Reflection high-energy electron diffraction and optical measurements on the molecular-beam epitaxial growth of one and two monolayers of InAs on GaAs

Abstract

We report here on the reflection high-energy electron diffraction, photoluminescence (PL), and photoluminescence excitation study of the direct growth by molecular-beam epitaxy of one and two monolayers (MLs) of InAs on GaAs. InAs can be grown pseudomorphically up to a thickness of 1 ML, deposition of 2 MLs results in three-dimensional nucleation. In the latter case our results suggest that the first ML is disrupted by the growth of the second. This finding is in contradiction of the Stranski–Krastanov growth mode. A 1-ML InAs quantum well (QW) with GaAs barriers produces intense luminescence at 1.465 eV, whereas for the intended 2-ML InAs QW sample, PL characteristic of InAs clusters with a most probable thickness of 3 MLs is observed.