another breakthrough, aren't we up to about 600% efficency now?

for once I agree -- for once I woulld like to see a solar cell make of all the coating that we have heard of in the last 4 years be made into a solar cell and an effeincy number given -- it is always this could work and scientists say improving it should be very straight forward -- it almost never works and if it does improving is never straight forward

If they can harness 2 electrons per photon then why wouldn't they be able to double the efficiency? An improved efficiency of 5% seems underrated for this development.

Solar energy is a great field to find examples of how lab experiments look great but in practice it doesn't hold up. I imagine various reasons can be cited, like unable to bring costs down when scaling up production. Unable to maintain efficiency (materials degrade) for an acceptable length of time.

And my *FAVORITE* reason: "Oh, we sold the process/patent to a major maker of panels that needed to squash it lest their capitol investments in old technology has to be written off as a loss.

There's a little too much pessimism on this thread. In practice, PV have steadily been getting cheaper and more efficient. I fully expect to install solar panels on my roof within the next five years, and my first panels may very well incorporate this 'excitonic" coating.

I guess most folks here haven't the foggiest idea what advances in practical manufacturing and assembly will need to be fool proofed before these advanced materials coating and entirely new and cost effective assemblies reach the consumer/commerical markets.

Remember, in a world of today that expects 40% profit margins to not be ridiculed and buried by hedge fund managers some serious decisions will need to be made to insulate against such ignorance.

Well, they say they busted the theoretical limit of 34% (blow past it like a jet thru the sound-barrier, I believe it was worded) but he summated that with their new technique it was conceivable to achieve 30% with panels using it.
Am I missing something here?

Wayyy too much cynicism here. What, researching into renewables is worthless because of the challenges? Name me something we perfected on the first try. Of course there's going to be a lot of baby steps, of course a lot of things aren't going to pan out, of course some things that look great on paper don't end up working. This is true of every single field of research, don't nit-pick on solar. Keep in mind, we weren't interested in longevity, maintenance costs or materials needed, efficiency ratings and so on, when designing other power sources, only the power output for the cost. We are, essentially, trying to make the perfect solar cell, without the generations of products being replaced. We don't want to go from vinyls to 8 tracks to cassettes to CDs to MP3, we just want the best cell we can make, BEFORE we invest millions or billions installing it around the world. Be glad we're trying so hard, and that such research is being done!

Well, this is fun. I seem to have corralled a new "1" stalker - open.

If they can harness 2 electrons per photon then why wouldn't they be able to double the efficiency? An improved efficiency of 5% seems underrated for this development.

Because the kinetic energy of each electron is lower than in single photon systems. Basically that means that the voltage output of the solar cell will be somewhat lower, partially offsetting the increase in current and preventing the power from doubling.

I thought the same of 'lite' until I noticed they seemed to make all sides of various debates down no matter what; assertions or evidenced facts and reasons etc.

'open' seems to be like 'lite'; purposely running around marking virtually everyone 1. Occasionally they appear to randomly mark up a nonsense post. More a troll lurker than a stalker.

They should have taken the best currently available solar cell and use their pentacene power-doubler coating on that. Using a crappy organic solar cell made of fullerene and poly(3-hexylthiophene), their efficiency numbers are less than impressive.

And while these trolls keeps spitting FUD on anything that doesn't stink of oil, solar energy has reached, in some country, cost competitiveness with fossil fuels (see http://phys.org/n...a.html). I hope they are paid for this.

If they can harness 2 electrons per photon then why wouldn't they be able to double the efficiency?

The energy you can get per photon is detemined by the bandgap of your material. The bandgap is fixed, so the closer the photon's energy is to the bandgap the better (because any excess energy in the photon will just get lost).

Now here's the difficulty:
You can choose a material with a bandgap that is large which lets you catch high energy photons. The downside is that there are fewer high energy photons in sunlight than low energy photons.
Or you can choose a bandgap material with low bandgap and collet the infrared - but you'll lose all these juicy high energy photons.

What they are doing here is splitting the high energy photons into two low energy photons and then having two photons impact on a low bandgap material.

In effect you make better use of the full energy of all the photons and lowering the waste factor.

If they can harness 2 electrons per photon then why wouldn't they be able to double the efficiency? An improved efficiency of 5% seems underrated for this development.

Because you didn't read the article