Native antisite defects in h-BN

TL;DR

This study uses density-functional theory to identify native antisite defects in h-BN as potential sources of single-photon emission, explaining experimental observations of emission spectra.

Contribution

It reveals that native antisite defects in h-BN can serve as quantum emitters, providing detailed theoretical insights into their optical properties and emission lines.

Findings

Neutral boron antisite may be a nonmagnetic single-photon source at 1.58 eV.

Positively charged nitrogen antisite could be linked to a blue emitter at 2.63 eV.

Out-of-plane phonon modes significantly influence optical properties.

Abstract

Hexagonal boron nitride (hBN) is an excellent host for solid-state single phonon emitters. Experimental observed emission ranges from infrared to ultraviolet. The emission centers are generally attributed to either intrinsic or extrinsic point defects embedded into hBN. Nevertheless, the microscopic structure of most of these defect emitters is uncertain. Here, through density-functional theory calculations we studied the native antisite defects in hBN. We find that the neutral boron antisite might be a nonmagnetic single photon source with zero-phonon-line (ZPL) at 1.58 eV and such a lineshape that is often observed in experiments. Furthermore, the positively charged nitrogen antisite might be associated with a dim color center recently observed as a blue emitter with ZPL at 2.63 eV. These simple single substitution defects indicate the existence of out-of-plane phonon mode which significantly affects the optical properties. Our results could provide useful information for identification of quantum emitters in hBN.