Paving Way for Paper-thin Displays
Researchers from the Korean’s KAIST institute developed a new process to produce graphene quantum dots that are equal in size and highly efficient in emitting light. Quantum Dots potentially can be used to develop emissive flexible displays (similar to OLED displays), and this development may enable those displays to be graphene-based.
The process involves mixing salt, water and graphite and then synthesizing a chemical compound between layers of graphite. All the resulting quantum dots were 5 nanometer in diameter, and these QDs do not contain and heavy metals (like current commercial quantum dots). The process is reportedly easy to scale and should not be expensive.
A Korean research team has successfully developed high-quality graphene quantum dots that are equal in size and highly efficient in emitting light. This technology is expected to be used in developing paper-thin displays or displaying information in flexible materials.
The Korea Advanced Institute of Science and Technology (KAIST) announced on August 28 that a research team led by Jun Suk-woo, professor of the department of materials science and engineering at KAIST, has succeeded in making graphene quantum dots by mixing water and salt into graphite and then synthesizing a chemical compound between layers of graphite, in collaboration with professors Jo Young-hoon and Ryu Seung-hyup. Quantum dots are nanometer-sized round semiconductor nanoparticles that are very efficient at emitting photons very quickly.
They are receiving a lot of attention as a possible next-gen technology in quantum information and communications because of these properties. The diameter of the equally-sized graphene quantum dots was 5 nanometers. Unlike existing quantum dots, new ones are eco-friendly, since they do not require toxic materials like lead and cadmium. Moreover, it is possible to mass-produce newly-developed quantum dots at little cost, because they are made of easily-obtainable materials such as graphite, water, and salt.
In the past, it was difficult to commercialize graphene quantum dots, in that it was not easy to synthesize a large number of equal size. Another factor was low efficiency from the way the particles were put together. The team developed and confirmed the possibility of the commercialization of graphene quantum dot LEDs with more than 1000cd/m2 brightness using graphene quantum dots, which are brighter than displays for cell phones.
Professor Jun remarked, “The new quantum dots are not as efficient as existing LEDs in emitting lights. However, the characteristics of emitting lights can be improved further.” He added, “I hope that it will be possible to make paper-thin displays and exhibit information in soft materials like curtains using this method.” The research findings were first published online on August 20 by Advanced Optical Materials, a scientific journal published by Wiley-VCH.
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The researchers say that those gQDs could be used to develop LEDs that have a brightness of over 1000cd/m2. This is less efficient than current LEDs, but the researchers hope this technology can be further improved.
Source: Business Korea