Identifying Luminescent Boron Vacancies in h-BN Generated Using Controlled He⁺ Ion Irradiation

Area of Science:

• Materials Science
• Quantum Photonics
• Solid State Physics

Background:

• Defect emission in hexagonal boron nitride (h-BN) at 1.55 eV is crucial for optical spin readout.
• Controlled introduction of point defects in h-BN is challenging without altering its atomic structure.

Purpose of the Study:

• To controllably introduce boron vacancies in h-BN.
• To achieve robust photoluminescence emission at 1.55 eV.
• To enable scalable quantum photonics applications.

Main Methods:

• Controlled introduction of boron vacancies using a low-energy He+ ion beam with ultrahigh spatial resolution.
• Optimization of He+ ion irradiation conditions to control defect quantity and location.
• Characterization using photoluminescence spectroscopy and electron energy loss spectroscopy (EELS).

Main Results:

• Achieved robust photoluminescence emission at 1.55 eV from 10 K to room temperature.
• Demonstrated control over defect spatial distribution and depth.
• Identified a new Raman mode at 1295 cm-1 associated with boron vacancies.
• Confirmed the introduction of boron vacancies without modifying the local h-BN crystal structure via EELS.

Conclusions:

• Developed a deterministic strategy for creating scalable boron vacancy emitters in h-BN.
• The method enables precise engineering of point defects for quantum applications.
• This work paves the way for advanced quantum photonic devices based on h-BN.