Masters defense: Laurits Moestrup Høgel

Positioned InAs Quantum Dots from Selective Area Growth

Indium-Arsenide quantum dots are widely used in platforms for quantum pho- tonics and serve as single photon sources and non-linear components. Commonly, Stranski-Krastanov quantum dots are used, but using instead MBE Selective Area Growth, the quantum dots can be positioned and tuned deterministically.
InAs quantum dots were grown on buffered GaAs (100) substrates, and character- ized through AFM, SEM, TEM and PL. In parallel, simulations were done on MBE adatom dynamics, equilibrium crystal shapes, interface strain, and electronic con- finement energy. It was observed that the GaAs buffer growth is highly dependent on a proximity effect. The InAs growth occurs exclusively on top facets. The task remains to grow elastically strained InAs quantum dots which requires utilisation of the structures near the lower MBE limit for spatial dimensions.
While the optimal calibration is yet to be reached, the proof of concept is estab- lished that buffered SAG can provide a deterministic path for InAs quantum dot manufacturing.