Room-temperature, ground-state lasing for red-emitting vertically aligned InAlAs/AlGaAs quantum dots grown on a GaAs(100) substrate

Abstract
The effect of the growth temperature on the properties of InAlAs/AlGaAs quantum dots grown on GaAs(100) substrates is investigated. The optical efficiency and structural uniformity are improved by increasing the growth temperature from 530 to 560 ° C . The improvements of InAlAs/AlGaAs quantum-dot characteristics could be explained by suppressing the incorporation of oxygen and the formation of group-III vacancies. Furthermore, edge-emitting laser diodes with six quantum-dot layers grown at 560 ° C have been fabricated. Lasing occurs via the ground state at 725 nm, with a room-temperature threshold current density of 3.9 kA / cm 2 , significantly better than previously reported values for this quantum-dot systems.