1207.1237 (Tomasz Smoleński et al.)

Radiative lifetime of dark excitons in self-assembled quantum dots    [PDF]

Tomasz Smoleński, Tomasz Kazimierczuk, Mateusz Goryca, Tomasz Jakubczyk, Łukasz Kłopotowski, Łukasz Cywiński, Piotr Wojnar, Andrzej Golnik, Piotr Kossacki

We demonstrate an evidence for radiative recombination channel of dark excitons in self-assembled quantum dots. The time-resolved magnetospectroscopy of single CdTe/ZnTe quantum dots was used to extract the zero magnetic field dark exciton lifetime, which varied for different dots from 30ns to over 2\mu{}s. We found the strong dependence of this lifetime on the degree of light hole admixture to the excitonic ground state. This admixture creates a radiative recombination channel for the dark exciton. Photons created from its recombination are emitted only in the direction perpendicular to the growth axis. This was confirmed by a direct observation of the dark exciton photoluminescence from a cleaved edge of the sample.

View original: http://arxiv.org/abs/1207.1237