High-Capacity Optical Fingerprinting Using Dual-Peak Photoluminescence of Quantum Dots

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Counterfeiting and unauthorized duplication present significant global economic and safety risks.
• Existing anticounterfeiting technologies often face challenges in terms of clonability and security.

Purpose of the Study:

• To develop a novel, highly secure, and unclonable optical fingerprinting platform for anticounterfeiting applications.
• To utilize the unique photoluminescence properties of cadmium-free quantum dots for generating secure digital fingerprints.

Main Methods:

• Synthesis of cadmium-free copper indium sulfide/zinc sulfide (CuInS2/ZnS) core/shell quantum dots (QDs).
• Characterization of QD photoluminescence (PL) with a distinctive dual-peak signature using time-resolved PL (TRPL) analysis.
• Development of a spectral-to-digital processing method to extract features from QD emissions under multiple excitation wavelengths.

Main Results:

• Demonstrated a novel optical fingerprinting platform based on CuInS2/ZnS QDs with intrinsically coupled dual-peak PL emissions.
• Confirmed distinct recombination origins for the dual peaks, attributing them to core and interfacial/shell states.
• Generated binary fingerprints with a theoretical encoding capacity of 1.2 × 10^18 and an experimental error probability of ~3 × 10^-17.

Conclusions:

• The proposed QD-based optical fingerprinting system offers a highly secure and unclonable solution for anticounterfeiting.
• The dual-peak PL signature and spectral-to-digital processing provide a robust mechanism for product authentication.
• This technology holds significant potential for practical implementation in diverse industries to combat counterfeiting.