For the purpose of changing the earth bulb to graphene?

In the past few years when LED entered the public view, technological progress and the enhancement of human needs played a large part. Even the traditional lighting without damage is gradually replaced by white LED. Because white LED has huge advantages in terms of power consumption and lighting. Although the popularity of LED products has reached such a level, it still faces this huge problem, that is, the rare earth elements that make LED are less and less. To solve this problem, researchers are studying a new LED made from rare earth elements to rewrite the white LED technology with graphene. The current white LED, also known as white light diode, its white light is mainly realized by two ways: single crystal and polycrystalline. Polycrystal means that different colors of LED are encapsulated together, and white color is displayed through complementary colors. And the way of single crystal is relatively simple. The mixture of yellow and blue LED of phosphor by single blue LED and its yellow phosphor will give the effect of white light visually. The above two processes can not avoid using rare earth elements. Recently, researchers at National Tsinghua University published an article in "ACS Nano", which pointed out that the researchers made use of materials other than rare earth to produce LED products that can produce white light. On the basis of alkali strontium, the LED has built a metal organic framework (MOF), which combines graphene and other materials on the top and bottom of MOF to form LED that can directly emit white light. MOF is a very promising material, which is formed by the coordination of metal ions and organic materials. In the past 20 years, it has been widely used in chemical separators, drug delivery, gas storage, catalysis and other fields. In the field of optoelectronics, it is hard to see this material, because MOF is generally porous and has poor electrical conductivity. In the early stage of research, white light MOF is basically composed of different kinds of rare earth elements. In order to solve the above problems, we should use better conductive elements, but at the same time, this element also needs to emit the light of the frequency band under excitation. The researchers used organic ligands and used alkaline earth strontium to prepare MOF materials. On the surface of MOF, transparent electrode graphene is added to improve carrier mobility and optical properties. Because of the excellent thermal conductivity of graphene, the new white light diode has better thermal conductivity. At the periphery of MOF, researchers also combined graphene, silica and Zinc Oxide. Enable it to shine in electric drive. The use of MOF materials to create light-emitting devices has given people a whole new way of thinking. The test results show that as the light-emitting device, the display range of light is very close to natural light (green dot in the picture). As a semiconductor device, its stability is also good. During the two months of the test, there is almost no performance degradation. In addition to performance, the environmental significance of this material is more important. Because the new LED does not use rare elements, greatly reduces the use of rare earth elements, and fewer rare earth elements, it is very important to reduce the use of rare earth elements now. At the same time, this can also reduce the environmental pollution caused by the exploitation of rare earth elements. The light emitted from the new material is very close to the natural light, and there will be no strong blue light. The luminous efficiency is greatly improved because it does not obscured other colors and light. Electricity consumption will be reduced, and greenhouse gas emissions will also be reduced. From the common bulb to the LCD panel in the electronic equipment, more and more sets off to start using LED as the light source. No matter from the protection of resources, or from the protection of the environment, the emergence of the new white LED technology is excellent.