Guest_Jim_* Posted May 4, 2015 Posted May 4, 2015 The future of many technologies may be flat, thanks to advances with two-dimensional materials like graphene, boron nitride (BN), and molybdenum disulfide (MoS2). The last of those three materials is of special interest to some as it is the only of the three to be a natural semiconductor, but its performance tends to be less than predicted. Researchers at Columbia University have been investigating this and found an explanation and solution for the discrepancy. In previous work, the researchers discovered that encapsulating graphene, a plane of carbon one atom thick, in boron nitride improved its electron mobility by a factor of 50. Electron mobility is a measure of how quickly electrons can move through a material, so better mobility means better performance. The reason the encapsulated graphene performed better is because the encapsulation reduced the disorder from exposure to the environment. By encapsulating MoS2 in BN, with graphene at the ends to act as contacts, the researchers found electron mobility increased by a factor of 2 at room temperature, bringing it closer to the theoretical limit. At low temperatures the increase was on the order of 5 to 50 times better, depending on how many layers there were. Further analysis at low temperatures revealed that contamination at the interfaces is still the main source of disorder, which means there is still room for improvement. With 2D semiconductors and other materials potentially able to push past the performance of modern technologies, you can bet this is going to be investigated more. Source: Columbia University Back to original news post Share this post Link to post Share on other sites More sharing options...
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