Narrow spectral linewidth from single site-controlled In(Ga)As quantum dots with high uniformity

We present narrow spectral linewidth from single site-controlled In(Ga)As quantum dots (QDs) grown on nanoholes, which were defined by electron beam lithography on a (100) GaAs substrate. The long-range ordering of uncapped QDs is confirmed by electron microscopy whereas the ordering of capped QDs is visualized by atomic force microscopy. We find a small inhomogeneous broadening of 14.4 meV for the ensemble emission of site-controlled QDs with 300 nm lattice period. The photoluminescence from the excitonic transitions of single site-controlled QDs exhibits linewidth values down to 43 μeV, which is promising for the investigation of pronounced cavity quantum electrodynamic effects in scalable QD-microresonator systems.