GaAs droplet quantum dots with nanometer-thin capping layer for plasmonic applications

摘要

We report on the growth and optical characterisation of droplet GaAs quantumdots with extremely-thin (11 nm) capping layers. To achieve such result, aninternal thermal heating step is introduced during the growth and its role inthe morphological properties of the quantum dots obtained is investigated viascanning electron and atomic force microscopy. Photoluminescence measurementsat cryogenic temperatures show optically stable, sharp and bright emission fromsingle quantum dots, at near-infrared wavelengths. Given the quality of theiroptical properties and the proximity to the surface, such emitters are idealcandidates for the investigation of near field effects, like the coupling toplasmonic modes, in order to strongly control the directionality of theemission and/or the spontaneous emission rate, crucial parameters for quantumphotonic applications.