Observation and Spectral Assignment of a Family of Hexagonal Boron Nitride Lattice Defects

Abstract

Atomic vacancy defects in single unit cell thick hexagonal boron nitride are of significant interest because of their photophysical properties, including single-photon emission, and promising applications in quantum communication and computation. The spectroscopic assignment of emission energies to specific atomic vacancies within the triangular lattice is confounded by the exponential scaling of defect candidates with the number of removed atoms. Herein, we collect more than 1000 spectra consisting of single, isolated zero-phonon lines between 1.69 and 2.25 eV, observing 6 quantized zero-phonon lines arising from hexagonal boron nitride vacancies. A newly developed computational framework for isomer cataloguing significantly narrows the number of candidate vacancies. Direct lattice imaging of hexagonal boron nitride, electronic structure calculations, and subsequent boric acid etching are used to definitively assign the 6 features. Systematic chemical etching supports the assignment by demonstrating the sequence of growth of successively larger vacancy centres from smaller ones, with the defects including a single B vacancy and a 16-atom triangular defect. These features exhibit a range of emission lifetimes from 1 to 6 ns, and phonon sidebands offset by the dominant lattice phonon in hexagonal boron nitride near 1370 cm-1. This assignment should significantly advance the solid-state chemistry and photophysics of such vacancy emitters.

arXiv comment28 pages, 5 figures, and 40 pages of supplementary information

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Cited by in corpus (4)

• First-principles identification of single photon emitters based on carbon clusters in hexagonal boron nitride
• Vibrational signatures for the identification of single-photon emitters in hexagonal boron nitride
• How Grain Boundaries and Interfacial Electrostatic Interactions Modulate Water Desalination Via Nanoporous Hexagonal Boron Nitride
• Photo-Physical Characteristics of Boron Vacancy-Derived Defect Centers in Hexagonal Boron Nitride