Guest_Jim_* Posted March 25, 2015 Posted March 25, 2015 Quantum dots are an interesting technology that could one day find various uses in our devices and be used in solar cells. Before that can happen though, we must find efficient ways to produce them with various properties. Researchers at Rice University have apparently achieved that for graphene oxide dots made from coal. Quantum dots are semiconducting nanocrystals sometimes called artificial atoms or molecules. This is because they can have some of their properties very precisely tuned, including their optical and semiconducting properties. While large materials will react only with certain frequencies of light, depending on their electronic structure, quantum dots can have that structure tuned to work with any desired frequency. Producing them is so hard though that a kilogram would cost about $1 million. What the Rice researchers have found though brings that down to $100 a ton with two, single-step methods. One of them relies on ultrafiltration to sort the dots by size, a method already used for water filtration, and the other controls the temperature the oxidation process reducing the coal to dots occurs at. The temperature directly influences the size of the dots, which in turn controls the frequencies the dots interact with. The graphene quantum dots the researchers were working with are photoluminescent, so they emit one color light when light shines on them, and those made from anthracite produced colors from green to orange-red. To produce blue light, the researchers found it easiest to work with bituminous coal. Besides their optical properties and applications, quantum dots could see use in chemical reactions, thanks to their reactive edges. Source: Rice University Share this post Link to post Share on other sites More sharing options...
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