Nano-aperture plasmonic VCSELS

We have successfully investigated the selfassembly mechanism for InAs quantum dots (QDs) formed on GaAs(001) by using a unique scanning tunnelling microscope (STM) placed within the molecular beam epitaxy (MBE) growth chamber. The images elucidate the mechanism of QD nucleation, demonstrating directly that not all deposited In is initially incorporated into the lattice, hence providing a large supply of material to rapidly form QDs via islands containing tens of atoms. kinetic Monte Carlo (kMC) simulations based on firstprinciples calculations show that tiny alloy fluctuations, like atomistic point defects, in the InGaAs wetting layer prior to are crucial in determining nucleation sites.