Not Transparent Aluminum, But Conductive Plastic

michaelmalak writes "Scientists at the US Department of Energy's Brookhaven National Laboratory and Los Alamos National Laboratory have fabricated transparent, thin films capable of absorbing light and generating electric charge over a relatively large area. The material, described in the journal Chemistry of Materials (subscription required), could be used to develop transparent solar panels or even windows that absorb solar energy to generate electricity. The material consists of a semiconducting polymer doped with carbon-rich fullerenes."

Comments

Application: Skyscrapers

[suso]

Sounds like this would be great for skyscapers, where you have huge windows all the way up and direct sunlight for long periods of the day.

Re:Application: Skyscrapers

[Bigjeff5]

These would be great in windows, but I don't see why it should be limited to windows, since it's a coating that could be applied to all sorts of things.

A covering for housing siding, for example, or attached to roofing sheets. Something like this, if it ends up being cheap (and it should, it's a super simple process to make - the trick was getting the chemical solution right), would have a lot more applications than just in windows.

Cross your fingers, I say.

Coming soon

[pooh666]

to a manufacturer in China..

Re:Coming soon

[Pinky's Brain]

Don't worry, the US patent owners will earn a lot more profit on it than the Chinese (they don't give a damn about patents, but if they want to sell it in the US they need the license nonetheless).

Re:Coming soon

[the gnat]

I work for the DOE (at a different lab), and from what I've seen, patented technology is almost always licensed to American companies. If it wasn't, a major argument for the existence of the national labs goes out the window, and Congress would probably throw a fit. I don't know if patent licenses come with strings attached (like "thou shalt not offshore manufacturing"), but my guess is that any company wanting to profit from publicly-funded basic research has to tread carefully.

(Obvious disclaimer: I speak for no one except myself - I'm just a lowly programmer anyway.)

tinted glass?

[HungryHobo]

I assume they'd act like tinted windows since they'd be absorbing some of the light.

car windows which gradually charge the battery perhaps?

Re:tinted glass?

[FatdogHaiku]

Why stop with the windows? Auto bodies normally have a "clear coat" over the pigmented layer, so why not have the entire vehicle surface act as a collector?

Re:tinted glass?

[Anonymous Coward]

Also if the battery is topped off on trickle charge, would it still make enough juice to run the vent blower? Would be nice to have a car that runs the fan and brings in fresh outside air while parked during those hot summer days.

Apocalypse averted

[Zerth]

Now when we run out of indium-tin oxide(or the chinese just stop selling it to us), we can still make LCDs, OLEDs, and EL wire.

The invisible man would be blind

[RevWaldo]

The more transparent it is, the less energy it can absorb. What level of efficiency can it achieve?

.

Re:The invisible man would be blind

[Raleel]

the question is, transparent to what, really. If it's opaque to everything _except_ human-visible light, that's still a pile of the spectrum and of energy.

Re:The invisible man would be blind

[Bigjeff5]

It's transparent because the film has a hexagonal structure - extremely thin (and therefore transparent) at the center of the hexagon, thick (and therefore opaque) at the edges of the hexagons. The electricity is generated at the edges, as that is where the light is absorbed and that's where all the electrons are ready to be knocked off their molecules. It's not blocking certain wavelengths and allowing others through (well obviously to some degree it is, but not in the visible spectrum). It's blocking light in certain parts and allowing light through in others.

It's basically going to tint the windows, how much will be determined by how densely the hexagons are packed - more hexagons means more electricity but also a darker tint.

Re:The invisible man would be blind

[jo_ham]

It really depends what part of the spectrum it is absorbing in. If it absorbs strongly in the near IR region but completely passes visible, then how transparent it looks to us really isn't going to affect how efficient it is. Some chemical bonds just don't absorb energy in the visible region, which is hopefully what they are going for here, so that the primary function of the window itself is not compromised.

Ideally you want to absorb the energy above the visible region - it's more energetic after all, but there's a huge range of the spectrum available to choose from, with only a small portion of it apparent to us as humans (at least through detection by our eyes - you can obviously perceive IR radiation directly and UV/Xrays/other ionising radiation indirectly with no instruments).

Re:The invisible man would be blind

[JustinOpinion]

It's transparent because the film has a hexagonal structure - extremely thin (and therefore transparent) at the center of the hexagon, thick (and therefore opaque) at the edges of the hexagons.

Actually it's a little bit more interesting than that. In addition to being thinner at the center, the light-absorbing polymer is not well-ordered (amorphous) in the center region, which leads to it being worse at absorbing light. At the edges of the hexagons, the polymer orders better, which allows it to absorb light more efficiently. This makes the structure more intelligent, in principle: if the honeycomb structure acts as one half of the conduction pathway (necessary for a photo-voltaic), then it makes sense to have the material close to it do the light-absorbing, and have the material further away (center of hexagons) which cannot participate in light harvesting, just be transparent. So this in principle allows one to design more efficient semi-transparent solar cells.

Peeling back the layers of hype a bit, however, these kinds of solar cells are horribly inefficient. The best materials we currently have to make plastic solar-cells ("organic photo-voltaics") have pretty poor efficiency. Making a solar cell that's semi-transparent just makes the efficiency (per unit area) even worse. But, this is fairly fundamental research: by demonstrating that they can tune the light-absorbing capabilities of the polymer based on its ordering (and control ordering by using the honeycomb patterning and preparation parameters), this provides useful information about how to make higher-performance plastic solar-cells. So this research may actually end up being more important for conventional solar cells ('opaque') than it is for window-coating solar-cells or whatever.

P.S.: The materials used in the paper have an absorption maximum at 503 nm (green), so they probably create a purplish tint. The absorption spectrum can be tuned to change the tint, however this will impact the solar collection efficiency.

Disclaimer: Some of the co-authors are colleagues of mine. However I wasn't involved in this work in any way.

Re:The invisible man would be blind

[JustinOpinion]

your efficiency per square foot may be crap, but your square footage can be huge. That's assuming, of course, this stuff ends up being cheap. The manufacturing process should be ultra cheap, but I don't know about producing the solution. It should be a lot cheaper than traditional panels, but will it be cheap enough to make it worth it? That's the question.

That's exactly right. The promise of organic photo-voltaics is that they will be so much cheaper to produce that the lower efficiency won't matter. But one of the harsh realities is that a photo-voltaic setup has certain fixed base costs (think of how much it costs to physically install each 1 m^2 panel, and tie it into a house's electricity system). Thus, according to industry partners, there is actually an efficiently level below which a solar material is not worth using even if it were completely free to produce. So, for organic solar cells to become commercially viable, they need to improve efficiency, even while reducing costs. Of course we're now reaching levels where it is indeed viable to use organic photo-voltaics, see for example Konarka's flexible solar panel that is built into a bag, so that it charges your cellphone; but there is a threshold of efficiency necessary to offset fixed installation costs.

Re:The invisible man would be blind

[Low Ranked Craig]

but there is a threshold of efficiency necessary to offset fixed installation costs.

This threshold will become lower as the costs of fossil fuel goes up. Assume for the sake of argument that the cost basis of solar tech like this doesn't change, the rising costs and shrinking supply of traditional sources will make things like this more attractive. Of course, it is likely that the costs for this tech will decrease over time...

Re:The invisible man would be blind

[Black Gold Alchemist]

It's only part of the solar panel. I'm over-simplifying, but solar panels are a sandwich of three layers: the transparent conductor (currently indium doped tin oxide), the semiconductor layer (silicon), and the back collector (metal). This discovery will replace that pesky transparent conductor layer.

Great idea

[RogueWarrior65]

This is the kind of implementation that actually makes sense. You don't need dedicated hardware or real estate to set it up. Granted northern exposure probably would work but put this stuff all over southern exposure windows in a whole city and tie it all onto the grid. It's akin to not using food crops for biofuels. Algae and switch grass make more sense.

Now the big key is getting the cost per kilowatt down where it's competitive with traditional power generation. And of course you really need a large scale storage system. I remember a Popular Science article about giant underground flywheels.

Re:Great idea

[belthize]

Not if you do it right, we just need to set them up so they properly affect the earths rotation, say give us 4 more hours of sunlight a day for more solar power. Two rocs with one stone.

More materials science overclaiming

[Animats]

Again, we have some minor bit of progress in materials science being touted as a big breakthrough. They haven't fabricated anything but a hexagonal membrane, which has been done before. They're not even able to make a small prototype device. From that, it's a huge jump to "Imagine a house with windows made of this kind of material, which, combined with a solar roof, would cut its electricity costs significantly. This is pretty exciting.". There are lots of other solar cell technologies which are much further along and still don't yield useful products. Nanosolar, a hype-based solar panel company, comes to mind. The enthusiasm for thin-film solar has decreased since ordinary solar cells became cheaper, and thin-film cells got stuck at half the efficiency of regular ones. This is turning into a manufacturing problem, not a technology one. "We grow every year with double revenue and almost double capacity. At end of the year, we will have 1.8 gigawatts of capacity and will have grown from 4,000 employees at the beginning of this year to more than 11,000." - Fang Pen, JA Solar, Shanghai.

Conductive plastic isn't a big deal. Conductive plastics are commercially available. The foam in which ICs are packed is conductive.

This is Los Alamos and Brookhaven, the old atomic labs, struggling to avoid more downsizing.

Getting around the paywall?

[znerk]

Some links that have more information, without having to give money to the Chemistry of Materials:

http://news.discovery.com/tech/material-could-collect-sunlight-from-roof-and-windows.html

http://www.lanl.gov/news/releases/scientists_produce_transparent_light-harvesting_material.html

Oh, and one more thing:
Buckminster Fuller strikes again! AHAHAHAHAHAhahahahahaha... hah.

--
I want my Dymaxion

The real action in solar

[Animats]

What's really going on in solar is that big US companies with real manufacturing expertise are moving in.

• Dow Chemical is about to release solar shingles. "About to release" means "passed UL certification last week" and "volume shipments in 2011". Solar enthusiasts have blithered about solar shingles for a decade, but Dow actually solved all the real world problems, like the roof not leaking, the interconnect system being safe, and the installation being do-able by a typical roofer.
• General Eletric is now active in solar. They make not only panels, but major parts you need to really get things done, like megawatt-sized inverters.
• 3M now makes solar panels.

This is where the action is. Solar is a heavy-manufacturing business, and it's the companies with experience in running big factories that are now taking over.

Re:The real action in solar

[belthize]

You can't have a manufacturing business until you figure out the technical details. There's a reason Dow invests 1.2B a year in R&D. Ten years from now I suspect there'll be an article on some new conductive something or other and somebody will point out what a waste that is because you can already buy windows for Andersen Windows that act as transparent solar panels.

Last year there were numerous scoffing posts at the announcement that Dow would be rolling out shingles next year.
http://hardware.slashdot.org/story/09/10/05/2126210/Dow-Chemical-Rolling-Our-Solar-Shingles-Next-Year?from=rss

Places like LANL aren't set up to invent and patent products (though they have), they do pure research and post their findings so companies like Dow, GE and 3M can further advance the findings as real products. It is extremely risky to do pure research, there is little or no guarantee that areas of inquiry will lead to anything let alone a cost effective product. A centralized system for pure research backed by the combined economic force of an entire nation and then distributed to focused companies to implement promising lines is about as efficient as it gets (efficient there is a relative term, it doesn' t mean it is in itself efficient, just more efficient than alternatives).

Lastly all conductive polymers aren't created equal, simply making a conductive plastic is not a one size fits all regime. Some of the best work in polymeric photovoltaics is being done at LANL which, oddly enough, is the point of the article.

Re:Windows?

[Anonymous Coward]

Your an idiot.....

Sew our ewe.....

if its transparent how does it absorb?

[goombah99]

How can a transparent thing absorb a large fraction of the energy? This sounds like an oxymoron.

Re:if its transparent how does it absorb?

[Anonymous Coward]

Humans are only able to "see" a very small portion of the spectrum of light. This leaves a lot of IR and some UV available for absorption without humans noticing.
Wikipedia has a nice chart of the spectrum here

Re:if its transparent how does it absorb?

[spike hay]

The great majority of the sun's energy that reaches the surface is in visible. That's why we see in visible rather than NIR or ultraviolet, which have pretty much the same optical properties.

The sun is pretty close to being a 5800K blackbody, which means that it emits primarily in visible, but also some UV and near infrared.

  However, the UV mostly gets cut off in the stratosphere by ozone (which is why the stratosphere is actually warmer that the upper troposphere). A good portion of the NIR is cut off by water and other stuff.

Some better article headlines

[noidentity]

Here are some improved article headlines:

Not Transparent Steel, But Conductive Plastic

Not Non-Conductive Plastic, But Conductive Plastic

Not Green Eggs And Ham, But Conductive Plastic

Re:What's the difference?

[znerk]

Not much, obviously. But, then again, what's the difference between a pile of dirt and rocks and a nuclear reactor?

Engineering :)

Well, that and the fact that one of them generates gobs of power, while the other just kinda sits there.

Re:Time to market

[Anonymous Coward]

That may be true, but I know for a fact that a lot of entrenched industry on the old money energy side hates the idea of solar and has gone way out of their way to make it not happen, because it threatens their business model. Solar can break the perpetual check to them, because eventually it can be paid off. You can NEVER pay off your local utility monopoly, and that's the way they like it. And speaking of hybrids, read up on large NiMH batteries and chevron, an oil company and how they bought up the patents, etc and then sat on it, refused to license it, making manufacturers start from scratch an building large ones, helping delay electric vehicles. Toyota had to develop their own, when it already existed!

Any way, back to solar. I've been into it for decades now, and back in the old days we had to do "guerrilla solar" (and also wind chargers, which are sorta hard to hide) because damn if you could get a "permit" to install it. Local electric company guys would get to the building inspectors (read:bribes) and no matter what, they wouldn't "permit" it, so we had to do it stealthily. This was on purpose, conspiracy, market manipulation stuff. You can google "guerrilla solar" for some stories about how much of a rip it was. Home Power mag has a lot of it in their old back issues.

I have NO doubt it still goes on with amazing solar breakthroughs, the patents get bought, then poofed away, stuff like that.

we already have transparent aluminum

[OrangeTide]

My watch is made with Transparent Aluminum.

Government waste.

[bigtrike]

Why are our tax dollars funding things like this when we're losing a war and faith based initiatives are underfunded? We need to shrink our government and trust that if there were any hope for this to work, private industry would be investing in it so they could maximize their long term profits.