The epitaxial growth and unique morphology of InAs quantum dots embedded in a Ge matrix

Abstract In this work, we investigate the epitaxial growth of InAs quantum dots (QDs) on Ge substrates. By varying parameters temperature, deposition thickness and rate InAs, high density (1.2 × 10 11 cm −2 ) self-assembled QDs were successfully epitaxially grown substrates by solid-source molecular beam epitaxy capped layers. Pyramid- polyhedral-shaped embedded in matrices revealed, which are distinct from lens- or truncated pyramid-shaped InAs/GaAs InAs/Si systems. Moreover, with a 200 nm capping layer, one-third found elliptical hexagonal nanovoids sizes 7–9 nm, which, to best our knowledge, is observed for first time matrix. These results provide new possibility integrating QD devices group-IV platforms Si photonics.