Academician of CAS Mr. Yu Dapeng: the Possibility of Rapid Growth and Industrialization of Graphene2017-06-28 09:26:09 (GMT+8)
Andre Haim and Konstantin Novoselov, scientists at the University of Manchester, were awarded the 2010 Nobel prize for physics for graphene materials. There are tens of thousands of companies and graphene related all over the world, we can do is to pick the most simple to do, but none of the properties of graphene really play out, graphene is two-dimensional atomic material, and this material is too difficult.
Graphene material is very good one, physics is simple, the less complex the more perfect. The experiment proved to be a very desirable material, and some even said graphene could replace silicon. However, graphene is not a panacea, a congenitally deficient condition, such as semiconductor electronic devices require stable, open and close ratio is good, this is the fatal weakness of graphene.
How was graphene discovered? Is the tape to tear tear tape a pencil, pencil, tape and new tear tape used, such a split into two, two into four, continued, eventually get a whole piece of single atom crystal. So far we have no other way to prepare single crystals, and graphene single crystals have been a great challenge so far. In response to this problem, my team at Peking University made great progress in the growth of graphene single crystals.
On August 8th this year, we published an article in the field of professional publication "Nature" magazine. In the case of 1000 degrees, the crystals are obtained by dissociation of methane, which is characterized by a very small size and a high density, all like a regular six pointed star. My students are curious, he said with what is on the back side, take a microscope to see, found that very low density, the number is very small, but big, two growth rate is completely different, in a negative growth rate is 150 times the growth rate is more than two orders of magnitude. Prior to our work, all the growth records are summarized to obtain the essential reason for the growth rate of graphene. Now the competition is fierce, there is a large area of perfect graphene single crystal, can do a lot of things.
Companies have an advantage- they don’t have to publish articles. What really works for Japanese people is not published, and the real issue is to overcome the problem and let the world power to make it clear, or it's basically of little value. However, the domestic evaluation system requires us young people to publish articles and send articles in such high impact magazines as Nature and Science. This is something we are pushing forward.
Let us introduce to you, we test a layer of atomic graphene properties, things hard, not hard. Plastic is hard to break, this is a phenomenon in our life, good bad strain, with a bearing, bring good results, the strain can also strain silicon, faster strain can run, the processor is such a technique based on such a strained silicon device carrier run soon, is a good use of very good physical parameters, to choose many physical properties.
In general the copper material, shape variable is 0.5%, with the point force is broken, the nano this material becomes more and more strong, especially like graphene break break is very difficult, this is our team has been studying these, a research work strain on the physical properties of the material, do study on mechanical properties of graphene was based on this basis. A layer of atomic crystal, method of transfer point we just can carry the development, can make graphene moved to where it is needed, you can put two layer by physical method to measure the strength of a graphene layer, two layer, three layer research.
This is an example of this map to dig some holes, the graphene layer of graphene after moving over the hole after the break to see is not the same, can see through a microscope.
This is our entire process, and we process a series of voids by means of micro nanofabrication. Transfer over a layer. This is another area, covered with a layer of graphene, the hole is a hole that is 5 microns, we use atomic force microscopy, using AFM tip on how deep is the shape variable will know, push the words through the parameter, know this thing, what time to fracture. This is our use repeatedly with a needle pressing graphene, crushed the case. Each line is difficult, first to move a layer of crystal, and then transfer, and then measured, you can see each event, after a series of experiments to prove that this graphene in the strongest of modern materials. The young's modulus of our steel is 0.2 T PA, and our graphene exceeds 1 T PA.
Our team last year in graphene crystal growth this year has been a very important breakthrough, we can produce very graphene crystal, this is our chance to break all made, we do some research methods of physical development, physical properties, characteristics of the device, to find some new the phenomenon of effect, we developed a method of single crystal graphene operation is accurate and controllable, a layer of two layers with physical properties, including mechanical and optical properties, which we are engaged in physics research most look forward to, thank you.