Single-photon light-emitting diodes based on preselected quantum dots using a deterministic lithography technique

Abstract

In the present study, we developed a deterministic fabrication process for an electrically driven single-photon light-emitting diode based on InP quantum dots (QDs) emitting in the red spectral range, where the wavelength of interest coincides with the high efficiency window of most commonly available standard Si avalanche photodiodes (APDs). A deterministic lithography technique allowed for the preselection of a suitable QD, here exclusively operated under electrical carrier injection. The final device was characterized under micro-electroluminescence in the direct current as well as in pulsed excitation mode. In particular, under pulsed excitation of one device, single-photon emission has been observed with graw(2)(0)=0.42 ± 0.02, where the nonzero g(2)-value is mainly caused by background contribution in the spectrum and re-excitation processes due to the electrical pulse length. The obtained results constitute an important step forward in the fabrication of electrically driven single-photon sources, where deterministic lithography techniques can be used to sensibly improve the device performances. In principle, the developed process can be extended to any desired emitter wavelength above 600 nm up to the telecom bands.