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Researchers at Tohoku University have developed an innovative method for fabricating semitransparent and flexible solar cells with atomically thin 2-D materials. The new technology improves power conversion efficiency of up to 0.7 percent, the highest value for solar cells made from transparent 2-D sheet materials.
Transparent or semi-transparent solar cells with excellent mechanical flexibility have attracted much attention as next-generation smart solar cells. They can be used on the surfaces of windows, front display panels of personal computers and cellphones, and human skin. But issues remain with regard to improving their power conversion efficiency, optical transparency, flexibility, stability and scalability.
Led by Associate Professor T. Kato, the team showed easy and scalable fabrication of semi-transparent and flexible solar cells using transition metal dichalcogenides (TMDs), an atomically thin 2-D material. Using a Schottky-type configuration, power conversion efficiency can be increased up to 0.7 percent, which is the highest value reported with few-layered TMDs. Clear power generation was also observed for a device fabricated on a large transparent and flexible substrate.
0.7 percent solar power conversion efficiency isn't much.
Toshiki Akama et al, Schottky solar cell using few-layered transition metal dichalcogenides toward large-scale fabrication of semitransparent and flexible power generator, Scientific Reports (2017). DOI: 10.1038/s41598-017-12287-6
(Score: 1, Insightful) by Anonymous Coward on Tuesday September 26 2017, @08:15PM (13 children)
How much fossil fuel must be combusted, generating large volumes of greenhouse gases, to generate the electricity needed to power the manufacturing of these solar cells?
How many centuries of uninterrupted use are required before they've offset the greenhouse gas emissions produced during their manufacturing?
(Score: 0, Troll) by Anonymous Coward on Tuesday September 26 2017, @08:26PM (9 children)
IKR? Why even bother, we should all just do the planet a favor and kill ourselves now. You first . . .
(Score: 1, Insightful) by Anonymous Coward on Tuesday September 26 2017, @08:32PM (4 children)
Those are important questions to ask about any technology. If the goal of such technology is to reduce the impact on the environment, the whole picture must be considered. It does us no good to replace "polluting" technologies with "green" technologies that actually have a much larger carbon footprint than the "polluting" technologies when we factor in the manufacturing and operating costs of the "green" technologies.
(Score: 2, Insightful) by Anonymous Coward on Tuesday September 26 2017, @09:04PM (3 children)
Sort of... moving to solar / electric would make it feasible to power all human activity by the Sun. No more carbon footprint aside from the actual materials. Mining / processing / manufacturing could all be done with solar.
That is why you get flak for asking the question. Yes carbon footprint as a whole is important, but it is NOT a reason to prevent switching over since after the switch we will no longer need to consider the burning of gas/oil/coal as part of the process.
(Score: 3, Informative) by bob_super on Tuesday September 26 2017, @11:03PM (2 children)
If every unit you produce uses more carbon than it will replace, then you're better off not switching.
(Score: 0) by Anonymous Coward on Wednesday September 27 2017, @06:17AM (1 child)
If you don't switch, you'll use all that carbon anyway.
(Score: 2) by urza9814 on Thursday September 28 2017, @03:02AM
If the device isn't sufficiently efficient you won't be able to switch (using that device alone) at all, and you'll just waste extra carbon producing a dead-end.
(Score: 0) by Anonymous Coward on Tuesday September 26 2017, @08:42PM (1 child)
Please don't joke about suicide, and please don't recommend it, even when being sarcastic. Suicide is a very serious issue that should not be taken lightly. Joking about it is also very disrespectful to the memory of Aaron Swartz [wikipedia.org], the Internet's Own Boy.
(Score: 0) by Anonymous Coward on Tuesday September 26 2017, @09:09PM
Even sarcastic internet comments can be the metaphorical straw that broke the sad person's heart.
(Score: 0) by Anonymous Coward on Tuesday September 26 2017, @08:53PM (1 child)
OR we could try looking at actually sustainable methods for producing energy, such as biofuels.
(Score: 2, Insightful) by Anonymous Coward on Tuesday September 26 2017, @08:57PM
Or even modern nuclear technologies. If anyone is holding back the development of much cleaner and safer energy sources, it's the "environmentalists" who fight such research tooth and nail.
(Score: 2) by tfried on Tuesday September 26 2017, @08:33PM (1 child)
TFA won't tell us how much energy is needed for the production of these cells. But considering the actual cells are few atoms thick, I do not think the energy requirements would be over the top in large scale production. (In essence the process seems to be chemical vapor deposition on an auxiliary foil, then transfer to target surface; perhaps not trivial, but not inherently energy intensive).
Now the 0.7% efficiency is the thing that doesn't sound too great, but on the upside it comes at 90% transparency. So wherever you have tinted windows, today, a layer or three of these might be used instead. Only a niche application, but still a niche.
(Score: 2) by bob_super on Tuesday September 26 2017, @11:11PM
> Only a niche application, but still a niche.
To put actual numbers on it: 0.7% means that in peak sun at low latitudes, the power from your perfectly angled window (a windshield, most likely) could, ideally charge one or two USB devices (no, not USB3, the old 5V/1A ones).
Unless you put those on your sunroom/conservatory/greenhouse ceiling, I don't see how anyone will get an ROI for even the time spent thinking about putting them on.
Vertical windows, even on skyscrapers? Might pay for the copper in the power cables by the time the wrecking ball comes around.
(Score: 3, Insightful) by c0lo on Tuesday September 26 2017, @10:35PM
My guess? A fraction of the energy cost of the glass substrate the window pane is made of.
TFA "Device fabrication on the large size PEN substrate"
The energy intensive step is the CVD (chemical vapour deposition). Given that the film is 3 atom layers in thickness, one need to vaporize a very small amount of reactants at temperatures comparable with the glass melting temperature (Tungsten diselenide melts at 1200C)
In contrast, to make that sheet of glass that is your window requires to melt the entire mass of it to pass through the rollers.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford