Self-assembled InGaAs quantum dot superlattices

Well-ordered high-density quantum dot arrays of InGaAs have been fabricated on high-index substrates by atomic-hydrogen assisted molecular beam epitaxy. The density and the dot size are controlled by growth temperature and substrate structure. The dot growth mechanism is explained not only by simple strain relaxation but also by phase separation. The surface coverage of the high density quantum dots is almost 100 %, which implies the lateral coupling between the dots. Photoluminescence and photoconductivity measurements show the existence of minibands formed by lateral coupling of dots.