Structural attributes and photo-dynamics of visible spectrum quantum emitters in hexagonal boron nitride

TL;DR

This study explores the structural and photodynamic properties of quantum emitters in hexagonal boron nitride, revealing their stability, spectral features, and potential for quantum sensing and photonics.

Contribution

It demonstrates how fabrication methods like etching and irradiation create stable quantum emitters in h-BN and links their properties to structural features and defect orientations.

Findings

Emitters are stable at room temperature in UV and visible range.

Spectral features are influenced by interaction with a Raman active mode.

Emitters exhibit diverse photodynamic rates and excellent stability.

Abstract

Newly discovered van der Waals materials like MoS$_2$, WSe$_2$, hexagonal boron nitride (h-BN), and recently $\mathrm{C}_2\mathrm{N}$ have sparked intensive research to unveil the quantum behavior associated with their 2D structure. Of great interest are 2D materials that host single quantum emitters. h-BN, with a band gap of 5.95 eV, has been shown to host single quantum emitters which are stable at room temperature in the UV and visible spectral range. In this paper we investigate correlations between h-BN structural features and emitter location from bulk down to the monolayer at room temperature. We demonstrate that chemical etching and ion irradiation can generate emitters in h-BN. We analyze the emitters' spectral features and show that they are dominated by the interaction of their electronic transition with a single Raman active mode of h-BN. Photodynamics analysis reveals diverse rates between the electronic states of the emitter. The emitters show excellent photo stability even under ambient conditions and in monolayers. Comparing the excitation polarization between different emitters unveils a connection between defect orientation and the h-BN hexagonal structure. The sharp spectral features, color diversity, room-temperature stability, long-lived metastable states, ease of fabrication, proximity of the emitters to the environment, outstanding chemical stability, and biocompatibility of h-BN provide a completely new class of systems that can be used for sensing and quantum photonics applications.