Growth of InGaAs/GaAs nanowire-quantum dots on AlGaAs/GaAs distributed Bragg reflectors for laser applications

Abstract We report the formation of GaAs nanowires (NWs) containing In 0.2 Ga 0.8 As/GaAs quantum dots (QDs) on patterned Al 0.65 Ga 0.35 As/GaAs distributed Bragg reflectors (DBRs) grown on GaAs(111)B substrates. The growth conditions of both GaAs and Al 0.65 Ga 0.35 As layers on GaAs(111)B are optimized for the growth of high-quality Al 0.65 Ga 0.35 As/GaAs DBRs with (111) orientation in order to obtain high reflectivity at the NW/DBR interface. Moderately high growth temperature and low V/III ratio can mitigate the formation of pyramidal hillocks, resulting in the formation of high-quality DBRs on GaAs(111)B substrates. Optical characterization at 7 K of single GaAs NW cavities containing 75-stacked InGaAs/GaAs NWQDs grown on patterned such Al 0.65 Ga 0.35 As/GaAs DBRs/GaAs(111)B substrates exhibits lasing oscillation at 1.43 eV with a threshold pump pulse fluence of 250 μJ/cm 2 .