Self-assembled quantum dots as active emitters for silicon photonic crystal nanocavities

We present a study of the properties of active (Si)Ge self-assembled quantum dot (QD) emitters coupled to Si photonic crystal (PC) nanocavities up to room temperature and evaluate the potential of such nanostructures for the realization of efficient silicon based light sources in the near-infrared regime. The Si-Ge system allows the formation of type I and type II band alignment QD, depending on the epitaxy conditions. We first discuss the emission properties of different types of QD. In particular we present type I SiGe islands designed to produce a strong emission due to a large wave function overlap of confined electrons and holes. We then investigate the coupling properties of (Si)Ge QD emitters to 2D Si PC cavities. We interpret the experimentally observed correlation between the photoluminescence intensity of the QDs and the quality factor of the PC cavity using simulations based on a dissipative master-equation approach [1]. As a further step towards efficient light sources, we currently study the coupling of electrically pumped (Si)Ge QDs to 2D PC in contacted diode structures. [1] N. Hauke, et al. Phys. Rev. B 84, 085320 (2011)