1. GaAs quantum dot molecules filled into droplet etched nanoholes
- Author
-
A. Küster, Ch. Heyn, Wiebke Hansen, A. Graf, A. Ungeheuer, and A. Gräfenstein
- Subjects
Coupling ,Fabrication ,Materials science ,business.industry ,Quantum dot molecules ,Physics::Optics ,02 engineering and technology ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Inorganic Chemistry ,Etching (microfabrication) ,Electric field ,0103 physical sciences ,Materials Chemistry ,Optoelectronics ,Optical emission spectroscopy ,010306 general physics ,0210 nano-technology ,business ,Luminescence ,Molecular beam epitaxy - Abstract
We fabricate self-aligned vertically stacked GaAs quantum dot molecules (QDMs) by filling of self-assembled nanoholes in AlGaAs. The tunable nanoholes are created using local droplet etching (LDE) combining conventional molecular beam epitaxy with self-assembled, lithography-free patterning. The optical emission from single, strain-free QDMs shows clear excitonic features with linewidths below 150 µeV after optimizations of the fabrication process. This allows investigations of the coupling among the individual dots forming a QDM. In electric fields oriented along the axis of the QDM, luminescence emission from direct and indirect transitions can be clearly distinguished. Furthermore, an anti-crossing behaviour demonstrates inter-dot coupling in the QDM.
- Published
- 2017