To make use of graphene for the earth's light bulb?

In the years in which LED entered the public vision, the progress of technology and the improvement of human needs have played a great part. Even the traditional household lighting, which is not damaged, is gradually replaced by the white LED. Because white light LED devices have great advantages in power consumption and lighting effects. Although the LED product is so popular, it still faces this huge problem, that is, the rare earth element of the raw material for making LED is becoming less and less. To solve this problem, researchers are studying a new LED, made from rare earth elements, to rewrite the current white light LED technology with graphene. The current white light LED is also called white light diode, and its white light is mainly realized in two ways, single crystal and polycrystal. Polycrystalline is meant to be encapsulated by different colors of LED, and the white color is displayed in a complementary color. The single crystal is simpler. The combination of a single blue light LED and the yellow phosphor on its surface, the yellow and blue light LED of the phosphor, will make the visual effect of white light. The above two processes can not 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 used materials other than rare earth elements to produce white - light LED products. Based on the alkali metal strontium, this LED builds a metal organic framework (MOF), which combines graphene and other materials on the MOF, forming a LED that can directly emit white light. MOF is a very promising material. It is formed by the combination of metal ions and organic materials. In the past 20 years, it has been widely used in the fields of chemical separator, drug delivery, gas storage, catalysis and so on. It is very difficult to see this material in the field of optoelectronic because MOF is generally porous and poor in conductivity. In the early research process, the MOF, which could be emitted from white light, was basically combined with different kinds of rare earth elements. In order to solve the above problems, we should use the elements with good electrical conductivity, but at the same time, this element will also be able to launch the light of the emission band. The researchers used organic ligands and used the alkaline earth metal strontium to prepare the MOF material. On the surface of MOF, the transparent electrode graphene is added to improve the carrier mobility, and the optical properties are not particularly affected. Due to 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. Make it light in electric drive. The use of MOF materials to make light emitting devices gives people a new idea. The test results show that as a light-emitting device, the light is very close to the natural light (the green point in the map). As a semiconductor device, its stability is better. During the two months of the test, there is little performance decline. In addition to the performance, the environmental significance of the material is more important, because the new LED does not use rare elements, a large number of rare earth elements are reduced, rare earth elements are becoming less and less now, reducing the use of rare earth elements is 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 there will not be a 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. A growing number of LCD panels from common bulbs to electronic devices are starting to use LED as a light source. Both from the protection of resources or from environmental protection, the new white light LED technology is excellent.