Materials Science " magazine

Add artificial edge that allows atomic layer of molybdenum disulfide neat growthTechnology Daily News According to physicist organizational networks reported recently, Rice University and Oak Ridge National Laboratory (ORNL) developed in collaboration with scientists a new method that can control the molybdenum disulfide (MDS) consistently neat atomic layer growth , to manufacture two-dimensional electronic device toward a step forward .  Research published this week in the "natural . Materials Science " magazine.
Molybdenum disulfide is a semiconductor manufacturing functional components are required for two-dimensional electron in one of the three materials , they are expected to be made ​​invisible devices based components. In the latest study , the scientists hope to figure out a large and high-quality atom thick sheet of Molybdenum plate disulfide Can the chemical vapor deposition (CVD) furnaces grow and what features they have .  They want molybdenum disulfide with no band gap of graphene and hexagonal boron nitride insulator (hBN) binding, thereby making appearances effect transistor logic integrated circuits, photodetectors and flexible optoelectronic devices.
Last year, Rice University mechanical engineering and materials science professor Lou jun ( transliteration ) and Plymouth Kerr ? Ajayan said they successfully produced graphene and hexagonal boron nitride formed complex staggered structure, but in order to use they manufacture of advanced electronic equipment, also need a third material - molybdenum disulfide .  However, they said: "The will of molybdenum disulfide and carbon atoms together, we want graphene and molybdenum disulfide ( with hexagonal boron nitride ) combine to create a novel two-dimensional semiconductor parts , but because of their different structures , growth environment is different, so there are a lot of difficulties . They have not found a good way to grow molybdenum disulfide, many try to get the material structure is also inconsistent with the chemical vapor deposition method create molybdenum disulfide particles too small to have useful electrical properties.  But in the new approach, they noted molybdenum disulfide "islands" formed in the furnace is easy , blemishes and even dirt block will appear in the base of the furnace .  Rice University graduate Niina ? Naye Mei said: " with hexagonal boron nitride or graphene is different, molybdenum disulfide difficult nucleation .  However, we found that by toward the base adding any artificial edges nucleation process that can be controlled , and, in between these structures , molybdenum disulfide grow better . new method be grown particles about 100 microns , the nanoscale inside , enough for us to deal with them .
Oak Ridge National Laboratory 's team used aberration-corrected scanning transmission electron microscopy to the atomic structure of this new material imaging in order to clearly see individual atoms and changing the electrical properties of the material defects . The laboratory Juan - Carlos ? Eddie Robb said: " In order to improve the properties of two-dimensional material , first understand how they are put together is very important . Oak Ridge National Laboratory Microscope equipment so that we can see the material for the first time a single atom .  "
Rice University researchers estimate that these substances together so there are many ways , not only can be used in the form of two-dimensional layer can also be used in the form of three-dimensional stack .  Lou Jun said: "' natural crystal ' by the same ingredients together via van der Waals force , and now we can use different ingredients to create a three-dimensional crystal .  These different materials have different electrical properties and band gap, the kind of material placed on top of another so that we can obtain a new material - we called van der Waals solids .stacking order we expected to use any of its put together , this may be a field of materials science , a new approach .