For earth bulbs, use graphene?

During the years of LED's entry into the public vision, technological progress and the improvement of human needs played most of the role. Even the traditional household lighting, which is not damaged, is gradually being replaced by white light LED. Because the white LED device has a huge advantage in the power and lighting effects. Although the popularity of LED products to such a point, but still face this huge problem, that is, the production of raw materials LED rare earth elements less and less. To solve this problem, researchers are working on a new LED that avoids the rare earth elements and rewrites the present white LED technology with graphene. The current white light LED, also known as white light diode, its white light mainly by single crystal, polycrystalline two ways to achieve. Polycrystal means different colors of LED wrapped together, through the color complementary way to show the white light. The single crystal approach is simple, and the yellow light and blue LED of the phosphor, which combines a single blue LED with its surface yellow phosphor, gives the visual effect of white light. None of the above two processes will be able to avoid the use of rare earth elements. Recently, researchers at the National Tsinghua University published an article in ACS Nano, which pointed out that researchers using materials other than rare earth to produce LED products that can emit white light. The LED, based on alkali metal strontium, has constructed a metal organic framework (MOF) that combines graphene and other materials on top and bottom of the MOF to form a LED that emits white light. MOF is a very promising material that is formed by the coordination of metal ions with organic materials. In the past 20 years, it has been widely used in the fields of chemical separation, drug delivery, gas storage, catalysis and so on. In the field of optoelectronics, it is difficult to see this material, because MOF is generally porous, conductive poor. In the early studies, MOF, which emits white light, is basically made up of different kinds of rare earth elements. In order to solve the above problems, the elements with better conductivity should be used, but at the same time, the element should also emit light at the excitation frequency band. The researchers used organic ligands to prepare MOF materials using alkaline earth metal strontium. The addition of a transparent electrode to graphene on the MOF surface improves carrier mobility and does not particularly affect optical performance. 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 assembled graphene, silica, and Zinc Oxide. Cause it to glow in an electric drive. The use of MOF materials to make light-emitting devices has given people a completely new idea. The test results show that as the light emitting device, display range is very close to the natural light (green point map), as a semiconductor device, its stability is better, during the two months of testing, there is almost no performance degradation. In the performance, the more important the material environmental significance, due to the new LED without the use of a large number of rare elements, to reduce the amount of rare earth elements, rare earth elements and less now, reduce the use of rare earth elements are very important. At the same time, it can also reduce the environmental pollution caused by the exploitation of rare earth elements. The light emitted by the new material is very close to the natural light and does not appear to have strong blue light. The luminous efficiency can be greatly improved without blocking other colors. Reduce the power consumption, greenhouse gas emissions will also be reduced. From the LCD panel more common bulbs to electronic equipment in the equipment to start using LED as light source, no matter from the protection of resources, or from the protection of the environment, the emergence of new white LED technology are excellent.