Electrical Generation of Colour Centres in Hexagonal Boron Nitride

TL;DR

This paper demonstrates the fabrication of electroluminescent devices in hexagonal boron nitride that generate stable, narrowband colour centres suitable for quantum photonic applications, advancing integration possibilities.

Contribution

It introduces a method to electrically excite and localize colour centres in hBN, enabling their use in quantum photonics without p-n junctions.

Findings

Successful fabrication of hBN electroluminescent devices

Localization of colour centres at tunneling hotspots

Enhanced stability and reduced background emission

Abstract

Defects in wide band gap crystals have emerged as a promising platform for hosting colour centres that enable quantum photonic applications. Among these, hexagonal boron nitride (hBN), a van der Waals material, stands out for its ability to be integrated into heterostructures, enabling unconventional charge injection mechanisms that bypass the need for p-n junctions. This advancement allows for the electrical excitation of hBN colour centres deep inside the large hBN bandgap, which has seen rapid progress in recent developments. Here, we fabricate hBN electroluminescence (EL) devices that generate narrowband colour centres suitable for electrical excitation. The colour centres are localised to tunnelling current hotspots within the hBN flake, which are designed during device fabrication. We outline the optimal conditions for device operation and colour centre stability, focusing on minimising background emission and ensuring prolonged operation. Our findings follow up on the existing literature and mark a step forward towards the integration of hBN based colour centres into quantum photonic technologies.