Discovering new phosphors for lighting

Discovering new phosphors for lighting

The Critical Materials Institute (CMI) along with GE and Lawrence Livermore and Oak Ridge National Laboratories has discovered new phosphors for use in efficient lighting technologies, such as fluorescent long tube lighting and LEDs.  CMI has developed an accelerated materials discovery framework that predicts which new materials have the characteristics needed for lighting applications and scales up the production of these materials for manufacturing trials.

Phosphors for lighting applications often contain critical rare earth materials, such as europium and terbium, which are subject to supply risk.  CMI’s accelerated materials discovery process can identify new phosphors that meet or exceed existing materials in both manufacturing and performance in fluorescent and LED lamps.  Current LED technology, for example, is limited in its ability to provide “tunable” color for lamps because the phosphors used are broadband emitters, which results in blue color.  This “cool light” is less marketable in the North American market, where consumers prefer yellow-toned lighting.

CMI utilized both rapid computational and experimental discovery methods to identify materials with appropriate emissive qualities -- they emit light at the right wavelength and have narrow bandwidth emissions necessary for LED applications.  These methods allowed for quick screening of viable candidates, taking into account manufacturing requirements.  Within in a two-year span, this approach helped scientists rapidly identify replacements for red and green phosphors in fluorescent lamps, eliminating the use of europium and terbium.  The process was then extended to LED phosphors, and within the first year and a half of that effort, CMI scientists identified viable candidates for replacements for both red and green phosphors in LED lighting with narrow bandwidth. 

CMI brings scientists from across the DOE laboratory complex together to solve multidisciplinary problems.  These projects are significant in scope and often utilize a method that integrates computational and experimental methods to rapidly screen candidate substitute materials.  The framework and methodology used is broadly applicable beyond lighting technology and is being used for materials discovery and design in other areas, such as permanent magnet materials.  This capability can be extended to other critical materials whose supply risk can be addressed through the use of alternative materials.