Growth and characterization of cooperative quantum dot chains in quaternary InAsSbP material system

Abstract

The cooperative quantum dot chains (CQDCs) are grown from In-As-Sb-P quaternary liquid phase on InAs(100) substrate with a deviation of surface orientation from (100) of about 0.3° along [010] direction. The wet chemical etching is utilized to create an additional artificial disorientation of the substrate. AFM investigations show that CQDCs mainly consist of central coupled InAsSb quantum dot (QD) sub-chains surrounded by InAsP-leaf chains. Cooperative chains have a ∼120 nm total width, over 5 μm length and directed along [010]. The separation between QDs within sub-chains is about 40 nm. The red shift of CQDCs’ absorption edge is detected.