Gold Quantum Rods Emit in the Shortwave Infrared (1000-2200 nm) with 10^4-5 M^-1 cm^-1 Ultrabrightness

Area of Science:

• Materials Science
• Nanotechnology
• Optical Physics

Background:

• Near-infrared-II (NIR-II) or shortwave infrared (SWIR) fluorescence is crucial for advanced optical applications.
• Developing bright, stable, and tunable SWIR emitters remains a significant challenge.

Purpose of the Study:

• To report ultrabright, subnanosecond fluorescence emission in the SWIR region.
• To establish atomically precise gold quantum rods (Au QRs) as a new benchmark platform for SWIR emitters.

Main Methods:

• Synthesized atomically precise gold quantum rods (Au QRs).
• Optimized Au QRs to suppress singlet-to-triplet exciton conversion and electron-vibration coupling.
• Transferred Au QRs into aqueous phase using Pluronic F-127 polymer wrapping.

Main Results:

• Achieved ultrabright fluorescence emission spanning 1000 to 2200 nm.
• Reported quantum yields up to ~21% and unprecedented brightness exceeding state-of-the-art SWIR organic dyes.
• Demonstrated successful aqueous phase transfer of Au QRs.

Conclusions:

• Atomically precise Au QRs redefine brightness and spectral reach in SWIR fluorescence.
• Au QRs provide a foundation for next-generation SWIR photonic and biorelated technologies.
• This work overcomes key limitations in SWIR emitter development.