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.
@article{arxiv.1207.1237,
title = {In-plane radiative recombination channel of a dark exciton in self-assembled quantum dots},
author = {Tomasz Smoleński and Tomasz Kazimierczuk and Mateusz Goryca and Tomasz Jakubczyk and Łukasz Kłopotowski and Łukasz Cywiński and Piotr Wojnar and Andrzej Golnik and Piotr Kossacki},
journal= {arXiv preprint arXiv:1207.1237},
year = {2013}
}