Korea Develops Flexible LED Materials

At present, many electronic and optoelectronic materials made of organic materials have good flexibility and are easy to change shape. At the same time, inorganic compounds that are not easily deformable exhibit strong performance in the manufacture of optical, electrical, and mechanical components. However, due to technical reasons, it is difficult for both to complement each other, and inorganic compound semiconductors with excellent functions have encountered obstacles to development due to their inflexible characteristics.

Fortunately, the combination of gallium nitride and graphene has partially achieved the ideal of combining strong and strong, and a light-emitting diode (LED) material capable of "deformation" has been born. According to a recent report, a research team led by Professor Iguchi Te, a professor at the Seoul National University in South Korea, placed a miniature GaN rod on the surface of a graphene film to create a bendable and retractable LED material. This means that LED products such as bendable displays may appear in our lives. Details of the research results were published in the "Applied Physics Letters" published by the American Institute of Physics (AIP). Materials magazine.

The characteristics of the ultra-thin graphene film make it an ideal substrate material for the group. It has excellent flexibility and excellent mechanical strength, and can maintain excellent physical and chemical stability even at high temperatures exceeding 1000°C. The stable and inactive graphene surface provides a small amount of nucleation sites, which is conducive to the growth of gallium nitride on the graphene surface into an ideal three-dimensional micro-rod structure.

“The microscopic and even nanostructured GaN, due to its high density of integration and outstanding color-changing luminescence, has gained widespread attention in the materials research community.” Iguchier added, “When they are combined with graphene-based panels, , will be able to withstand the mechanical deformation, and further enhance the application value."

In order to really make micro LEDs on a graphene-based board with GaN, the team used a catalyst-free organometallic chemical vapor deposition (MOCVD) method that was invented in 2002. Iguchi said: "The key to this technology is to control the doping while maintaining a high degree of crystallinity so that it forms heterostructures and quantum structures and grows vertically aligned on the underlying substrate."

Subsequently, the team tested the specially fabricated GaN LED thin rods on the surface of graphene and found that this flexible LED has excellent and reliable light-emitting ability even after being energized, even at 1,000 bends. After testing, the luminescence properties of the material are still not significantly degraded. Maybe not long afterwards, LED screens that can be folded freely will appear in the streets and even wear on ourselves.

This achievement is undoubtedly a major technological breakthrough, and has also found possible means for large-scale, low-cost industrial production for the next generation of electronic and optoelectronic devices. The extensive application of graphene films in the field of materials will also give birth to more powerful and powerful materials that will bring us closer to the new era.