1.3 μm InAs/GaAs quantum dots directly capped with GaAs grown by metal organic chemical vapor deposition

Systematic studies of the growth temperature and growth rate effect of the formation of InAs/GaAs quantum dots (QDs) have been demonstrated. These QDs are formed with large InAs coverage (3.0 MLs) and periodic growth interruption via Strnski-Krastonov (S-K) epitaxial growth mode by using metalorganic chemical vapor deposition (MOCVD). The room temperature photoluminescence (PL) spectra show red-shift of peak wavelength by decreasing the InAs growth temperature from 540°C to 500°C. As growth rate increases from 0.05 ML/s to 0.2 ML/s at growth temperature of 500°C, PL linewidth could be narrowed and emission intensity could be increased. These results could be correlated to the In clusters and uniformity of InAs/GaAs QDs observed by scanning electron microscopy (SEM) image. Finally, the room temperature photoluminescence spectra of InAs/GaAs QDs directly capped with GaAs shows peak wavelength of 1.35 μm with narrow linewidth of 30.8 meV is obtained.