Direct visualization and effects of atomic-scale defects on the optoelectronic properties of hexagonal boron nitride

TL;DR

This study directly visualizes atomic-scale defects in hexagonal boron nitride and links them to single-photon emission properties, advancing understanding of defect-related optoelectronic behavior for quantum tech applications.

Contribution

It provides the first direct atomic-scale visualization of defects in hBN and correlates these structures with their optical emission properties using combined microscopy and theoretical analysis.

Findings

Atomic-scale defects visualized with atomic force microscopy.

Multiple narrow emission lines observed from stable emitters.

Defects linked to specific single-photon transitions.

Abstract

Hexagonal boron nitride (hBN) is attracting a lot of attention in the last years, thanks to its many remarkable properties. These include the presence of single-photon emitters with superior optical properties, which make it an ideal candidate for a plethora of photonic technologies. However, despite the large number of experimental results and theoretical calculations, the structure of the defects responsible for the observed emission is still under debate. In this work, we visualize individual atomic-scale defects in hBN with atomic force microscopy under ambient conditions and observe multiple narrow emission lines from optically stable emitters. This direct observation of the structure of the defects combined with density functional theory calculations of their band structures and electronic properties allows us to associate the existence of several single-photon transitions to the observed defects. Our work sheds light on the origin of single-photon emission in hBN that is important for the understanding and tunability of high-quality emitters in optoelectronics and quantum technologies.