Single-Photon Emission from Point Defects in Aluminum Nitride Films

Area of Science:

• Materials Science
• Quantum Physics
• Solid-State Physics

Background:

• Robust and photostable single-photon emitters are essential for advancing quantum technologies.
• Defect-based emitters in wide-bandgap semiconductors are promising candidates for quantum applications.

Purpose of the Study:

• To report room-temperature single-photon emission from isolated defects in aluminum nitride (AlN) films.
• To investigate the optical properties and identify the physical origin of these emissions.
• To explore the potential of AlN as a platform for on-chip quantum sources.

Main Methods:

• Growth of AlN films on nanopatterned sapphire substrates using metal-organic chemical vapor deposition (MOCVD).
• Characterization of optical emission lines, including spectral range, polarization, and temperature-dependent linewidth.
• First-principles calculations using density functional theory (DFT) to identify defect structures responsible for emission.

Main Results:

• Observation of single-photon emissions from isolated defects in AlN films operating at room temperature.
• Emission lines observed across the visible to near-infrared spectrum (approx. 550-1000 nm) with highly linear polarization.
• Temperature-dependent linewidth analysis revealed T³ or single-exponential behavior.
• DFT calculations identified antisite nitrogen vacancy (N_AlV_N) and divacancy (V_AlV_N) complexes as likely origins of the observed emissions.

Conclusions:

• Aluminum nitride (AlN) films host isolated defects capable of room-temperature single-photon emission.
• These AlN-based emitters exhibit desirable optical properties for quantum applications.
• The identified defect centers provide a fundamental understanding and a new platform for developing on-chip quantum sources.