Strongly confined excitons in self-assembled InGaAs quantum dot clusters produced by a hybrid growth method.

We investigate the optical properties of newly developed InGaAs quantum dot clusters (QDCs). The QDCs are produced using a hybrid growth method that combines droplet homoepitaxy and Stranski–Krastanov growth modes. We focus on a particular geometry, where six individual quantum dots (QDs) spontaneously form a structure morphologically similar to a benzene ring. We observe narrow exciton resonances in microphotoluminescence measurements. Temperature and excitation density dependence of the exciton resonances are investigated. Our experiments suggest that excitons are strongly confined in individual QDs instead of residing in all QDs in the cluster. [ABSTRACT FROM AUTHOR]