Formation trends in quantum dot growth using metalorganic chemical vapor deposition

We discuss the results of a growth matrix designed to produce high quantum dot (QD) density, defect-free QD ensembles, which emit at 1.3 μm using metalorganic chemical vapor deposition (MOCVD). In our study, we balance the nucleation rate and adatom surface migration to achieve high surface densities (1×1011 dots/cm2) and avoid QD coalescence or defects that commonly characterize MOCVD-grown QD ensembles designed for longer wavelength emission. Room-temperature photoluminescence (PL) spectra from corresponding surface QDs depend on QD size and density and show an emission wavelength up to 1600 nm. Ground-state PL from capped QDs is measured at 1.38 μm with a 40 meV linewidth. We demonstrate the ground-state 1.3 μm electroluminescence from a QD light-emitting diode structure grown on n-type GaAs.