Growth and characterization of single quantum dots emitting at 1300 nm

Abstract

We have optimized the molecular-beam epitaxy growth conditions of self-organized InAs∕GaAs quantum dots (QDs) to achieve a low density of dots emitting at 1300 nm at low temperature. We used an ultralow InAs growth rate, lower than 0.002ML∕s, to reduce the density to 2dots∕μm2 and an InGaAs capping layer to achieve longer emission wavelength. Microphotoluminescence spectroscopy at low-temperature reveals emission lines characteristic of exciton-biexciton behavior. We also study the temperature dependence of the photoluminescence, showing clear single QD emission up to 90 K. With these results, InAs∕GaAs QDs appear as a very promising system for future applications of single photon sources in fiber-based quantum cryptography.