Electrically driven optical metamaterials

Quynh Le-Van,Aloyse Degiron,Abdelhanin Aassime,Xavier Le Roux

doi:10.1038/ncomms12017

Abstract

The advent of metamaterials more than 15 years ago has offered extraordinary new ways of manipulating electromagnetic waves. Yet, progress in this field has been unequal across the electromagnetic spectrum, especially when it comes to finding applications for such artificial media. Optical metamaterials, in particular, are less compatible with active functionalities than their counterparts developed at lower frequencies. One crucial roadblock in the path to devices is the fact that active optical metamaterials are so far controlled by light rather than electricity, preventing them from being integrated in larger electronic systems. Here we introduce electroluminescent metamaterials based on metal nano-inclusions hybridized with colloidal quantum dots. We show that each of these miniature blocks can be individually tuned to exhibit independent optoelectronic properties (both in terms of electrical characteristics, polarization, colour and brightness), illustrate their capabilities by weaving complex light-emitting surfaces and finally discuss their potential for displays and sensors.

Highlights

The advent of metamaterials more than 15 years ago has offered extraordinary new ways of manipulating electromagnetic waves
The all-inorganic architecture of our metamaterials is derived from the quantum dot light-emitting diodes (QLEDs)[12,13,14] and photovoltaic cells[15] developed as cheaper and more versatile alternatives to epitaxial optoelectronic components[16]
We explain why a Au nanoparticle array coated with colloidal quantum dots (CQDs) qualifies as a genuine artificial active medium

Summary

Introduction

The advent of metamaterials more than 15 years ago has offered extraordinary new ways of manipulating electromagnetic waves Progress in this field has been unequal across the electromagnetic spectrum, especially when it comes to finding applications for such artificial media. Electrically driven structures can be implemented by incorporating lumped electronic elements in the metamaterial architecture[10] or by forming Schottky contacts between metallic unit cells and a semiconducting substrate[11]. In the optical regime lumped elements are too big compared with the wavelength and alternative implementations must take into account that the electrodes needed to inject an electrical signal occupies a much larger footprint than the metamaterial inner structure and may perturb its properties or prevent light from properly interacting with it. We demonstrate the concepts with infrared LEDs exhibiting a form of discrete artificial electroluminescence (EL)

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Conclusion