New Printable Solar Cells

[JavaMoose]

Here is a little snippet from the article:

"TORONTO -- Researchers at the University of Toronto have invented an infrared-sensitive material that's five times more efficient at turning the sun's power into electrical energy than current methods.

The discovery could lead to shirts and sweaters capable of recharging our cellphones and other wireless devices, said Ted Sargent, professor of electrical and computer engineering at the university.

Sargent and other researchers combined specially-designed minute particles called quantum dots, three to four nanometres across, with a polymer to make a plastic that can detect energy in the infrared."

I wonder how long this will take to filter down to retail.  Can you imagine just being able to unroll a roll of this and tack it down onto your roof?

[JavaMoose]

Oh, I forgot the one killer part of this:

"The film can convert up to 30 per cent of the sun's power into usable, electrical energy. Today's best plastic solar cells capture only about six per cent."

[Big All]

http://www.eurekalert.org/pub_releases/2005-01/uot-nnp010705.php

[wooferhound]

I read this article and it sounds interesting, a solar cell that can be painted onto a wall or made into threads and made into cloths.

But how do you attach the wires to it, which part is the positive side ?

[Jessum Dumguy]

The discovery could lead to shirts and sweaters capable

of recharging our cellphones and other wireless devices, said Ted Sargent,

professor of electrical and computer engineering at the university.

  Heres my off the cuff question to this,

Your wearing a shirt and pants outfit of this

stuff taking a walk on a nice sunny day.

Passing a puddle along side the road from

yesterdays rain storm a car whizzes by and SPLASH.

Does it short out making it a very uncomfortable

walk home to change?

BTW: That 30% was an estimate of future improvements and

in combination with existing visual light plastic

solor cell Techs not in addition.

Quote: Professor Peter Peumans of Stanford University,

Our calculations show that, with further improvements in efficiency, combining infrared and visible photovoltaics could allow up to 30 per cent of the sun's radiant energy to be harnessed, compared to six per cent in today's best plastic solar cells."

.

[cdg378]

sounds like a forward thinking patent to me, I wish I had it...

[Ungrounded Lightning Rod]

Existing multilayer amorphous panels have a stack of several (three, I think) layers, electrically in series, going from progressively shorter to longer wavelengths as the light penetrates into the cell.

The voltage across each layer is that of the bandgap.  The material is transparent to longer wavelength (redder, lower energy photon) light, but absorbs light at the wavelength of the bandgap and shorter (bluer, higher energy photons).  The excess energy of the photon, beyond that matching the bandgap energy, is lost, as heat or re-radiated near-infrared photons.

So if you stack it up blue-to-red-to-infrared the photons penetrate to the layer that can most efficiently use them.

You have to match your choice of bandgaps to the spectrum of the incident light, so you absorb about the same number of photons in each layer.  The current will be limited by the layer that absorbs the lowest photon count.

These guys were already talking about carefully creating nanostructures of several (three wasn't it?) particular sizes - no doubt to pull this stunt with several bands of infrared.  Perhaps they can continue with still smaller particles to get into the visible wavelengths.  Or perhaps not - in which case they can just cover their structures with the current generation stuff.

[Ungrounded Lightning Rod]

Also:  Perhaps these new structures work more like antennas than bandgap electron-hole pair devices, picking energy off the photons corresponding to their size and ignoring those too far off their resonance.  In that case you might be able to just mix them in a soup, if you still connect them properly to the power pickoff.

Or maybe you wouldn't need to wire them up in the right order.  Resonant structures can combine several photons of identical or very close frequencise to jump a carrier across a larger bandgap than a single photon can cover.  If the big one combined, say, six photons, the middle-sized one five, and the little one four, to push a charge carrier across a junction's bandgap, they might come out to about the same voltage.  Then you could use the same rectifier junction on all three, and use molecular "wires" with chemically coded ends to connect all the positive sides to the positive collector and the negative sides to the negative ditto, hooking them all in parallel.  This would be handy, turning infrared photons into juice at a more reasonable cell voltage up in the half-volt range or higher.

[wooferhound]

Here are all the comments that the readers of http://slashdot.org had to say.

http://science.slashdot.org/article.pl?sid=05/01/10/1832253&tid=126&tid=14

[BrianK]

yep that is kind of what I was thinking get wet and start felling a nice tingling or even OUCH. but hey it would be funny i would try it.

 .

[pyrocasto]

Hey, just wear some solar wet suits in the ocean. That way if you get bit by a shark he will let go very quickly. And you can turn the tables on jelly fish.