High-Performance Flexible Organic Transistors

Roland Piquepaille writes "Organic — or carbon-based — transistors are not new and can be used to design flexible computer displays, RFID tags and sensors. However, these organic single crystals could not be mass-produced because they needed to be individually handpicked. But now, researchers at Stanford University and the University of California-Los Angeles (UCLA) have developed a new method for building flexible organic transistor arrays. Even if the researchers have reached a density of 13 million crystals per square inch (or 2 million per square centimeter), there are still several issues to solve before this method can be used for commercial applications of these fast transistors."

Has Roland reformed?

[RobertB-DC]

I had to look twice, but sure enough, there are no links to Roland's ZDNet blog in this submission! No "But click here for more information", nothing but a single link to a source document. I don't think anyone can begrudge him the link in his name.

So perhaps Roland has reformed, or perhaps the Slashdot editors just got tired of our whining and broke out the scissors.

But I'm still going to tag the article as "pigpile", just because it's fun.

Re:

[Ant P.]

Maybe the people operating the bot caught on that people had noticed the "read more" repetition, and changed its output.

Re:

[Janek Kozicki]

aye aye sir! tagging pigpile, done.

A well written summary!!!

[RingDev]

Defining key terms, expressing measurements in standard and metric, appropriate link to the article. Well done!

-Rick

Actual achievement

[MITEgghead]

The actual achievement here is significantly different then the summary suggests. This paper published in Nature describes a way that single-crystal organic transistors were patterned with a "stamping" technique onto flexible substrates. It is all three things that make it notable (and worthy of being in Nature): single-crystal organic, stamping, flexible substrates. Single-crystal organics have significantly higher mobilities and thus faster switching speeds and less power. Single-crystal growth is difficult because it previously required hand-placing a crystal seed or selecting crystals that grew on the correct axis. Stamping is a technique that enables easy manufacture onto flexible substrates because typically the flexible substrates (plastics) can't take the heat used in generating the transistors. So the transistors are grown on another more durable substrate and then transfered onto the flexible substrate. They also showed that the single-crystal organics were flexible enough not to break under torsion. Typically, crystals are more brittle like crystaline silicon and that is why they're not suitable for use in the next generation of flexible screens that will enable vastly reduced footprint for high-res, full-color, luminescent displays that will allow much bigger, roll-away screens for mobile applications.

This brings forth a question...

[Khyber]

So with a crystal of a pure material (etc. diamond for carbon,) why can't we just semi-flex/torque it (sideways rotation along a vertical axis,) and it not act like a sponge? Is it the crystalline structure beign so inflexible regardless of it's multiple points, or is it because of the coherence of the bond on the outside of the entire matter that makes it so inflexible?

I'm just a noob to geology, so I'm throwing out questions. Don't mod me down, just give me informative answers with backup, alright?

real single crystal?

[kenodi]

It was about time that something like this shows up. However, I am a bit suspicious.

Do they show that indeed we are talking about single crystal system, and not single crystals randomly oriented (on microscopic level)? If is the latter, then we are talking about thin films: an array of single crystals differently oriented and lots of grain boundaries in between.

Well, the results are nice but isn't a bit early to pretend you are changing the world? With thin films this was done before. Again I suspect that what they have is more closely related to thin films rather than single crystals.

If they can show that all of their crystals have the same orientation, then they are on the safe side. But I think they are not on the safe side:

Several further advances will be necessary before the team's progress translates into commercial technologies. Among them is controlling how the crystals line up across the electrodes when the crystals form. Another key step will be ensuring better electrical contact between crystals and electrodes.

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[account_deleted]

Comment removed based on user account deletion

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[Joebert]

Whoever modded that offtopic can mark my words too, my dirty laundry is the key to biomechanical technology I tell you !

I for one...

[locokamil]

... demand that all measurements in such articles be given in more standard units. When will people start thinking of those of us measure the sizes of our apartments in Square Libraries of Congress?

Kidding aside, this is an informative article... possibly the first such that I have seen on Slashdot since I joined.

Say what?!?!?!

[Khyber]

You must be new here. ;)

That many researchers?

[somersault]

"Even if the researchers have reached a density of 13 million crystals per square inch (or 2 million per square centimeter), there are still several issues to solve before this method can be used for commercial applications of these fast transistors."

That many researchers and still several issues to solve? Crikey.