Advanced Phosphor Technologies For Energy Efficient Lighting And Energy Harvesting

Fluorescent and incandescent lighting consumes more than 50% of the lighting energy budget. However, these technologies are relatively inefficient, losing approximately 37% and 85%, respectively, of their energy to IR, rather than visible, frequencies. Efficient IR-to-visible upconversion phosphors could have a significant impact on lamp efficiency and design. This project will develop Concentrically Doped Upconverting Nanophosphors (CDUN) to increase the efficiency of upconversion phosphors by more than an order of magnitude. In this approach, both sensitizer and activator doping will be conducted in two-dimensional (2-D) shells, dramatically enhancing upconversion efficiency while simultaneously reducing sensitizer-defect interactions. Unwanted radiative losses will be inhibited by incorporating the nanophosphers into photonic crystal structures. Phase I will further develop the CDUN theory and demonstrate the synthesis of monodispersed nanophosphors with highly controlled doping. This task will be followed by the synthesis of 2-D concentrically doped layers separated and capped by the undoped host lattice. Commercial Applications and other Benefits as described by the awardee: The nanophosphors should be applicable to all existing lamp products including incandescent, tungsten-halogen, and all types of fluorescents lamps, and would ignite new approaches to enhancing solid state lighting. Moreover, because the solar spectrum has a significant IR component, the technology could be used to fold this energy into the visible region, significantly improving solar cell efficiency. Potentially, the new nanophosphor technology could result in an annual national energy savings of 0.979 quads.