Morphology evolution of InSb island grown on InP substrates by atomic layer molecular beam epitaxy

Abstract

The growth evolution of capped InSb quantum dots grown on InP(001) substrates is reported for a range between 0.6 and 15 monolayers of InSb deposited by atomic layer molecular beam epitaxy. TEM studies have been performed in order to follow the progression in dot size and morphology. After the transition from an initial two-dimensional to a three-dimensional growth mode at 1.1 ML there is a range in which InSb nanometre scale islands are homogeneously distributed. Raman spectra have also been recorded to assess the effects of the introduction of the capping layer covering the islands, comparing the results with those of uncapped samples. The activation of the InSb TO mode is discussed in terms of the facetting of the dots by (001) and {111} sides observed prior to the cap deposition.