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

Abstract

In this paper, we investigate the effects of growth temperature and growth rate on the formation of InAs/GaAs quantum dots (QDs) grown by metalorganic chemical vapor deposition. These QDs are formed with large InAs coverage (3.0 MLs) and periodic growth interruption via the Stranski–Krastanow epitaxial growth mode. The photoluminescence (PL) spectra at 300 K exhibit a red shift in peak wavelength by decreasing the InAs growth temperature from 540°C to 500°C. As the growth rate increases from 0.05 to 0.2 ML/s at a growth temperature of 500°C, the PL linewidth decreases and the PL intensity increases. These results are related to the In clusters and uniformity of InAs/GaAs QDs, which are observed by scanning electron microscopy (SEM). Finally, the room-temperature PL spectrum of InAs/GaAs QDs directly capped with GaAs layer shows an emission wavelength at 1.35 μm and a narrow linewidth of 30.8 meV.