Exciton dynamics of a single quantum dot embedded in a nanowire

Gregory Sallen (1) , Adrien Tribu (2) , Thomas Aichele , Régis André (1) , Lucien Besombes (1) , Catherine Bougerol (1) , Serge Tatarenko (1) , Kuntheak Kheng (2) , Jean-Philippe Poizat (1)

1 NEEL - NPSC - Nanophysique et Semiconducteurs
2 SP2M - UMR 9002 - Service de Physique des Matériaux et Microstructures

We have carried out a detailed optical characterization of a single CdSe quantum dot embedded in a ZnSe nanowire. Exciton, biexciton, and charged exciton lines have been identified unambiguously using photon correlation spectroscopy. This technique has provided a detailed picture of the dynamics of this system. It has been found that the dark exciton has a strong influence on the optical properties. The most visible influence is the strongly reduced excitonic emission compared to the biexcitonic one. Temperature-dependent lifetime measurements have allowed us to measure a large splitting of ΔE=(6.0±0.2) meV between the dark and the bright exciton as well as the spin-flip rates between these two states. This type of semiconducting quantum dot turns out to be a very efficient single photon source in the visible. Its particular growth technique opens additional possibilities as compared to the usual self-assembled quantum dots.

Mots clés: quantum dot; spectroscopy; nanowire

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Gregory Sallen, Adrien Tribu, Thomas Aichele, Régis André, Lucien Besombes, et al.. Exciton dynamics of a single quantum dot embedded in a nanowire. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2009, 80, pp.085310. ⟨10.1103/PhysRevB.80.085310⟩. ⟨hal-00999541⟩