Planar Semiconductor Membranes with Brightness Enhanced Embedded Quantum Dots via Electron Beam Induced Deposition of 3D Nanostructures: Implications for Solid State Lighting

Abstract

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, as exemplified by the fabrication of Pt and SiO 2 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.

Towards 3D characterisation of site-controlled InGaAs pyramidal QDs at the nanoscale

“…In order to improve the odds of correctly locating the dots, some PQD samples were further processed to obtain pillars using a top-down process [ 34 ]. This was achieved by depositing a 300 nm thick SiO 2 hard mask via sputtering and, by exploiting the 3-dimensionality of the system, exposing the GaAs using chemo-mechanical planarization (CMP) [ 35 ], while leaving some SiO 2 on top of the structure, as shown in Fig. S1.…”