Not \'interesting\', Big Science.....
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James S said:
So many interesting things both for LED's and regular bulbs. It's going to be a photo finish to see who wins /ubbthreads/images/graemlins/wink.gif Interestingly all of them happening at Sandia.
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This is actually (IMO) an excellent example of 'how it is supposed to work'. We, as a society, invest tax bucks with the goal of just such results. And the American tax payer is getting their money's worth and more. The rest of the world profits as well. This is a good thing.
Yeah, yeah, yeah, so I work for a National Lab (LBNL). I guess I'm not all that objective, but it's still true. At least in my (tiny little) mind.
And it's not 'all happening at Sandia', in fact a large part of 'Gas leads' (slang for Gallium Arsinide LEDs) Materials Science happened where I work, in the Materials Science Division at LBL. Specifically, the National Center for Electron Microscopy where we've done atomic level imaging on the stuff for some years now. And low temp Super Conductors. And high tech alloys. And MEMs stuff. And 'Buckey balls' and carbon nano tubes. And..... Bummer material to work with, hard and brittle and the debris is toxic waste, and we gotta grind it mighty thin (a few dozen atoms thick at most for atomic resolution) to see them ittty bitty atoms.....
Fer instance, here's a micrograph Tom Cass shot on 'my microscope' a few years back of a semi conductor failure mode <
http://ncem.lbl.gov/images/gallery/HVEM device.jpg>. The dislocations (planes of atoms slipping over each other, 'mini cracks' if you will) are the dark lines in the 'main bar' in the upper bar, going right. This is not yet atomic resolution (there are some neat AR shots at <
http://ncem.lbl.gov/frames/gallery.htm> for your viewing pleasure), but can't be as the specimen has to be thicker (a few hundred atoms) to contain the entire Aluminum layer. This is a few microns thick (thousandths of a mm), a 'couple of orders of magnitude too thick' for AR work.
Fun stuff. Big Science every day, and they pay you to do it. Cool.
Doug Owen
