Room temperature electroluminescence from isolated colour centres in van der Waals semiconductors

TL;DR

This paper reports the first demonstration of room temperature electroluminescence from isolated colour centres in hexagonal boron nitride, using nanoscale graphene-hBN-graphene tunnel junctions to enable efficient electrical excitation.

Contribution

It introduces a novel device architecture that achieves room temperature electroluminescence from hBN colour centres, advancing integrated quantum photonic technologies.

Findings

Operates at room temperature with stable emission

Produces narrowband light from visible to near infrared

Uses graphene-hBN-graphene tunnel junctions for excitation

Abstract

Defects in wide bandgap semiconductors have recently emerged as promising candidates for solid-state quantum optical technologies. Electrical excitation of emitters may pave the way to scalable on-chip devices, and therefore is highly sought after. However, most wide band gap materials are not amenable to efficient doping, which in turn poses challenges on efficient electrical excitation and on-chip integration. Here, we demonstrate for the first time room temperature electroluminescence from isolated colour centres in hexagonal boron nitride (hBN). We harness the van der Waals (vdW) structure of two-dimensional materials, and engineer nanoscale devices comprised of graphene - hBN - graphene tunnel junctions. Under an applied bias, charge carriers are injected into hBN, and result in a localised light emission from the hBN colour centres. Remarkably, our devices operate at room temperature and produce robust, narrowband emission spanning a wide spectral range - from the visible to the near infrared. Our work marks an important milestone in van der Waals materials and their promising attributes for integrated quantum technologies and on-chip photonic circuits.