Multispectral Quantum Dot Tags for Advanced Anticounterfeiting Applications.

Area of Science:

• Nanophotonics and Materials Science
• Quantum Dot Technology
• Information Security

Background:

• Physical unclonable functions (PUFs) are crucial for secure authentication.
• Existing luminescent PUFs often lack sufficient uniqueness and entropy.
• Nanophotonic materials offer potential for advanced PUF development.

Purpose of the Study:

• To develop a novel quantum dot (QD)-driven optical fingerprinting platform for secure authentication.
• To leverage multi-peak photoluminescence (PL) from cadmium-free QDs for high-entropy fingerprint generation.
• To establish a foundation for next-generation optical authentication technologies.

Main Methods:

• Utilized two cadmium-free CIS/ZnS QD formulations exhibiting dual-peak PL emission.
• Implemented multiwavelength excitation to generate a combined four-peak spectral profile.
• Extracted spectral features (wavelength, FWHM, intensity) across nine excitation wavelengths.
• Applied a feature fusion strategy to convert spectral data into a 216-bit binary fingerprint.

Main Results:

• Achieved a high degree of uniqueness with a mean inter-Hamming distance of 0.512 ± 0.028.
• Demonstrated a wide collision margin (99-123 differing bits) and near-zero intra-tag variation.
• Confirmed near-ideal statistical behavior and bit-level randomness after binarization.
• The four-peaks architecture significantly advances over single or dual-peak luminescent PUFs.

Conclusions:

• The QD-driven optical fingerprinting platform provides dense, high-entropy, and unique identifiers.
• Cadmium-free materials are effectively utilized, enhancing safety and sustainability.
• The developed four-peaks architecture is compatible with standard readout hardware, paving the way for practical optical authentication.