Quantum Dot Based Optical Taggants for Combat Identification

ABSTRACT: Physical Sciences Inc. (PSI) proposes to develop a passive optical taggant that utilizes the absorptive and emissive properties of colloidal quantum dots (QDs). The device will be a flexible, robust, and low-cost QD composite that is deployable on vehicles and soldiers. The taggant device will emit from 3.9-4.1 um with quantum yields>30% when excited by standard military laser designators. Preliminary feasibility calculations indicate the capability of detecting emitted photons from the proposed QD taggant with a FLIR camera from ranges up to 2 km. During Phase I, we will develop the synthetic conditions to produce QDs with the correct diameters and optimized quantum yields. We will use in-house lasers to excite the prepared quantum dots to demonstrate optimum emission wavelengths and quantum yields, as well as show detectability using a Mid-wave Infrared focal plane array. In Phase II we will develop polymer/QD packaging and produce deployable prototypes that will be extensively tested in realistic environments. In the Phase II program, PSI will scale up the optimized QD preparation developed in Phase I and work with a thin film manufacturer to develop roll-to-roll production of QD taggant devices. At the end of Phase II, we anticipate a TRL 6 capability. BENEFIT: A quantum dot based optical taggant will advance military combat identification because it does not require power and it can emit at precisely designed wavelengths in the Mid-wave Infrared (MWIR) spectral region. The proposed quantum dot taggants are well suited as passive components in emerging imaging based Blue Force Tracking Systems.