Phospors and LEDs
The benefits of switching to LED lights are becoming well known around the globe. Not only are the energy cost savings significant, the reduced cost of maintaining and replacing light bulbs are also a factor. This also means that as light bulbs do not need to be replaced so often, the impact on the environment is lessened.
How is white light made?
White LED lights are made using a combination of colors and phosphors. Currently, this is being done in two ways.
Mixing color: By mixing different colored LED lights together it is possible to achieve a light that appears white.
Use of phosphors: Applying phosphors to the LED light is currently the most common way to achieve a light that is white in appearance.
The downside of phosphors
The phosphors used in creating white LED light are comprised of rare-earth metals. The majority of these metals are located overseas, primarily in China. In addition, being a rare-earth metal means that there is a finite supply. It becomes problematic for makers of LED lights to label themselves as being better for the environment when they are depleting the earth’s resources.
What is being done?
There is research being done to identify new ways to produce white light. The ORCA project is funded by the German Ministry for Education and Research as part of the “Material Innovations for Industry and Society (WING): Material for Resource-Efficient Industry and Society (MatRessource)” initiative. Their goal is to produce a new formulation for white LED lights.
The quantum dot theory is also being worked on to improve how white LED lights are made. Quantum dots are sub-atomic particles that are used rather than phosphors to produce what some say is the optimal white light. Working with particles on a sub-atomic level however is currently not cost effective for most LED light manufacturers.
www.laserfocusworld.com/articles/2015/08/phosphors-for-white-light-leds-have-no-rare-earth-materials.html; www.laserfocusworld.com/articles/print/volume-42/issue-3/optoelectronics.world/quantam-dot-research-targets-general-illumination.html; www.lrc.rpi.edu/programs/nlpip/lightinganswers/led/whiteLight.asp; www.osram-os.com/osram-os/en/news-events/spotlights/technology/2016/lab-news-rare-earth-reduced-white-leds/index.jsp; www.newatlas.com/fluorescent-light-phosphors-reduce-rare-earth-elements/39859/