Lateral carrier diffusion in InGaAs/GaAs coupled quantum dot-quantum well system
| Autor: | Grzegorz Sęk, Maciej Pieczarka, D. Biegańska, Marcin Syperek, Jan Misiewicz, Johann Peter Reithmaier, C. Gilfert, E. M. Pavelescu |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Photoluminescence Physics and Astronomy (miscellaneous) Condensed matter physics Band gap Phonon 02 engineering and technology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Condensed Matter::Materials Science 0103 physical sciences Density of states Diffusion (business) 010306 general physics 0210 nano-technology Ground state Spectroscopy Excitation |
| Zdroj: | Applied Physics Letters. 110:221104 |
| ISSN: | 1077-3118 0003-6951 |
| DOI: | 10.1063/1.4984747 |
| Popis: | The lateral carrier diffusion process is investigated in coupled InGaAs/GaAs quantum dot-quantum well (QD-QW) structures by means of spatially resolved photoluminescence spectroscopy at low temperature. Under non-resonant photo-excitation above the GaAs bandgap, the lateral carrier transport reflected in the distorted electron-hole pair emission profiles is found to be mainly governed by high energy carriers created within the 3D density of states of GaAs. In contrast, for the case of resonant excitation tuned to the QW-like ground state of the QD-QW system, the emission profiles remain unaffected by the excess kinetic energy of carriers and local phonon heating within the pump spot. The lateral diffusion lengths are determined and present certain dependency on the coupling strength between QW and QDs. While for a strongly coupled structure the diffusion length is found to be around 0.8 μm and monotonically increases up to 1.4 μm with the excitation power density, in weakly coupled structures, it is deter... |
| Databáze: | OpenAIRE |
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