Solvent-Exfoliated Hexagonal Boron Nitride Nanoflakes for Quantum Emitters

Abstract

Quantum emitters in hexagonal boron nitride (hBN) flakes have recently emerged as a promising platform for nanophotonic and quantum applications. The solvent-exfoliation process of these flakes has, however, remained largely unexplored. In this work, we demonstrate a surfactant-assisted exfoliation technique in an aqueous solution to exfoliate a variety of commercially available hBN powders into hBN nanoflakes. We show that the selection of hBN powder greatly impacts the optical properties of the resultant quantum emitters embedded in exfoliated hBN nanoflakes. We find that the sample with the best optical performance also shows the lowest impurity levels in its starting hBN powder. Our study provides further insight into quantum emitter fabrication in hBN and tailoring of their optical properties.

Coherent control of an ultrabright single spin in hexagonal boron nitride at room temperature

“…1c, exhibiting that the single hBN flake can be isolated effectively. The hBN flakes originally host the optically-active defects [38][39][40][41][42][43], and this process increases the possibility to isolate the single nano-flake with single spin defect, instead of cluster of flakes. See experimental section for the details of the sample preparation process.…”

Laser Direct Writing of Visible Spin Defects in Hexagonal Boron Nitride for Applications in Spin-Based Technologies

“…We speculate that this method produces a variety of different defects, and the further cryogenic spectra of these defect ensembles give corresponding evidence (Figure S10 in the Supporting Information). This can be attributed to the complex process of high-energy laser irradiation and chemical bond recombination, in which not only native defects such as vacancies, antisite defects, and interstitial defects are generated but also the doping defects formed by the original atoms in hBN flakes 28 or even laserionized atoms in air. In the mean time, the varying degrees of damage by laser writing, the uneven distribution of impurities in hBN flakes, and the statistical nonuniformity of the small defect ensemble jointly contribute to the different proportion of spectral peaks (Figure S5b in Supporting Information).…”

“…Optically addressable spin defects in wide band gap materials are available for applications in quantum information − and quantum sensing. − , Besides solid-state spins in diamond − and silicon carbide, − hexagonal boron nitride (hBN)a van der Waals material with a wide band gap (∼6 eV) and excellent scalability to host on-chip systems , has been reported to have optically active spin defects. Since Tran et al first discovered single-photon emission in monolayer hBN at room temperature, research into quantum emitters in hBN began to flourish. − So far, there have been several spin defects found with optically detected magnetic resonance (ODMR) signals in hBN, indicating the great potential of hBN in quantum technology. However, for most spin defects, we have not yet mastered the technology for controllable fabrication.…”

Laser Direct Writing of Visible Spin Defects in Hexagonal Boron Nitride

“…At the mean time, the ensemble is not large enough to become statistically uniform, giving different proportion of spectral peaks (Figure S4 in Supporting Information). This can be attributed to the complex process of high-energy laser irradiation and chemical bond recombination, in which not only native defects such as vacancies, antisite defects and interstitial defects are generated, but also the doping defects formed by the original atoms in hBN flakes [26] or even laser-ionized atoms in air. Further study of defect species is beyond the scope of this paper and requires more research in the future.…”

“…Besides solid-state spins in diamond [9][10][11][12] and silicon carbide [13][14][15][16][17][18], hexagonal boron nitride (hBN) -a van der Waals material with wide bandgap (∼ 6 eV) and excellent scalability to host on-chip systems [19,20] -have been reported to have optically active spin defects. Since Tran et al [21] first discovered single photon emission in monolayer hBN at room temperature, research into quantum emitters in hBN began to flourish [22][23][24][25][26]. So far, there have been found several spin defects with optically detected magnetic resonance (ODMR) signal in hBN, indicating the great potential of hBN in quantum technology.…”