are five quantum-dot transitions observable in our photoluminescence (PL) spectra, which we attribute to allowed transitions between electron and hole states of the same quantum number. Phonon-related relaxation processes were studied combining PL, resonant PL (RPL), and photoluminescence excitation (PLE) experiments. In the RPL as well as in the PLE spectra, we observed enhanced signals at twice the phonon energies available in the system. Therefore, a maximum in the intensity of the PLE and RPL signal does not necessarily occur when most of the dots are pumped resonantly into an excited state. The main criterion, however, seems to be that the energy distance between the pumped levels and the levels below matches a multiple of the available phonon energies. Changing the pump power in our resonant PL experiments corroborates that at least in the small carrier density regime phonon-related processes are important for the carrier relaxation in InAs quantum dots embedded in GaAs bulk material.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Physical Review B - Condensed Matter and Materials Physics, Vol. 54, No. 16, 15.10.1996, p. 11346-11353.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Carrier relaxation and electronic structure in InAs self-assembled quantum dots
AU - Schmidt, Klaus H.
AU - Medeiros-Ribeiro, G.
AU - Oestreich, Michael
AU - Petroff, P.
AU - Döhler, G.
PY - 1996/10/15
Y1 - 1996/10/15
N2 - We studied the electronic structure and relaxation processes in InAs quantum dots embedded in GaAs. Using capacitance measurements along with photoluminescence spectroscopy, we estimate the energy splitting between the ground and first excited quantum-dot state in the conduction and valence band, respectively. There are five quantum-dot transitions observable in our photoluminescence (PL) spectra, which we attribute to allowed transitions between electron and hole states of the same quantum number. Phonon-related relaxation processes were studied combining PL, resonant PL (RPL), and photoluminescence excitation (PLE) experiments. In the RPL as well as in the PLE spectra, we observed enhanced signals at twice the phonon energies available in the system. Therefore, a maximum in the intensity of the PLE and RPL signal does not necessarily occur when most of the dots are pumped resonantly into an excited state. The main criterion, however, seems to be that the energy distance between the pumped levels and the levels below matches a multiple of the available phonon energies. Changing the pump power in our resonant PL experiments corroborates that at least in the small carrier density regime phonon-related processes are important for the carrier relaxation in InAs quantum dots embedded in GaAs bulk material.
AB - We studied the electronic structure and relaxation processes in InAs quantum dots embedded in GaAs. Using capacitance measurements along with photoluminescence spectroscopy, we estimate the energy splitting between the ground and first excited quantum-dot state in the conduction and valence band, respectively. There are five quantum-dot transitions observable in our photoluminescence (PL) spectra, which we attribute to allowed transitions between electron and hole states of the same quantum number. Phonon-related relaxation processes were studied combining PL, resonant PL (RPL), and photoluminescence excitation (PLE) experiments. In the RPL as well as in the PLE spectra, we observed enhanced signals at twice the phonon energies available in the system. Therefore, a maximum in the intensity of the PLE and RPL signal does not necessarily occur when most of the dots are pumped resonantly into an excited state. The main criterion, however, seems to be that the energy distance between the pumped levels and the levels below matches a multiple of the available phonon energies. Changing the pump power in our resonant PL experiments corroborates that at least in the small carrier density regime phonon-related processes are important for the carrier relaxation in InAs quantum dots embedded in GaAs bulk material.
UR - http://www.scopus.com/inward/record.url?scp=0001215962&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.54.11346
DO - 10.1103/PhysRevB.54.11346
M3 - Article
AN - SCOPUS:0001215962
VL - 54
SP - 11346
EP - 11353
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 1098-0121
IS - 16
ER -