Upconverting Films

Visible-transparent upconverting films consisting of lanthanide-doped metal-oxide nanocrystal (NC) quantum dots functionalized with near-infrared (NIR) and short-wavelength infrared (SWIR) sensitizers will be optimized for integration with polycarbonate optical elements. In Phase I, upconversion was demonstrated using Forster resonant energy transfer (FRET) from NIR/SWIR-sensitive lanthanide complexes to activators doped into the core-shell NC. The goal of the Phase II effort will be to further increase the absorption characteristics and the NIR/SWIR spectral range of the sensitizers while preserving the efficiency of the FRET process and the visible emission. After optimizing the upconverting materials, they will be integrated into thin-film appliques or directly into polycarbonate hosts, and their ability to upconvert images will be demonstrated. The form factor will be equivalent to the lenspiece for ballistic protection goggles. The objectives are to achieve a ballistic goggle lens design that can achieve a visible spectrum transmissivity greater than 70%, when incorporated with the thin-film applique that converts at least three non-visible spectrum bands into different visible spectral wavelengths.