The LED's Dark Secret: "droop"
spectrum.ieee.org
spectrum.ieee.org
They're well-written and seem to be scientifically accurate - a rarity on the web these days.
If someone points out that we don't know how to do this within certain price & size constraints, then I reply, fine, that's a problem to solve. So is droop. Solving either one of these problems get us the lighting we want. Is there any reason to single out droop as the problem that must be solved?
As physicists we are interested in the droop problem because it is more fundamental to the structure and intrinsic nature of semiconductors and solids in general. It is along the same lines of: if we have type-2 superconductors that work at liquid nitrogen, why do we keep looking for SCs that work at room temperature, or if we have type-1 superconductors, why do we need type-2?
From a purely pragmatic point of view we know that more LEDs leads to the use of more money, more time, and more materials. A more efficient LED is a wise idea. I believe you may be missing a link here, that droop, or its physical cause, IS the entire problem that causes strains on price and size constraints. This is the reason to single it out.
Maybe the result would be too big to be practical. Or too expensive.
I could also get 'High-Power' led-bulbs, filled with only 3 - 10 LEDs and producing the same amount of lumen but they all had a higher power consumption than the 80-led bulbs and strangely where more expensive (this probably has to do with heat removal requiring big heat sinks).
This sounds like an engineering problem that will be solved (or at least mitigated). I remember how a few years ago we were told that silicon processes were nearing their limits, and then engineers figured ways to get around some of the perceived hard walls.
According to wikipedia - http://en.wikipedia.org/wiki/Light-emitting_diode
Where in NY is a good spot to shop for LED lights?
Although if you want super bright, go for the 10mm 100000mcd+ ones off ebay, 50 of them easily replaces a 70W light. I bought 1000 of them, cheap in bulk, and their a lot of fun. If you're making your own LED series don't forget to add resistor to limit the current.
I've been putting in LED spots for my office (instead of 25W halogen MR16 lights). I've tried some off of ebay that (claim to) have Luxeon or Nichia LEDs. I've also gotten some from http://www.ledwaves.com/. All are pretty nice, but I haven't decided what color temp I like so currently there's a mishmash of cool and warm ones...
I have seen led lights - but they all are extremely expensive. If you want to use to replace incandecent bulbs, CFLs would be a lot cheaper (IMHO).
Some of my friends built their own lighting system and they ordered the LEDS directly from a mail order electronics store. This would probably be the cheapest.