This Small Business Innovation Research (SBIR) Phase I Project will develop the next generation quantum dot-based security features that will have unique visible and infrared fluorescent characteristics. The project combines recent advances in semiconductor nanocrystals (quantum dots) and microresonant structures to produce truly novel and spectrally tunable barcoded taggants for advanced security applications that are nearly impossible to counterfeit, duplicate or reverse-engineer. The proposed taggant will be designed to be compatible with inks, UV curable epoxies, and polymers currently used on currencies and other documents and laminates. In the project, it is proposed to disperse fluorescent quantum dots within a resonant structure (thin film interference structure), micromize the resultant resonator, and disperse the micronized particles within the suitable ink and laminate matrices. Commercially, successful completion of this project would have great impact in the security market. Presently all conventional taggants have been compromised to one degree or other. This technology will provide an added shield against those who wish to do harm to this country and others through the counterfeiting of currencies, passports, and other secure documents and identifications. Knowledge gained on the fabrication of nanocrystal composite thin films with controlled thicknesses and in particular nanocrystals films in resonant cavities would have great impact on fields beyond security. In particular that technology would have potential applications in a number of photonic applications including lasers as well as optical switching and other nonlinear optical components
