Planar semiconductor membranes with brightness-enhanced embedded quantum dots via electron beam induced deposition of 3D nanostructures: implications for solid state lighting

The engineering of the surrounding photonic environment is one of the most successful approaches routinely used to increase light extraction efficiency and tune the properties of solid state sources of quantum light. However, results achieved so far have been hampered by the lack of a technology that allows for the straightforward fabrication of large scale 3D nano- and microfeatures, with very high resolution and sufficient flexibility in terms of available materials. In this paper we show that Electron Beam Induced Deposition can be a very promising approach to solve this issue, asexemplified by the fabrication of Pt and SiO2 nanofeatures on a membrane containing ordered arrays of site-controlled pyramidal quantum dots. Micro-photoluminescence has been used to compare the emission of the dots before and after the deposition of the structures, remarkably showing both a significant increase in the light extraction efficiency and no degradation of the spectral quality, implying that negligible damage has been caused to the emitter due to the deposition process. This paves the way for novel post-growth processing strategies for epitaxial quantum dots used in both quantum information technologies and lighting applications.