Behind the Scenes At a Quantum Dot Factory 37
Tekla Perry writes: In a nondescript office complex in Milpitas, Calif., Nanosys is making enough quantum dots to populate 6 million 60-inch television screens annually. "The process goes on in what looks like a microbrewery. In about half a dozen large metal tanks ... Nanosys combines cadmium and selenium and adjusts the temperature, concentration, and catalysts added to force these precursors to combine into stable crystals of cadmium selenide. Then, by readjusting the conditions, the system stops the formation of crystals and triggers the beginning of crystal growth. A computer controls the process according to a programmed “recipe;” staff members monitor the growth of the crystals by shining light on them and measuring the wavelength of the fluorescence; the smallest crystals don’t fluoresce at all, then, as the crystals get larger, the wavelength changes. Nanosys stops the process when the fluoresced light hits the target wavelength, which varies depending on what particular display industry standard that the batch of film is designed to meet."
Quantum Dot? (Score:3)
Re: (Score:3)
Re:Quantum Dot? (Score:5, Funny)
Toxic chemicals in 'office complex'? (Score:1)
Both cadmium and selenium are toxic. Cadmium has been considered as an environment pollutant
I simply can't imagine someone setting up a factory which uses cadmium and selenium in an area described as a 'nondescript office complex'
How do they get the green light from EPA in the first place?
Re: (Score:2)
"How do they get the green light from EPA in the first place?"
By shining blue light on green quantum dots, I guess.
Bert
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According to TFA, they are nanoscale semiconductor crystals that turn blue light into narrow-spectrum greens and reds.
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I believe the use of 'quantum' is to sound high-tech and futuristic. Except of course to anyone who knows even the rudiments of quantum theory.
Re: (Score:2)
TFA discusses this, and they are working on cadmium-free dots, but they are harder to produce. They use indium and phosphorus for those.
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TFA discusses this, and they are working on cadmium-free dots, but they are harder to produce. They use indium and phosphorus for those.
Yes. The article also continues to further explain that the cadmium-free dots are less efficient, which makes them less-desirable to the display manufacturers.
Also, to GP, the CEO of the profiled company notes in the article that they do not release any Cadmium in the production of the quantum dots, but they have no control over how the displays are disposed of when they are no longer wanted. Considering the environmental consciousness that they are stated to show, I'm sure the company would love to get t
Re:Disposal problem? (Score:5, Funny)
that's racist. please use "native americium" going forward.
Republic of India (Score:2)
I can think of roughly 1.25 billion people who don't find "Indian" racist.
Re: Disposal problem? (Score:2)
It's pretty stable in salt form---much less of a problem than elemental Cd from batteries or Hg from florescent lights. Also, it's pretty well encapsulated in the TVs.
Thank you, Tekla Perry! (Score:4, Interesting)
I have been reading /. for far longer than my ID # indicates. IIRC, it was 1999 when I happened upon the site, I just didn't bother to join, because I never had anything useful to say. Back then it was "News for Nerds, Stuff that Matters." Unfortunately, that guiding mantra no longer adorns the /. bannerhead and we are poorer for it.
This submission is a perfect example of "News for Nerds, Stuff that Matters." The summary doesn't tell you everything, you have to click through and read the article to get the true value of it. I read the article and it was very informative. I learned interesting information from it. It wasn't just interesting, I might actually use that information in the future.
Thank you for perking up my day with interesting information and giving me hope that /. will continue to be a site to return to for quality information and news.
BE part of the SOLUTION. (Score:4, Informative)
Unless you're implying the editurs are idiots and ignore perfectly nerdulent story suggestions.
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Unless you're implying the editurs are idiots
No need to imply anything. That's already long-established fact.
Re: (Score:2)
The button to Submit [slashdot.org] a story is right in front of your nose a the top of the page.
Unless you're implying the editurs are idiots and ignore perfectly nerdulent story suggestions.
You are correct, sir, in that I have not done my part in keeping /. as it was, can, and should be. I implied nothing about the current editorial staff, nor did I wish to do so, regardless of my views on such matters in private. I would like to live up to my own perceived responsibilities as a member of the /. community. Based on my past history, however, that is unlikely to happen. I will, however, keep the thought of making such contributions closer to the fore, thanks to your comment. I can only hope
Re: (Score:3)
There is no red envelope or similiar notifications button, to see replies at a glance
Click the word "Slashdot" at the top left of each page to go to the home page, and your replies should be just below your username in a box at the top of the right column.
No way to even find old comments that slip off the relatively short comment list
I get a "Load More Comments" button at the bottom.
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How big is it? (Score:2)
Anyone know what the maximum size of a quantum dot is?
Could they make ones that emit microwaves, or even radio?
Re:How big is it? (Score:4, Informative)
Re: How big is it? (Score:3)
Short answer is no. Although there are plenty of other semiconductor devices that can operate in the microwave.
The "quantum" part of quantum dots is that the effective bandgap of the semiconductor, which controls the wavelength of luminescence, is increased by quantum confinement. Google particle in a box for more information.