Bret Cannon said:
Look up the SUVOS program funded by DARPA. Its aim was to develop UV LEDs
for various biological sensing applications. As I recall 350 nm and 280 nm
were their target wavelengths because each wavelength is good for exciting a
certain class of biological molecules. I don't think that a wavelength as
short as 254 nm was thought possible, but they made a lot of progress.
Bret Cannon
Here's an exerpt from one of the docs I dug up with a SUVOS search.
Some inetesting info about LEDs saving electricity, fuel, etc.
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The U.S. Department of Energy released two studies that analyzed and
estimated energy savings of solid-state lighting (mainly
LEDs). One study estimated the energy savings potential if solid-state
lighting can achieve certain price and performance criteria.
The report considered two scenarios—one where the technology receives a
moderate national investment of $50 million per year and
an accelerated scenario based on an investment of $100 million per year.
Under the moderate investment scenario, in 2025, the energy
savings associated with solid-state lighting could total approximately
114 terawatthours (TWh) or the equivalent annual electrical
output of about 14 large powerplants. Under the accelerated investment
scenario, in 2025, the total energy savings could be about 326
TWh, representing the output of more than 40 large powerplants (Navigant
Consulting Inc., 2003b§1).
....
The second study that looked at LED use in niche applications concluded
that LED traffic signals use only 10% of the electricity
consumed by the incandescent lamps they replace, and they last much
longer, allowing for additional savings through reduced
maintenance costs. Exit signs were identified as another important niche
application, where an estimated 80% of U.S. exit signs now
use LEDs. LEDs also have made inroads into mobile applications, such as
brake and signal lights on automobiles, buses, and trucks.
To date, 41 million gallons per year of gasoline and 142 million gallons
per year of diesel fuel have been saved because of LED use on
these vehicles. (Fuel savings were calculated based on the lower
accessory load on the engine.) If all automobiles, buses, and trucks
were to convert to LED lighting, 1.4 billion gallons per year of
gasoline and 1.1 billion gallons per year of diesel fuel could be saved
(Navigant Consulting Inc., 2003a§).