title: Tuning of polarization sensitivity in closely stacked trilayer InAs/GaAs quantum dots induced by overgrowth dynamics.
abstract: Tailoring of electronic and optical properties of self-assembled InAs quantum dots (QDs) is a critical limit for the design of several QD-based optoelectronic devices operating in the telecom frequency range. We describe how fine control of the strain-induced surface kinetics during the growth of vertically stacked multiple layers of QDs allows for the engineering of their self-organization process. Most noticeably, this study shows that the underlying strain field induced along a QD stack can be modulated and controlled by time-dependent intermixing and segregation effects occurring after capping with a GaAs spacer. This leads to a drastic increase of the TM/TE polarization ratio of emitted light, not accessible from conventional growth parameters. Our detailed experimental measurements, supported by comprehensive multi-million atom simulations of strain, electronic and optical properties, provide in-depth analysis of the grown QD samples allowing us to give a clear picture of the atomic scale phenomena affecting the proposed growth dynamics and consequent QD polarization response.
authors.affiliation: National Nanotechnology Laboratory, Istituto Nanoscienze CNR, Via Arnesano, I-73100 Lecce, Italy.
authors.forename: Vittorianna
authors.initials: V
authors.lastname: Tasco
authors.forename: Muhammad
authors.initials: M
authors.lastname: Usman
authors.forename: Milena
authors.initials: M
authors.lastname: De Giorgi
authors.forename: Adriana
authors.initials: A
authors.lastname: Passaseo