Growth of InAs/Sb:GaAs quantum dots by the antimony-surfactant mediated metal organic chemical vapor deposition for laser fabrication in the 1.3 μm band

摘要

We present a general method that improves the emission efficiency of InAs quantum dots (QDs) fabricated by antimony surfactant-mediated growth. Unlike conventional InAs/GaAs QDs, we show that the control of the interface properties of the InAs/Sb:GaAs QDs is crucial. Our method consists in growing InAs QDs on an antimony-irradiated GaAs surface, in order to exploit the surfactant properties of antimony, and then removing the excess segregated antimony by applying a high arsenic pressure before capping. In such a way, one benefits from the advantages of the antimony-surfactant mediated growth (high density QDs, no coalescence, no emission blueshift after annealing), without the detrimental formation of antimony-induced non-radiative defects. We show that the lasing characteristics of InAs/Sb:GaAs QD lasers grown by metal organic chemical vapor deposition in the 1.3 μm band are drastically improved, with a reduced threshold current density and higher internal quantum efficiency. These studies advance the understanding of key processes in antimony-mediated growth of InAs QDs and will allow full utilization of its advantages for integration in opto-electronic devices.