The effect of growth temperature of GaAs nucleation layer on InAs/GaAs quantum dots monolithically grown on Ge substrates

摘要

The effect of the growth temperature of the GaAs nucleation layer on the properties of 1.3-μm InAs/GaAs quantum dots (QDs) monolithically grown on a Ge substrate is investigated by using transmission electron microscopy, etch pit density, and photoluminescence (PL) measurements. The photoluminescence intensity for Ge-based InAs/GaAs quantum dots is very sensitive to the initial GaAs nucleation temperature with the strongest room-temperature emission at 380℃, due to the lower density of defects generated at the GaAs/Ge interface and prorogating into the Ⅲ-Ⅴ layers at this temperature. Furthermore, lasing operation up to 100℃ was achieved for Ge-based 1.3-μm InAs/GaAs quantum-dot diodes with the initial GaAs layer nucleated at 380℃.