# Luminescent defects in a few-layer h-BN film grown by molecular beam epitaxy

## TL;DR

This study investigates luminescent defects in few-layer h-BN films grown by molecular beam epitaxy, identifying potential defect types and their optical properties, with implications for quantum light source applications.

## Contribution

The paper provides the first detailed analysis of luminescent centers in MBE-grown h-BN, linking specific defect types to observed luminescence features.

## Key findings

- Luminescent centers localized within microscopic islands
- Identification of N_BV_N anti-site as a potential emitter
- Evidence of defects involving carbon or oxygen

## Abstract

We report on luminescent centers contained in a few-layer-thick hexagonal boron nitride (h-BN) film grown on Ni by molecular beam epitaxy. After transfer to a SiO$_2$/Si substrate, sharp lines are observed in photo- and cathodoluminescence spectra in both the ultraviolet and the visible range. Spatially resolved measurements reveal that the luminescent centers responsible for these lines are localized within microscopic multi-layer islands that form at the nucleation centers of the h-BN film. The comparison of their energy, polarization and phonon replica emission with previous theoretical predictions suggest that the N$_\mathrm{B}$V$_\mathrm{N}$ anti-site could be one of the light emitters present in our sample. Moreover, we have also observed evidences of other kinds of centers that could be associated to defects containing carbon or oxygen. The characterized luminescent defects could have potential applications as quantum light sources.