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Ultra-Thin Solar Cells Can Be Bent Around A Pencil (computerworld.com.au)
angry tapir quotes a report from Computerworld: Scientists in South Korea have developed solar cells thin enough they can be bent around a pencil. The cells could help usher in the use of solar energy in small portable gadgets where space is at a premium. The cells are fabricated onto a flexible substrate that is just a micrometer thick -- one-half to one-quarter the thickness of other "thin" solar cells and hundreds of times thinner than conventional cells. [The team at the Gwangju Institute of Science and Technology in South Korea managed to reduce the thickness by directly attaching the cells to the substrate without the use of an adhesive. They were stamped onto the substrate and then cold welded, a process that binds two materials together through pressure, not heat. The scientists tested the cells and discovered they can almost be folded in half -- wrapped around a radius as small as 1.4 millimeters. A paper describing the work was published on Monday in Applied Physics Letters, a journal of the American Institute of Physics.]
Students pencils will generate electricity all around the world!
These would go great on electric cars. They wouldn't be enough to charge the batteries for putting the car in motion, but they would be enough to power sensors, displays, entertainment systems.
And cars stay out in the sun a whole lot of time.
It cannot work: it is dark inside there.
Reading comprehension? 100 micrometers is just 1/10 millimeter.
Know the truth, there is no pencil.
~.~
I'm a peripheral visionary.
This is huge news for those of us that suffer from arthritis. No more struggling with those ridiculously thin pencils! Freedom at last!
Garry Knight
. . . like cost and durability ? If they are thin and flexible but degrade or fail easily (or are temperature sensitive, or the substrate breaks down under prolonged UV exposure, for example. . .) then it's only a nifty tech demonstrator.
Likewise, if the cost per watt is an order of magnitude higher than other, less-flexible technologies.
It's a complicated balancing act, and articles like this simply don't give much more information than a press release. Neat Tech ? Sure. Usable Tech ? Insufficient information. . .
TFA has several links but the link that the paper supposes to be located is not working
The link to the paper - http://www.scitation.aip.org/content/aip/journal/apl/108/25/10.1063/1.4954039 - drops me to the main page - http://scitation.aip.org/
Can anyone tell me the conversion rate of this ultra think solar cell?
Thanks !
Problem: It's dark inside
Solution: OLED
The whole point of bendability is not that people are going to start wearing solar cells on their clothing (though we could see "charging hats" for hikers), but that it becomes practical to stick cells directly onto objects that flex slightly in use, like shingles. Solar shingles could make rooftop PV a default standard for new construction.
The cells could help usher in the use of solar energy in small portable gadgets where space is at a premium
Now maybe we can finally get some sweet portable calculators
I will start to unleash my solar powered pencil empire immediately!
The trouble is that the solar cells only have a single direction of flexibility; as such, they cannot be applied to compound surfaces. I would like to see panels that can be applied to an aerodynamic surface, like that of a velomobile.
Still more important though, is to focus on weight, efficiency, and cost. To get about 300W I still need close to 6 square feet of panel. Further, even a lightweight panel system weighs over ten pounds.
Yes, an electric assist touring bicycle is avery special purpose; but, it is an example of achievable solar transportation. Further, as it is is my project, it is a application that interests me (I expect to be cross country ready by next summer).
Having it wrapped around a pencil certainly seems like a poor way to use a solar cell.
Why is this news? Commercially available flexible solar has been around for more than 20 years - check out PowerFilm . This may reduce the minimum bend radius by a few millimeters but nothing major. The problem historically with photovoltaics that are not mounted under glass is degradation due to water ingress and failure of the interconnects due to repeated flexing. I would love to see what testing they have done on this material. Maybe they are for space based use where water ingress is not an issue?
From the article, these are composed of thousands of GaAS micro-cells. Each cell is about 15% efficent. However, they appear to be spaced far enough apart to cover only about 1/4 of the area. That makes the array 3.75% efficent at best. Maybe future work can move them closer together.
And it's patented.
I've held them in my hand, at the UW CEI conference on campus.
-- Tigger warning: This post may contain tiggers! --
What about a pen or marker?
"They were stamped onto the substrate and then cold welded, a process that binds two materials together through pressure, not heat."
So, heat is a localized-effect of the pressure which eventually binds the two materials.
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