For the earth bulb to graphene?

In the course of several years of LED entering the public view, the progress of technology and the improvement of the human demand have played the most part. Even if there is no damage to the traditional home lighting, has gradually been replaced by white LED. Because the white LED device has a huge advantage in power consumption and lighting effects.

Although the popularity of LED products to such a point, but still faces a huge problem, that is, the production of raw materials LED rare earth elements. In order to solve this problem, researchers are studying a rare earth element to avoid the production of a new LED, graphene rewrite the current white LED technology.

The current white LED, also known as white light diode, its white light mainly by single crystal, polycrystalline two ways to achieve. The meaning of multi crystal by the different colors of the LED package together, through the color complementary way to show the white light. And the way the single crystal is relatively simple, through a single blue LED and its surface yellow phosphor composition, the yellow and blue LED phosphor mixture, will have a visual effect of white light. The above two processes, can not avoid the use of rare earth elements.

Researchers at the National Tsinghua University recently published an article in the Journal ACS Nano, which notes that researchers have used materials other than rare earth elements to produce LED products that can emit white light. The LED based on alkali metal strontium, built a metal organic framework (MOF), in the upper and lower MOF were combined with graphene and other materials, constitutes a direct white light LED.

MOF is a very promising material, which 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 separators, drug delivery, gas storage, catalysis and so on. In the field of Optoelectronics is extremely difficult to see this material, because the general MOF porous, poor conductivity.

In the early stages of the study, the white light of the MOF is basically a combination of different kinds of rare earth elements together. In order to solve the above problems, we should switch to a good conductivity of the elements, but at the same time the element should be able to stimulate the emission of light in the frequency band. The researchers used organic ligands to prepare MOF materials using alkaline earth strontium.

On the surface of MOF, with the addition of transparent electrode graphene, the carrier mobility is enhanced, 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.

In the periphery of the MOF material, the researchers also assembled graphene, silica, Zinc Oxide. Make it possible to drive in electric light. The use of MOF materials to create light-emitting devices, gives people a new way of thinking.

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 there is no strong blue light. Because no other color light is blocked, the luminous efficiency can be greatly improved. Reduce power consumption, greenhouse gas emissions will 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.

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