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Nanotechnology Boosts Solar Cell Performance

Zonk posted more than 6 years ago | from the two-great-tastes dept.

176

Roland Piquepaille writes "Physicists from the University of Illinois at Urbana-Champaign (UIUC) say they have improved the performance of solar cells by 60 percent. And they obtained this spectacular result by using a very simple trick. They've coated the solar cells with a film of 1-nanometer thick silicon fluorescing nanoparticles. The researchers also said that this process could be easily incorporated into the manufacturing process of solar cells with very little additional cost. Read more for additional references and a photo of a researcher holding a silicon solar cell coated with a film of silicon nanoparticles."

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176 comments

Oh no, it's Roland again! (3, Insightful)

Baddas (243852) | more than 6 years ago | (#20311621)

I wish I had access to the slashdot front page for my articles.

Try reading the article. (-1)

Anonymous Coward | more than 6 years ago | (#20311697)

I know Roland gets a lot of hatred here, but he actually provides us with some of the most interesting articles. Unlike the typical FUD we see so often, the submissions from him cover practical, real-world scientific discoveries. So instead of jumping on the hate train, read his article, and learning something about science.

Re:Try reading the article. (4, Interesting)

Baddas (243852) | more than 6 years ago | (#20311725)

It only bothers me because he linkjacks it with his blog.

If he was just posting an article, with a link to the EurekAlert post, it'd be all good. Instead, he has to post about his spammy blog, as well as his (paid?) blog on ZDnet.

The ratio of decent links to spam is 1:2 in this article.

Re:Try reading the article. (5, Informative)

Baddas (243852) | more than 6 years ago | (#20311757)

Also, he doesn't post the whole story (60% improvement in the UV spectrum) but rather the more sensational version (60% improvement!). That's pretty dishonest.

Re:Try reading the article. (1)

CraniumDesigns (1113153) | more than 6 years ago | (#20312311)

it's not dishonest. it's misleading, but not dishonest. it's like saying "4 out of 5 dentists recommend...". it could be 5 insane quack dentists. you don't t think that when you read/hear it, but it's still accurate.

Re:Try reading the article. (1, Insightful)

Anonymous Coward | more than 6 years ago | (#20313911)

> it's not dishonest. it's misleading, but not dishonest.

Honest people don't mislead others. Natch.

Re:Try reading the article. (1)

Frosty Piss (770223) | more than 6 years ago | (#20311839)

It only bothers me because he linkjacks it with his blog.

Hmmm... How many other blogs and sites featured at Slashdot also have ads? Nearly ALL of them?

Don't make it right. (1)

FatSean (18753) | more than 6 years ago | (#20311939)

n/t

Re:Try reading the article. (2, Insightful)

Baddas (243852) | more than 6 years ago | (#20311985)

Big difference between posting something original on a blog with ads, and paraphrasing an article on your own ad-filled blog solely for the revenue.

If I went around ripping off the AP, I'd get a nastygram from their lawyers. Why do we tolerate it more when it's a creepy-looking Frenchman?

Re:Try reading the article. (2, Insightful)

nuzak (959558) | more than 6 years ago | (#20312083)

Big difference between posting something original on a blog with ads, and paraphrasing an article on your own ad-filled blog solely for the revenue.

Doesn't that describe slashdot pretty well?

Re:Try reading the article. (1)

Baddas (243852) | more than 6 years ago | (#20312167)

Well, this is a community site, where I can spout off my opinions. So, yes, but with the addition of trolls, and editors, and other people and viewpoints.

Re:Try reading the article. (1)

shaitand (626655) | more than 6 years ago | (#20314231)

'Doesn't that describe slashdot pretty well?'

Yeah but the Slashdot editors don't submit the slashdot version of the articles to other sites.

Re:Try reading the article. (3, Funny)

geobeck (924637) | more than 6 years ago | (#20312979)

Why do we tolerate it more when it's a creepy-looking Frenchman?

I've asked that question after every Gerard Depardieu movie.

Re:Try reading the article. (1)

geobeck (924637) | more than 6 years ago | (#20313009)

Why do we tolerate it more when it's a creepy-looking Frenchman?

Because if we don't, he will fart in our general direction, you silly English kiniggit!

(Sorry, I couldn't resist the two-fer.)

Re:Try reading the article. (1)

Jafafa Hots (580169) | more than 6 years ago | (#20313573)

I went to his blog to see what all the fuss was about. Then I read your comment. When I was on his blog I didn't see a single ad, wondered why people don't like him. Also wondered why he bothers since it can't gain him anything because of no ads.

Now I realize it's because I'm running Firefox with adblock (and noscript). I'm so used to a net without ads I had pretty much forgotten their existence. Which leads me to wonder - why is a typical Slashdot reader (you're typical, right?) seeing ads? Why are you not running Firefox with adblock (and maybe noscript)?

The stuff people put up with willingly or out of conservativism (the little 'c' kind, the kind that makes you averse to change)... I just don't get it.

Re:Try reading the article. (1)

sumdumass (711423) | more than 6 years ago | (#20313623)

They are using the fairly superior Internet explorer 7.

It has all the wanted features of firefox and other popular browsers that have been making headway on Microsoft's browser lock in market.

Ehh. the real reason is marketing speak. Someone has tricked the drugstore geek.

Re:Try reading the article. (1)

blackicye (760472) | more than 6 years ago | (#20314037)

It only bothers me because he linkjacks it with his blog.

Hmmm... How many other blogs and sites featured at Slashdot also have ads? Nearly ALL of them?


Hmmm...How many other blogs and sites featured at Slashdot with ads is "featured" on a weekly basis with low signal to noise ratios? One, Piqy's blog.

Re:Try reading the article. (1)

danlock4 (1026420) | more than 6 years ago | (#20314139)

Hmmm... How many other blogs and sites featured at Slashdot also have ads? Nearly ALL of them?
It depends on how good your browser's ad-blocker is.

Re:Try reading the article. (0)

Anonymous Coward | more than 6 years ago | (#20311895)

The ratio of decent links to spam is 1:2 in this article.

More like 1:1

Re:Try reading the article. (1)

Baddas (243852) | more than 6 years ago | (#20311999)

His name link to primidi (his blog), plus his link to ZDnet (also his blog) in the article body, VS one link to the article in question.

Re:Try reading the article. (0)

Anonymous Coward | more than 6 years ago | (#20311913)

Dude, he provides valuable content. He distills complex scientific material into concise, pointed articles that average people can understand. My background is in accounting, not science. I'm still interested in the discoveries that are made. But I don't want to sit there and read pages and pages of scientific journals, most of which I won't understand.

But thanks to Roland, those discoveries become known to people like me. I appreciate the work that those scientists are doing, because Roland brought me word of their findings in a way that I can easily and quickly digest. That's true value, my friend. He's made me more productive and more knowledgeable by summarizing otherwise lengthy journal articles.

Re:Try reading the article. (0)

Anonymous Coward | more than 6 years ago | (#20312021)

Wow...you are very ignorant. OPEN YOUR EYES, MAN! Thanks to Roland, 2000 babies die every year of spamosis! Thanks to Roland, AIDS is ravaging parts of Africa. And thanks to Roland, kittens will die! Open your eyes... And stop the hate.

Re:Try reading the article. (4, Informative)

Baddas (243852) | more than 6 years ago | (#20312067)

Nice astroturf. He distills a half-page article into a half page blog post. Inaccurately.

Placing a film of silicon nanoparticles onto a silicon solar cell can boost power, reduce heat and prolong the cell's life, researchers now report.
"Integrating a high-quality film of silicon nanoparticles 1 nanometer in size directly onto silicon solar cells improves power performance by 60 percent in the ultraviolet range of the spectrum,"
Becomes

Physicists from the University of Illinois at Urbana-Champaign (UIUC) say they have improved the performance of solar cells by 60 percent. And they obtained this spectacular result by using a very simple trick. They've coated the solar cells with a film of 1-nanometer thick silicon fluorescing nanoparticles.

That's a whole 12 characters shorter, and leaves out the important words 'in the ultraviolet spectrum', which changes the meaning completely. Also, those emitted words are 27 characters long, so if they were properly included, his summary is actually more wordy than the original source.

It's almost word for word. And it's wrong.

Mod Parent Up (0)

Anonymous Coward | more than 6 years ago | (#20312209)

He brings up a very good point. +1 Informative!

So mark him down (1)

Colin Smith (2679) | more than 6 years ago | (#20312247)

In Firehose.

 

Re:Try reading the article. (0)

Anonymous Coward | more than 6 years ago | (#20312023)

I know Roland gets a lot of hatred here, but he actually provides us with some of the most interesting articles
So instead of jumping on the hate train, read his article...

Hey Roland - how's it going? Figured out another way to try to get people to read your blog?

Re:Oh no, it's Roland again! (0)

Anonymous Coward | more than 6 years ago | (#20313147)

Did *you* see this article before RP posted it? And if so, did *you* submit it? You can quibble about the way he does it, or how often he gets stuff posted or whatever, but the fact of the matter is that HE has pointed out an interesting bit of information that a lot of people here would like to read. YOU, on the other hand, have not. Go back home -- your village is missing its idiot.

Correction (5, Informative)

friedo (112163) | more than 6 years ago | (#20311623)

The nanoparticles improve efficiency by 60% in the ultraviolet spectrum. The visible light spectrum is only nominally affected.

It's still pretty cool, though.

Re:Correction (2, Interesting)

sl70 (9796) | more than 6 years ago | (#20311771)

Yeah, but the efficiency is so low to start with, anyway, that increasing it by 60% may not make much of a difference. Amorphous silicon cells have an efficiency of about 6%. Increase that by 60% and we get ... 9.6%! Nothing to write home about.

Re:Correction (4, Interesting)

Original Replica (908688) | more than 6 years ago | (#20312015)

9.6%! Nothing to write home about.

As gas prices creep ever higher and coal plants become less and less desirable a partial conversion to solar power starts to become a very possible reality. Adding just one kilowatt worth of solar power to each of America's 116 million homes would reduce the power consumption almost 1/3rd. http://www.frugalfun.com/solarfest.html [frugalfun.com] The system to get "off the grid" discussed my link costs a fair amount of money, and even a 1 KW system costs $10,000 right now, but if the solar panels can suddenly cost 60% less (by being more efficient) then the price of a 1 KW system could reasonably drop to $5000. Not a huge cost when you are talking about much of todays housing market. Five grand is less than the price difference between a Prius (22K) and a Ford Focus (15K). Solar might well become widespread after all, not because it is efficient, but because everything else is slowly rising to match solar power's high initial cost.

Re:Correction (1, Interesting)

IConrad01 (1105603) | more than 6 years ago | (#20312303)

A 60% increase in photovoltaic conversion efficiency -- assuming the process as a $0.00 cost, which it will not -- that would represent a roughly 37.5% reduction in cost. Given that this process is, as yet, not self-assembling, the cost is likely to be well into the thousands as-is -- precision alignment of forcibly assembled nanoparticles is expensive ; then you also have to consider the durability issues and the like; any medium of protection for the coating, in the interests of durability for anything resembling a reasonable life-span, will likely again further increase costs. All in all, this is not a solution. We're likely to get more out of the use of self-assembling chlorophyll-based photovoltaic polymers.

Re:Correction (1)

mdsolar (1045926) | more than 6 years ago | (#20312579)

Prices have come down a lot since 2002. Commercial installations a beating grid pricing and some financing mechanisms can get residential down to $0.07/kWh: http://mdsolar.blogspot.com/2007/08/tuppence-in-su n.html [blogspot.com] . This trend of lower prices should continue for a decade at least and will make solar cheaper than all other sources of power. Some business developments in storage may make the combination of solar plus storage as cheap as any other form of power as well: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com] . Nice SolarFest blog entry.
--
Rent solar power: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com]

Re:Correction (0)

Anonymous Coward | more than 6 years ago | (#20313417)

Using your numbers, the difference in price between a Focus (15K) and a Prius (22K) is 7K. 7K is larger than 5K, not less than. If you're offering to sell $7000 for $5000 can I be first in line?

Re:Correction (0)

Anonymous Coward | more than 6 years ago | (#20314035)

Learn to understand what you've read before attempting to correct it in the future.

Re:Correction (1)

mikael (484) | more than 6 years ago | (#20312569)

Another improvement to the efficiency of solar panels is to surround each cell with a little parabolic mirror. Apparently, this helps concentrate the sunlight onto the cell. Then there are methods of stacking two solar cells with different absorption characteristics on top of each other [sciencemag.org]

I would guess that the future goal is to have solar cells be able to absorb every possible frequency of sunlight.

Re:Correction (1)

misleb (129952) | more than 6 years ago | (#20312879)

It is worse than that because it isn't even 60% total increase in efficiency. Just 60% in the ultraviolet range.

That said, a percentage improvement is good because theoretically it could be applied to future solar cells which will presumably have a much better base efficiency.

-matthew

Re:Correction (4, Funny)

goldaryn (834427) | more than 6 years ago | (#20311843)

Still pretty useful though I bet.. but:

As the alcohol evaporated, a film of closely packed nanoparticles was left firmly fastened to the solar cell.

Whoa, whoa, whoa! Back up, bad idea!




(yeah I know it's only isopropyl alcohol. but still never something you want to hear!)

Re:Correction (3, Insightful)

phoenixwade (997892) | more than 6 years ago | (#20312119)

As the alcohol evaporated, a film of closely packed nanoparticles was left firmly fastened to the solar cell.
Whoa, whoa, whoa! Back up, bad idea!
Why? the only issue I could see would be dumping the alcohol into the environment, but since it's evaporating off - building a recovery system into the process would save money in manufacturing, and is a no-brainer. So I'd think it very unlikely that a regular dumping of alcohol into the environment would occur, for the best of reasons from a business point of view - it's cheaper to do it the right way.

Re:Correction (5, Funny)

Anonymous Coward | more than 6 years ago | (#20312711)

Hahahahahaha. Man, you totally missed his point.

He wasn't talking about the effect it might have on the environment. He was joking about "alcohol" as in booze being left out and undrunk long enough that it evaporated.

See, in a place like Ireland it's considered near criminal to waste ale or lager. So the thought of alcohol evaporating is a disturbing thought to most Irishmen and Irishwomen. It bothers them much like the thought of global warming bothers environmentalists.

Re:Correction (1)

confused one (671304) | more than 6 years ago | (#20313455)

One does not want to hear of alcohol being allowed to evaporate... One wants to drink the alcohol.

(Let us assume it is ethanol, for argument sake.)

Still something (5, Informative)

Moraelin (679338) | more than 6 years ago | (#20311941)

It's still something, because to knock an electron out, the minimum frequency of the photon has to be at least the difference between the conduction band (where you want that electron) and the lower-energy valence band (where the electron originally is.) So you have a minimum energy cut off point. Exactly where that is, depends on the material, but generally you won't get any power out of the infrared falling on that cell.

However, the downside is that photons with higher energy than that bandgap, well, the extra energy is essentially wasted.

So basically, say, if you used Germanium at 0.67 EV bandgap, you'd catch more photons than with Silicium at 1.11 EV bandgap, but get less useful energy (i.e., electricity as opposed to heat) out of each photon.

And the higher frequency the photon, the more you waste as heat. So you won't waste more in the visible spectrum (well, unless the photon had less energy than the bandgap, in which case it's completely wasted), but in the UV spectrum you waste a lot.

So reducing the waste in the UV spectrum is really where it counts the most. Sure, it would be neat to gain everywhere, but the UV range is where we waste the most.

Their talk about fluorescent particles, makes me think they're essentially converting an UV photon into at least one lower frequency photon. The question is what they do with the extra energy. At the simplest imaginable way, you'd get at least two low energy photons from one UV photon.

On the other hand, it seems to be a bit more than that, from that short summary linked to. From their claim that they improve voltage, not just current, and that something happens at the interface between the particles and the substrate, it sounds like essentially they created a bunch of new junctions there. I.e., that it's a new way to make a multi-junction solar cell.

Multi-junction cells aren't exactly new, but traditionally they've been very expensive so far. If these guys invented a cheap way to make one, kudos to them.

On yet another hand, it will be interesting to see on exactly what existing cells can their film be applied. On silicon or other semiconductors, ok, I can see how it would form an extra junction. Would it also work on, say, Dye-sensitized Solar Cells? There essentially their particles would come on top of the dye, and I'm not sure how well that works. It'll be interesting to find out, eventually.

Voltage (2, Interesting)

benhocking (724439) | more than 6 years ago | (#20312171)

So basically, say, if you used Germanium at 0.67 EV bandgap, you'd catch more photons than with Silicium at 1.11 EV bandgap, but get less useful energy (i.e., electricity as opposed to heat) out of each photon.
Can't you just increase the operating voltage to capture most of the extra energy? An electron moving across a larger voltage produces more energy. How large you can set the voltage depends on the energy in the electrons being knocked out — or am I missing something?

Silicon Nanoparticles (3, Informative)

GravitonMan (1145905) | more than 6 years ago | (#20312587)

At the end of the blog Roland asked why they didnt use multiple sizes of silicon nanoparticles, this was my long winded reply:

I am a graduate student working on the synthesis of silicon nanoparticles for solar cells and other applications. While silicon nanoparticles have been syntheszed for over 20 years, and their are many ways of synthesizing them, it is still very difficult to control the size of the particles. Unlike CdSe based quantum dots where the size of the particles is determined by how long your let the reaction run for, 1 min for blue 30 min for red, and various time lengths for other colors, silicon nanoparticles are more complex.

Silicon nanopariticles while they are still quantum dots, since the energy levels are somewhat quantized emit very differently as well. Silicon is an indirect band gap semiconductor, however the blue emitting silicon nanoparticles emit light with a direct band gap transisiton, where as they red emitting silicon nanoparticles are controlled by more surface effects and emit in a low energy indirect band gap transition which is slower and allows for more energy loss in other modes.

Anyways, what it comes down to, is it is difficult to make various sizes of silicon nanoparticles. I would also like to add that this technique is not very promissing for several reasons, they epense and other problems with traditional silicon etched solar cells still exist. Cost, lack of flexibility, low effeciency, heavy, glass... This method does not take full advantage of multiple exciton generation which was just proved for silicon nanoparticles in ACS journal of Nano Letters this week. PbSe quamtum dots have shown to generate 7 exciton for just one photon, which in theory could be converted to 7 electrons from 1 photon...someday. But 2.6 excitons from silicon nanoparticles is still pretty good. Especially when I have a way to get the excitons into free electrons And silicon is a non-toxic cheaper alternative to the PbSe quantum dots.

Re:Still something (1)

largesnike (762544) | more than 6 years ago | (#20312601)

On yet another hand...
far out man!, how may hands have you got?

Re:Still something (0)

Anonymous Coward | more than 6 years ago | (#20313681)

you'd catch more photons than with Silicium

Isn't that next to Dilithium in the periodic table?

I kid, I kid... [wikipedia.org]

Silicium? (3, Funny)

camperdave (969942) | more than 6 years ago | (#20314117)

Yes, you are too late to send your letter to the Prussian consulate via the 4:30 autogyro to Siam.

Re:Correction (2, Informative)

speculatrix (678524) | more than 6 years ago | (#20311943)

there's quite bit of UV in sunlight, so for photovoltaic panels which are to be used outdoors this is a real gain.

the cost of making PV panels is still too high compared to the energy you can harvest using them (I choose to use "harvest" specifically because they capture energy from the sun rather than generating from oil for example) over the expected lifetime of the panels. the other problem with PV panels is the environmental cost of manufacture + transport + ancillary electronics to make them useful and the cost of disposing/recycling. whether photovoltaics will reach the desired efficiency to make them economically and environmentally cost effective before biological (algae, bacteria etc which can "generate" methane or hydrogen for fuel) systems are perfected is an interesting question.

Correction-Capturing ancient plants. (1, Funny)

Anonymous Coward | more than 6 years ago | (#20312005)

"(I choose to use "harvest" specifically because they capture energy from the sun rather than generating from oil for example) over the expected lifetime of the panels."

And how do you think plants get their energy? By burning dinosaurs?

Re:Correction (4, Informative)

afidel (530433) | more than 6 years ago | (#20312475)

the cost of making PV panels is still too high compared to the energy you can harvest using them (I choose to use "harvest" specifically because they capture energy from the sun rather than generating from oil for example) over the expected lifetime of the panels.
I'm not sure if you're talking about energy cost or economic cost, but either way you are wrong. Solar panels make up their production energy cost in a fraction of their design life, and they are competitive with most non-renewables even at todays cost let alone the expected cost of those sources over the design life of the panels.

Re:Correction (5, Interesting)

hedwards (940851) | more than 6 years ago | (#20311949)

That's correct, but what you failed to note is that the UV spectrum contains a much larger amount of energy than either the visible or the infrared spectra do. Shorter wavelength, higher energy. And the higher energy particles are the ones that are the most desirable anyways.

Re:Correction (2, Informative)

m4cph1sto (1110711) | more than 6 years ago | (#20312441)

This is incorrect. UV radiation is of higher energy, but much lower intensity than light in the visible range, so overall much less energy is extracted from UV, and improving UV efficiency is not a big deal. The technological challenge in the development of photovoltaic materials is to develop a system that works efficiently in the visible range.

Re:Correction (0)

Anonymous Coward | more than 6 years ago | (#20312101)

That's because this is their business plan:

Step 1: Completely destroy protective ozone layer, vastly increasing the amount of incident UV radiation.

Step 2: ??????????

Step 3: Usher in new era of "eco-friendly" solar power, and PROFIT!

not cool (1)

epine (68316) | more than 6 years ago | (#20312913)

The whole stupid FA never once gives the percentage improvement when exposed to a sunlight spectrum. Not cool. Not cool at all. I'm sure it was an easy oversight. Sunlight is an obscure point of reference in this debate. After all, sunlight is nowhere near as common as water or air.

This 60% UV is just ONE of the configs... (5, Insightful)

Ungrounded Lightning (62228) | more than 6 years ago | (#20313707)

The nanoparticles improve efficiency by 60% in the ultraviolet spectrum. The visible light spectrum is only nominally affected.

It's still pretty cool, though.


This whole series of "only 60% of the UV part" threads is missing the rest of the article. That was just for ONE size of naonparticle, suitable for converting light to the middle of the visible range. They ran the tests for another size, suitable for converting to visible red, and got a higher conversion result, as expected.

Solar cells completely miss photons below the bandgap energy and only peel off the bandgap energy from those above it. They have a bandgap in the infrared so they get most photons, but only take that first 0.6 electron-volt chunk of their energy and lose the rest as heat. That's great if you have an infrared photon at 0.603 eV, not so hot for visible light photons at 1.8-3.1 eV, and pretty crummy for UV photons at 3.1 to 12 or so eV.

Films of nanoparticles have an interesting property: They absorb photons of various wavelengths and emit photons of particular wavelengths related to their size. But they don't do that in the solar-cell style of chopping the right-sized hunk off a more energetic photon and throwing the rest away. Instead they are able to combine energy from multiple lower-energy photons to generate one of the desired energy, chop several desired energy photons out of a high-energy one (and keep the leftover shavings to combine with others to make more desired-energy photons), and trade energy among their neighboring particles.

So it was expected that a film of nanoparticles on a solar cell would grab the energy from photons all over the spectrum, convert it to the energy characteristic of the nanoparticle size, and re-emit that. The improvement from efficiently salami-slicing and stacking photons should be better than losses from such things as emitting the photon in the wrong direction, giving a big boost to the cell.

And to some extent that was happening: Feed UV photons to nanoparticles that chunk 'em into something in the 3 eV range and you get more out of the UV hitting the cell than you would without the film - without appreciably affecting the output from the visible light. You're averaging about 1 2/3 IR photons worth of energy, instead of 1, for each incoming photon. Feed it to nanoparticles that chunk it up finer, down to 2 eV or so, and you get more out of your UV and also start improving on even visible light.

That's a good sign for doing what you really wanted to do: Use nanoparticles that emit just a tiny squidge above the solar-cell's bandgap, chunking all the photons into the right size for the cell and wasting very little of their energy. (But maybe still losing a bunch by emitting them in the wrong direction. That might be improved by putting the nanoparticles at the bottom of wells in the cell rather than on a flat surface.)

But the experiment produced a surprise: The VOLTAGE went up! WTF?

That means one of two things:
  a) The nanoparticles affected the bandgap.
  b) The nanoparticles coupled directly into the cell's "circuitry" in some non-obvious way.

b) might lead to something even better: Nanoparticles that capture the photons, chunk and stack them into some desired size (voltage), and deliver them directly to the wiring. That could get virtually ALL the incoming energy into your wires.

A solar cell with efficiencies in the .90s could be a whole heck of a lot better than even the experimenters were originally chasing. So it's no wonder they published now, with only two sizes of particles tested.

Hot DAMN!

Re:This 60% UV is just ONE of the configs... (1)

robbak (775424) | more than 6 years ago | (#20313973)

What I'd like to know: Why wasn't _that_ the original article? Assuming it is correct, it is orders of magnitude more informative than either articles! mod informative +10!!

now what to do (1)

ILuvRamen (1026668) | more than 6 years ago | (#20311645)

Is it FINALLY going to be efficient enough to add solar panel edging to the trim and room of hybrid cars so they constantly recharge the battery and you can run off it almost all the time? I could see 100+ MPG on a decent liter engine that way.

Re:now what to do (1, Funny)

Anonymous Coward | more than 6 years ago | (#20311783)

Only if you live on mercury.

Re:now what to do (2, Interesting)

ILuvRamen (1026668) | more than 6 years ago | (#20312543)

but wait, I drive a Mercury so that counts too lol. But seriously, look on ebay for 150-200 watt solar panels. They're not very large, only about five and a half by three and a half feet. I found a 200 watt one that exact size that claims 12.6% module conversion efficiency which I think isn't so good but let's say this one gets the added bonus from the nano-layer and gets up to like 300 watts. So with a transformer or whatever to get it down to 12 volts from 30-ish volts, that's 25 amps it's putting out in the best sunlight. And my battery charger can charge an entire average car battery in 2 hours at 6 amps and 12 volts. So parked outside of work for 8 hours with a solar panel the size of the roof, hood, and trunk of my car (i.e. 3x the one mentioned above), I could charge empty to full a hybrid car battery with such a large capacity that none like it even exist yet. It'd be somewhere in the neighborhood of like a 600 amp hour battery charged from empty to full, which is about 25x the capacity of a normal car battery I think

Re:now what to do (1)

Original Replica (908688) | more than 6 years ago | (#20313037)

How many gallons of gas would you have to save before a solar panel roof paid for itself? If the solar panel roof gives you even one extra MPG it would pay for itself in one hundred gallons. I think the real trick of making a solar panel roof work would be having your car know that it was OK to run the battery down on you way to work, so that it had somewhere to store the solar recharge. Maybe a switch/sensor connected to the clock and the current output of the solar panel would do the trick.

Re:now what to do (1)

ILuvRamen (1026668) | more than 6 years ago | (#20313079)

Well I never drove a hybrid but I assume if it has a full battery the gas engine idles and the electrical engine takes over completely. That might but be true but I dunno. If that's the case, my car gets approximately 90 MPG according to the realtime MPG chip while coasting off an onrap from 65 MPH to 0 which the engine idling. So if the solar panel cost $1000 which is about right, it'd pay for itself after buying $252 in gas or something like that.

Re:now what to do (1)

BUL2294 (1081735) | more than 6 years ago | (#20312063)

No way... Look at the moveable LED construction signs on the sides of the road--those have solar panels the size of a car roof (and a battery pack the size of a fat kid's ass). You think the power draw from an 8x3 character LED screen comes anywhere close to giving the power needed to assist a gasoline engine in a car???

Honestly, I'd be shocked if cars could increase their gas mileage by 5% with solar cells on the roof & an electric motor assisting the gasoline engine using today's technologies...

Re:now what to do (1)

PieSquared (867490) | more than 6 years ago | (#20312839)

While running it doesn't do much... but how much power does your car use while it sits in the parking lot outside your office building for 8 hours a day? I could see you getting enough power to go a few miles without gas, maybe double your MPG on the way home.

So you aren't going to get a solar cell powered car any time soon, but it might be decent for a commute at this point. As long as you can get past the startup cost, of course.

no need for individual tin hats anymore? (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#20311647)

as yOUR georgewellian uncle is providing a one size fits all 'solution'.

what a surprise/secret?

previous post:
corepirate nazis now providing 'cloud' cover
(Score:-1, Troll)
by Anonymous Coward on Tuesday August 21, @09:48AM (#20303795)
http://portland.indymedia.org/en/2002/06/13240.sht [indymedia.org] [indymedia.org] [indymedia.org] ml [indymedia.org]

we're watching right now as they spray phoney clouds over our city. yikes almighty. took some pictures of the 'trail', & the 'lovely' 'rainbow' around the sun.

it must not be that good for US or the whoreabull corepirate nazi execrable would be bragging about it.

see you there?

Re:no need for individual tin hats anymore? (0)

Anonymous Coward | more than 6 years ago | (#20311669)

you had me at "hello"

Title misleading (1)

heli_flyer (614850) | more than 6 years ago | (#20311703)

The article says efficiency was boosted by 60% IN THE ULTRAVIOLET REGION. Not overall efficiency.

Re:Title misleading (1)

omgamibig (977963) | more than 6 years ago | (#20312231)

So, we just need to get rid of the ozone layer. Then we are essg entially in the clear.

Re:Title misleading (1)

vranash (594439) | more than 6 years ago | (#20312695)

As sarcastic as I'm sure this post was meant to be, I was thinking essentially the same thing: At this point in time, isn't UV the *MOST* useful band to be increasing solar cell capacity in? Besides the ozone depletion, you supposedly get more UV bouncing around on an overcast day due to smog and cloudcover anyhow, and if it's bad for your skin, then it must be plenty good for your solar cell's 'bad day' electricity production.

I'll be watching intently for more information on this technology. Given the low wattage computing devices we have coming out now, while it might not be enough to run a car or house off of, I can fully see it covering my cell phone charging, and perhaps even 'perpetual' low-wattage laptop/pda usage during the day, just by wearing a silly hat or backpack array of these panels, even in overcast conditions providing enough outdoor capacity to keep my devices running without looking for an outlet to plug into.

Where are the numbers? (1)

loshwomp (468955) | more than 6 years ago | (#20311751)

Summary:

We've just invented a new-and-improved [solar cell|battery|ultracapacitor] and it's really really great but we're not going to quote any actual absolute metrics.

We have units for expressing solar cell performance, but I didn't see any in TFA.

TiO2, UV, and Solar Cubes (4, Interesting)

purduephotog (218304) | more than 6 years ago | (#20311759)

While at Purdue one of my friends worked on a process to increase solar cell efficiency by etching TiO2 coatings into long, thin whiskers that helped 'whisk' photons down into the surface of the material. It basically doubled the efficiency of a 3% cell in the visible range. Solar hasn't taken off.

Glass typically blocks UV. Most glazings contain glass. If this only boosts (and 60%, while a large number, is still a tiny increment in efficiency) the UV efficiency then there may be limited use... unless you count concentrator applications.

The "Sun Cube" (http://www.treehugger.com/files/2007/04/sun_cube_ by_gre_1.php [treehugger.com] uses lenses to concentrate light onto small, very efficient space-grade solar panels. Each panel (if memory serves) was on the order of 1 sqcm, allowing these very expensive but very efficient (25%+) panels to be used. The overall effect was to to take 1 m2 down to 10 sqcm of chips.. and yet have the power output be about the same. Combine that concentrator technology with higher utilization of UV bands AND ultra-efficient space grade panels and you've got a winner (concentrators work ONLY in direct sun- no clouds).

Just some food for thought.

Re:TiO2, UV, and Solar Cubes (2, Insightful)

DerekLyons (302214) | more than 6 years ago | (#20312213)

[on concentrators]

The overall effect was to to take 1 m2 down to 10 sqcm of chips.. and yet have the power output be about the same.

Which matters how if it still takes up 1 m2 of roof space?
 
Concentrator systems leave me cold because of this. They concentrate (pardon the pun) on increasing the output per cm2 of solar cell - when the real need is to increase the output per m2 of roof space occupied. (The difference is subtle, but important.)

Re:TiO2, UV, and Solar Cubes (1)

Xonstantine (947614) | more than 6 years ago | (#20312717)

Which matters how if it still takes up 1 m2 of roof space?
Because solar cells are expensive and concentrators are cheap. The problem with solar cells is primary cost, not space.

Re:TiO2, UV, and Solar Cubes (1)

purduephotog (218304) | more than 6 years ago | (#20313135)

Which matters how if it still takes up 1 m2 of roof space?

Good point. You can't increase insolation. Go higher or use mirrors, but you're stuck with that 1kw to 1.5kw /m2. BUT say you use a concentrator that only utilizes 10sqcm of capture material. You've invested in the land, the mirrors to drive them, the mechanisms... and suddenly they increase solar performance to 50%. You want to upgrade? Replace 10sqcm of material. Everyone else has to replace 1m2 of material.

Seeing as the high efficiency solar cell material was going for about 10$/sqcm... were you to have one full meter of it you'd be looking at a very pretty penny. Smaller upgrade costs for a given fixed infrastructure cost.

Just more food for thought.

(And yes, I completely agree- but there's no easy way of making a 100km tunnel of vacuum ;-P )

Re:TiO2, UV, and Solar Cubes (1)

complete loony (663508) | more than 6 years ago | (#20313965)

If it costs less energy to produce the smaller cells, then you might have something worth using. There's no point going solar if it takes more energy to produce the cell than is captured over its lifetime.

Man he's right (1)

codefungus (463647) | more than 6 years ago | (#20311795)

That is a researcher holding a silicon solar cell coated with a film of silicon nanoparticles.

Another breakthrough.. (0)

Anonymous Coward | more than 6 years ago | (#20311821)

..that none of us probably won't see available. This is like, what, the tenth solar power technology breakthrough this year alone? And still none of it is available to anyone, private person as company alike, as breakthrough after breakthrough just keeps disappearing in thin air a while after the news has gone public.

Re:Another breakthrough.. (3, Insightful)

timpaton (748607) | more than 6 years ago | (#20312243)

Oh FFS, what is it with /.ers and their "Why can't I buy it at Walmart yet?" comments?

Have you people never heard of research?

A lot of these stories are of lab demonstrations, or even just theoretical breakthroughs that MAY, one day, be developed to the point that they become useful. Or they may inspire further research that may lead to further research that may eventually be commercialised in a completely different form to how they were first demonstrated.

If you want to read about new ideas and developments that are unlikely to impact your life for several years, you're in the right place. If you want to read about new products that you can buy right now at your local mega-mall, try the junk mail they stuff in your mail box.

Re:Another breakthrough.. (0)

Anonymous Coward | more than 6 years ago | (#20312771)

The mistake you are doing in your ranting here is that you too consider only what's mentioned here; the breakthroughs shelled out in the news the past 7-8 _months_. There have been breakthroughs in this area reported the past 8-10 _years_ that still have not surfaced in usable shape; some haven't even been mentioned a second time in context of ongoing research.

If you claim the /.'ers to be narrow and blunt in their comments, atleast you could try to be otherwise by reading up some.

Re:Another breakthrough.. (2, Informative)

mdsolar (1045926) | more than 6 years ago | (#20313015)

The AC has a point though that slashdot does not do a lot of followup. For example this 2005 article: http://science.slashdot.org/article.pl?sid=05/02/2 8/1224245 [slashdot.org] has not really had a follow up to say that they have products on the market now: http://www.nanosolar.com/products.htm [nanosolar.com] , or that this 2004 article: http://science.slashdot.org/article.pl?sid=04/10/2 2/1534212 [slashdot.org] about solar shingles is also seeing application in new housing now. Looking back, there are articles on ideas that have not panned out so far, especially in organic solar technology. But, that does not mean that they won't.
--
Get solar power: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com]

Re:Another breakthrough.. (0)

Anonymous Coward | more than 6 years ago | (#20314033)

Another nanotech solar technology taking off!

http://www.dyesol.com/ [dyesol.com]

Dyesol's technology is based on Dye Solar Cell (DSC), which has been identified in the Japanese and EU Photovoltaic Roadmaps as the emerging solar technology, it has also been called the most promising advance in solar cell technology since the invention of the silicon cell.

DSC technology can best be described as 'artificial photosynthesis' using an electrolyte, a layer of titania (a pigment used in white paints and tooth paste) and ruthenium dye sandwiched between glass. Light striking the dye excites electrons which are absorbed by the titania to become an electric current many times stronger than that found in natural photosynthesis in plants.

Compared to conventional silicon based photovoltaic technology, Dyesol's technology has lower cost and embodied energy in manufacture, it produces electricity more efficiently even in low light conditions and can be directly incorporated into buildings by replacing conventional glass panels rather than taking up roof or extra land area.

Advantages include not necessitating the use of high-priced raw materials, a manufacturing process that does not produce toxic emissions, and the potential for rapid efficiency enhancement.

Dyesol enjoys a lead position in developing and commercialising DSC technology.

60% more than ~0 is hardly very much (3, Interesting)

Chalex (71702) | more than 6 years ago | (#20311837)

So I RTFA, and here's the bit: "improves power performance by 60 percent in the ultraviolet range of the spectrum" and "in conventional solar cells, ultraviolet light is either filtered out or absorbed by the silicon and converted into potentially damaging heat, not electricity."

So a conventional solar cell gets ~0 energy from this part of the spectrum, but if you coat it with this special coating, it gets 60% more! And how much is that exactly?

Now if you use a different coating (2.85nm), then it improves performance "in the visible part of the spectrum" by 10%. How much energy does a conventional solar cell get from just the visible part of the spectrum? Unspecified!

Cost (2, Insightful)

grassy_knoll (412409) | more than 6 years ago | (#20312001)

The process of coating solar cells with silicon nanoparticles could be easily incorporated into the manufacturing process with little additional cost, Nayfeh said.


How about something to make solar cheaper to purchase, so that the initial investment can be recouped before the expected replacement date?

Re:Cost (1)

TheRaven64 (641858) | more than 6 years ago | (#20312203)

Making cells more efficient does make panels cheaper, since you need fewer cells for the same power output. Or, if you are trying to cover a fixed area, it means that you have more surplus power to sell back to the grid to help cover the cost.

Re:Cost (1)

grassy_knoll (412409) | more than 6 years ago | (#20312383)

I take your point; what I'm trying to get at is the inital outlay for solar isn't recouped over the life of the installation.

For example[1]: if you need one $15,000 super duper efficient unit, or 10 $1,500 electric shack bargain bin units, if the savings over the life of the unit is $10,000 the inital outlay is too expensive. This doesn't cover maintenance costs over the life of the unit(s), which would decrease the savings.

[1] costs illustrative only.

You're simply.. wrong. (0)

Anonymous Coward | more than 6 years ago | (#20312603)

The cost of solar panels today is completely recouped in areas where electricity is expensive.

Here in Southern California, panels pay for themselves in about ten years, but will last at least 25 years with 85% efficiency. Guaranteed.

Even if you figure the life as 30 years, and factor out the state rebate, the panels are still generating twice as much "money" as they cost. If you're one of the poor saps in the fourth or fifth "tier" over-baseline, you can recoup the cost of a small residential PV in five to eight years!

And if you think electricity won't get more expensive over the next 25 years, well...

Re:Cost (1)

dbIII (701233) | more than 6 years ago | (#20312779)

These are photovoltaics - the things we have on satellites, navigation bouys and other places where nobody goes. Where do you get the idea that maintainance is a significant cost?

Re:Cost (1)

dbIII (701233) | more than 6 years ago | (#20312751)

Back in the 1960s photovoltaics were a very expensive proposition but wide scale semiconductor fabrication changed all that. The parent poster and moderators should consider more recent information.

Re:Cost (1)

ErikZ (55491) | more than 6 years ago | (#20313225)

Why don't you just post more recent information instead of telling the OP that they're ignorant?

Seems best suited for non-terrestrial uses (4, Insightful)

Shadowlore (10860) | more than 6 years ago | (#20312043)

First, we need to be careful here. A 60% improvement in the conversion among UV spectrum does not necessarily equate to a 60% increase in a given PV cell. If the particular cell is more of an infrared or visible light spectrum oriented cell, you'll see a minor, if any, improvement. So before anyone starts grabbing random solar cell outputs and starts applying a 60% increase in power and get modded "insightful" for bad information, let's get that part out there.;)

With the main advantage being in the UV spectrum, it seems to me the best application would be to UV preferential cells in orbit or on Mars, Luna, etc.. Doubly so given the difficulty in shedding excess heat in Space.

Amazing. (1)

The Living Fractal (162153) | more than 6 years ago | (#20312077)

How many of these new cells would it take to power this [theonion.com] I wonder? With that 60% increase of the 0% we were getting previously from the UV band, I would imagine quite a few bananas will get eaten before those monkeys actually collide!

Please Rationally Consider My Very Valid Opinion (0)

Anonymous Coward | more than 6 years ago | (#20312105)

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100% efficiency ... what would it bring? (1)

Dillenger69 (84599) | more than 6 years ago | (#20312131)

so ...

Would a 100% efficient solar cell be black, non reflective, and cold to the touch in full sunlight?

If all the light went in the front and the only energy leaving were through wires in the back it would have to be, wouldn't it?

Re:100% efficiency ... what would it bring? (1)

imikem (767509) | more than 6 years ago | (#20313363)

In this house, we obey the laws of thermodynamics!

UV light (1)

Kaenneth (82978) | more than 6 years ago | (#20312169)

much UV light penetrates cloud cover directly, so this enhancement may be a good boost for solar power on cloudy days, when it may be needed more.

Refreshing (1)

mosb1000 (710161) | more than 6 years ago | (#20312177)

It's good to finally see an article about solar cell efficiency improvements where an actual prototype has been built and tested.

The best part? (0)

Anonymous Coward | more than 6 years ago | (#20312329)

It's only five years away?

Watch... (0, Troll)

SilverBlade2k (1005695) | more than 6 years ago | (#20312411)

Cue the Exxon-Mobil lobbyists and lawyers to try to make this illegal, or to purchase the patent outright...

Yes! (3, Funny)

Hanging By A Thread (906564) | more than 6 years ago | (#20312609)

So now I can use my calculator with my black light......groovy!

Satellite Use? (2, Interesting)

Yehooti (816574) | more than 6 years ago | (#20312747)

If we could shed about 60% of the solar panels on our space vehicles, that would be a tremendous boost in our ability to launch neat stuff cheaper. The question that comes up though is, how well will this new coating survive the rigors of the space environment? If it degrades faster than our current choice then we probably cannot qualify it as a replacement for our current cells. Until that question is addressed, flown and tested, this remains as only a neat future potential. Space drives the race.

Re:Satellite Use? (1)

WillRobinson (159226) | more than 6 years ago | (#20314073)

In reading this, (I support a customer who does sat cells) it would look like you might get between 3 and 10 percent possibly. But space level cells are gallium arsenide based and not silicon. Since I do not work in the front end i will not guess.
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