Deterministic radiative coupling between plasmonic nanoantennas and semiconducting nanowire quantum dots

TL;DR

This study demonstrates precise coupling of single semiconducting nanowire quantum dots with plasmonic gold nanoantennas, enhancing emission rates and absorption, using a two-step alignment process for nanoscale accuracy.

Contribution

It introduces a deterministic method for coupling quantum dots with plasmonic antennas with 50 nm precision, improving emission and absorption properties.

Findings

Quantum dot emission rate increased up to twofold.

Absorption of nanowires enhanced by antenna coupling.

Precise alignment achieved through cathodoluminescence-based lithography.

Abstract

We report on the deterministic coupling between single semiconducting nanowire quantum dots emitting in the visible and plasmonic Au nanoantennas. Both systems are separately carefully characterized through microphotoluminescence and cathodoluminescence. A two-step realignment process using cathodoluminescence allows for electron beam lithography of Au antennas near individual nanowire quantum dots with a precision of 50 nm. A complete set of optical properties are measured before and after antenna fabrication. They evidence both an increase of the NW absorption, and an improvement of the quantum dot emission rate up to a factor two in presence of the antenna.