Graphene "agitate" LED industry, rare earth elements to the edge of the station?

Reminiscent of the 2014, when China's A stock market still lingers at the end of the 7 year old bear market, the graphene concept shares soared with a collective adverse trend, and the new material has become a hot topic of discussion in the twinkling of a twinkling in the twinkling of a twinkling. As a new material that is 200 times stronger than steel and toughness, graphene has only one atomic thickness, and it has many excellent properties, such as good elasticity, strong conductivity, high transmittance and so on. It is understood that graphene is originally in nature, but it is difficult to peel off the monolayer structure. One layer of graphene is a layer of graphite, with a thickness of 1 millimeters of graphite containing about 3 million layers of graphene. For example, a pencil is gently crossed on paper, leaving a trace of a few layers of graphene, or even a few layers of graphene. The data showed that in 2004, University of Manchester physicist Andre Geim and Konstantin Novoselov successfully separated graphene from graphite, proving that it could exist alone, and that the two people won the 2010 Nobel prize for physics. However, only 10 years have been found by scientists, and the preparation technology and industrial application of the global graphene are in the initial stage. Graphene is known as the "king of new materials" as the "king of new materials", which is known as "black gold" because it is the thinnest, maximum strength, and the strongest conductive and thermal conductivity of nanomaterials. Even some scientists predict that graphene will "completely change the twenty-first Century", so it is likely to set off a new and disruptive new technology industry revolution that is sweeping the world. It is so many "halo", "bulls flicker" new materials, now get another new stage of research results, really gratifying. Little editor today will talk about the future of the application of this industry in our LED industry, which is also a promising new material, "graphene". Instead of rare-earth elements? In recent years, researchers at home and abroad have made great progress with the development of graphene. First, researchers from National Tsinghua University in China, who published an article in ACSNano, claimed to have used materials other than rare earth elements to produce white - light LED products. According to the introduction, the LED is based on the alkali metal strontium and built the metal organic frame (MOF), which combines the graphene and other materials on the MOF, forming a LED that can directly emit white light. The MOF mentioned here is formed by the combination of metal ions and organic materials. In the past 20 years, it has been widely used as a chemical separator, drug delivery, gas storage, catalysis and other fields. However, because of the general porosity and poor conductivity of MOF, it has been difficult to see this material in the field of optoelectronic. In fact, in the early research process, the white light MOF was basically combined with different kinds of rare earth elements. In order to solve the above problems, the researchers have to use the elements with good electrical conductivity, and at the same time, this element can also be stimulated to launch the light of the frequency band. So the researchers tried to replace the organic ligands, using the alkaline earth metal strontium to prepare the MOF material. They indicate that the addition of transparent electrodes graphene on the MOF surface improves the carrier mobility and does not affect the optical properties in particular. Because of the excellent thermal conductivity of graphene, the new white light diode has better thermal conductivity. On the periphery of the MOF material, the researchers also combined graphene, silica, and Zinc Oxide to allow it to be electrically driven. The use of MOF materials to make light emitting devices has undoubtedly given people a new idea. The test results also show that as a light-emitting device, the light is very close to the natural light. As a semiconductor device, its stability is better. During the two months of the test, there is little performance decline. On the other hand, this material is more environmentally friendly. Now that the rare earth elements are less and less, the new LED does not use rare elements, greatly reducing the use of the use of resources, and indeed can play a role in saving resources. In addition, the reduction of rare earth elements can also be effectively controlled for the environmental pollution caused by it. And because the light from the new material is very close to the natural light, there will be no strong blue light. The efficiency of the luminescence is greatly improved because of the absence of the shade of other colors. The consumption of electricity is reduced, and the emissions of greenhouse gases will also be reduced. "Zero defect" of graphene at the moment, many enterprises in the world are producing "graphene". Because they belong to two dimensional materials, there are few high quality graphene that can produce "zero defects". Although the prospects for the development of graphene are very promising, from the past to the present, global researchers have been looking for low cost methods to produce defective graphene. The good news is that German chemists have recently announced a way to produce cheap graphite - free graphene. Information refers to the current manufacturing technology of graphene, the size, area and defects of the product (influence of conductivity) and other aspects are still to be improved, so the semiconductor industry has not yet really used graphene. Finally, in the near future, a FAU research team, led by Professor AndreasHirsch, has made a breakthrough in reducing the flaws in graphene. According to foreign media, chemists at the University of Langen Nuremberg (FAU) in El, Germany, have now taken the lead in making graphite - free graphene with graphite. The results of the study were recently published in the nature communications. Traditionally, the conventional methods of making graphene are commonly used in chemical stripping of graphite. In this method, the metal ions are first nested in graphite (made up of carbon) to form intercalation compounds, and then separate the monolayer carbon atoms, namely graphene, by solvent, and then separate the stabilized graphene from the solvent. The problem is that in this process, due to the hydration or oxidation of the carbon atoms in the lattice, the final graphene may be defective. This time, FAU researchers used the additive, benzonitrile, and found a method of making graphene without defects directly in solution. They add benzonitrile in this solution, allowing graphene to be separated without producing excess functional groups, so that the obtained graphene is free from defects. The graphene produced by this method can either be cut without defect and can also obtain a specific electrical property by setting the number of carriers. The quality of graphene produced by this method is much higher than any other method in the past. It's gratifying that the technology is very efficient and the cost is low. Professor Hirsch said the discovery was a breakthrough for experts in the reduction of graphene synthesis. According to this discovery, experts expect to make great progress in the method of making graphene by wet chemical stripping. For example, a defective graphene can be cut for semiconductors and inductors. In addition, the method designed by the FAU researchers also has another advantage: in the reaction, the reductive benzonitrile molecules become red as long as they do not contact oxygen or water. According to the discoloration, the researchers can easily count the carriers by the absorption measurement. Before, the number of carriers can only be calculated by measuring the voltage. This means that graphene and battery researchers now have a new way to measure the state of the charge. According to the statistics, China has the largest graphene research team in the world and the number of 1/3 patents in the world. At present, nearly 20 graphene industrial parks have been built or have been built, and more than 300 enterprises are engaged in the production and development of graphene and related products or provide equipment for them. The industry of graphene is transition from basic research to industrialization in China. It is possible to realize industrialization in the fields of touch screen and flexible electronic device in the future. Andre Haim, a physicist who won the Nobel prize in physics for the discovery of graphene, said that in the world, there is a common problem in the application of patents, that is, the number of patents applied by scientific research institutions far exceeds that of the enterprise, but it is really less commercialized. At present, China is in the leading position in commercial applications, which is mainly due to the great importance and support of China in the development of graphene. At present, in the world to seek a new round of science and technology and industrial upgrading of the big background, the application of graphene materials has been promoted to the national strategic height by many countries. At present, such as Britain, the United States, Spain, South Korea and other countries have invested a lot of money in the research and development of graphene. "China made 2025" technical roadmap is clearly pointed out that the Chinese graphene industry "formed a hundred billion industrial scale in 2020, the overall industrial scale in 2025 over hundreds of billions of" development goals.