Highly versatile ultra-low density GaAs quantum dots fabricated by filling of self-assembled nanoholes

摘要

GaAs quantum dots (QDs) of ultra-low density (ULD) are fabricated by filling of nanoholes in AlGaAs surfaces. The holes are drilled using self-assembled local droplet etching with Al droplets. By precisely controlling the arsenic flux and the substrate temperature, the QD density is reduced down to the 106 cm"2 range uniformly over the whole wafer. The QD size is precisely adjustable via the hole filling level. By this, the optical emission energy of the QDs can be adjusted over a wide energy range of at least 120 me V. The surface visibility of ULD QDs allows their simple integration into lithographic processing.