Electrically driven single photon source based on a site-controlled quantum dot with self-aligned current injection

Electrical operation of single photon emitting devices employing site-controlled quantum dot (QD) growth is demonstrated. An oxide aperture acting as a buried stressor structure is forcing site-controlled QD growth, leading to both QD self-alignment with respect to the current path in vertical injection pin-diodes and narrow, jitter-free emission lines. Emissions from a neutral exciton, a neutral bi-exciton, and a charged exciton are unambiguously identified. Polarization-dependent measurements yield an exciton fine-structure splitting of (84 +/- 2) mu eV at photon energies of 1.28-1.29 eV. Single-photon emission is proven by Hanbury Brown and Twiss experiments yielding an anti-bunching value of g((2))(0)=0.05 under direct current injection. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767525]