Efficiency of spin injection in novel InAs quantum dotstructures: exciton vs. free carrier injection
2010 (English)Conference paper (Refereed)
Unambiguous experimental evidence for a significant difference in efficiency of excitonic vs. free carrier spin injection is provided in novel laterally arranged self-assembled InAs/GaAs quantum dot structures, from optical orientation and tunable laser spectroscopy. A lower efficiency of exciton spin injection as compared to free carrier spin injection from wetting layers into QDs results in a distinct feature in luminescence polarization of the QDs as a function of excitation photon energy. It is shown that this difference is not related to carrier density and state-filling effects arising from the difference in optical absorption efficiency between the excitons and free carriers. Rather, it is a genuine property for exciton spin injection that suffers stronger spin relaxation due to Coulomb exchange interaction.
Place, publisher, year, edition, pages
IOP , 2010. 012044- p.
, Journal of Physics: Conference Series, ISSN 1742-6596 ; 245
National CategoryCondensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-60486DOI: 10.1088/1742-6596/245/1/012044OAI: oai:DiVA.org:liu-60486DiVA: diva2:356911
Quantum Dots 2010, 26–30 April 2010, Nottingham, UK