High Efficiency Multiple Wavelength Upconverting Nanophosphors

Although fluorescent lamps (FLs) convert more input power to visible light than incandescent lamps, even the best of today¿s T-8 FLs convert only about 28% of consumed power into visible radiation. This inefficiency is partially attributed to unwanted infrared emissions (~37%). Therefore, one of the key research efforts is to develop highly efficient up-converting phosphors to collect those wasted IR emissions and convert their radiation into the visible range. This project will develop monodispersed and surface-passivated rare-earth-doped up-converting nanophosphors through a wet chemical process, which has been demonstrated to be cost-effective and reliable in the production of nanocrystals. This approach should be especially favorable for increasing the doping concentration threshold, which is essential for the enhancement of up-conversion efficiency. Commercial Applications and other Benefits as described by the awardee: The up converting phosphors should find use in fluorescent and incandescent lamp applications, not only increasing lamp efficiency and efficacy but also reducing the usage of harmful mercury. Highly-efficient up-converting nanophosphors also could be applied to LEDs for solid-state lighting and to solar energy applications because the solar spectrum has a significant IR component.