In-plane radiative recombination channel of a dark exciton in   self-assembled quantum dots
  We demonstrate evidence for a radiative recombination channel of dark excitons in self-assembled quantum dots. This channel is due to a light hole admixture in the excitonic ground state. Its presence was experimentally confirmed by a direct observation of the dark exciton photoluminescence from a cleaved edge of the sample. The polarization resolved measurements revealed that a photon created from the dark exciton recombination is emitted only in the direction perpendicular to the growth axis. Strong correlation between the dark exciton lifetime and the in-plane hole g-factor enabled us to show that the radiative recombination is a dominant decay channel of the dark excitons in CdTe/ZnTe quantum dots. 
Tomasz Smole\'nski, Tomasz Kazimierczuk, Mateusz Goryca, Tomasz   Jakubczyk, {\L}ukasz K{\l}opotowski, {\L}ukasz Cywi\'nski,...
cond-mat.mes-hall