Light Emitting Diode Coating Can Drive Down White LED Light Prices
Scientists in the US created a new light emitting diode (LED) coating from a relatively inexpensive metal organic framework (MOF) in the form of a film coating. This new alternative may be used as an alternative to existing white LED coatings, which are made of more expensive rare elements.
LED lighting has increasingly become a more attractive alternative to traditional incandescent and halogen lighting. As LED technology continues to improve to reach a more attractive price point, one of the greatest challenges involves inexpensively producing white LED lighting owners and tenants desire. Pure white LED light does not exist, and must be created from a combination of several different colors such as red, green, and blue. An alternative to using these multi-chip LEDs is for engineers to use a single blue chip. The blue chip light is then converted to white light through a yellow phosphor coating.
Phosphors used in the coatings are any substance that illuminates when exposed to light. Phosphor based LEDs are typically created from yttrium, europium, and terbium. From 2001 to 2011, the cost of these elements have risen by 400%, 600%, and 1600%, making the production of LEDs more and more expensive.
The MOF developed by the team from Rutgers University combines a common molecular chromophore, tetrakis (4-carboxyphenyl)ethylene, with zinc cations. An additional benefit of the MOF is that it can produce white light of different wavelengths by modifying the structure. The next step for the MOF is to determine how the new coating will be inserted into current manufacturing operations.