RESUMEN
Deterministically integrating semiconductor quantum emitters with plasmonic nano-devices paves the way towards chip-scale integrable, true nanoscale quantum photonic technologies. For this purpose, stable and bright semiconductor emitters are needed, which moreover allow for CMOS-compatibility and optical activity in the telecommunication band. Here, we demonstrate strongly enhanced light-matter coupling of single near-surface (< 10 nm) InAs quantum dots monolithically integrated into electromagnetic hot-spots of sub-wavelength sized metal nanoantennas. The antenna strongly enhances the emission intensity of single quantum dots by up to ~ 16×, an effect accompanied by an up to 3.4× Purcell-enhanced spontaneous emission rate. Moreover, the emission is strongly polarised along the antenna axis with degrees of linear polarisation up to ~ 85 %. The results unambiguously demonstrate a pronounced coupling of individual quantum dots to state-of-the-art nanoantennas. Our work provides new perspectives for the realisation of quantum plasmonic sensors, step-changing photovoltaic devices, bright and ultrafast quantum light sources and efficient nano-lasers.
RESUMEN
In this work, we study metal droplets on a semiconductor surface that are the initial stage for both droplet epitaxy and local droplet etching. The distributions of droplet geometrical parameters such as height, radius and volume help to understand the droplet formation that strongly influences subsequent nanohole etching. To investigate the etching and intermixing processes, we offer a new method of wetting angle analysis. The aspect ratio that is defined as the ratio of the height to radius was used as an estimation of wetting angle which depends on the droplet material. The investigation of the wetting angle and the estimation of indium content revealed significant materials intermixing during the deposition time. AFM measurements reveal the presence of two droplet groups that is in agreement with nanohole investigations. To explain this observation, we consider arsenic evaporation and consequent change in the initial substrate. On the basis of our analysis, we suggest the model of droplet evolution and the formation of two droplet groups.