Material engineering at the atomic level brings breakthroughs in carbon nanotube technology

As devices continue to be manufactured on smaller and smaller scales, scientists are seeking to develop methods for material engineering at the atomic level
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In a breakthrough report published in Nature Communications, researchers from the Pioneer Research Cluster of the Institute of Physics and Chemistry and the Advanced Photonics Center of the Institute of Physics and Chemistry, together with their collaborators, developed a "dry transfer technology" "The method, that is, a technology that does not use solvents supplemented by precise positioning of optical quality carbon nanotubes
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? Carbon nanotubes are a very promising material type with potential uses in applications such as light-emitting diodes, single-electron transistors, or single-photon sources
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They are essentially tubes made of graphene twisted in a specific way, and the way they are twisted is critical to allow the desired properties to appear
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Creating a device with the required characteristics requires precise manipulation of the position and orientation of the nanotube, as well as a characteristic called "chirality", which describes the degree to which it is distorted
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However, it has been difficult to accurately manipulate molecules so far, because the use of solvents or high-temperature treatment inevitably makes the nanotubes dirty and hinders their optical properties
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To solve this problem, researchers are looking for a way to design nanotubes without using solvents
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They tried to use anthracene, a chemical extracted from petroleum, as a sacrificial material
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They processed nanotubes on a scaffold made of anthracene, brought it where they wanted to go, and then used heat to sublime the anthracene, leaving the nanotubes in an optically original state
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They also developed a method to monitor the photoluminescence of the nanotubes during the transfer process to ensure that the nanotubes with the required optical properties are placed in the correct position
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The team confirmed that after the dry transfer, the remaining nanotubes have bright photoluminescence with a brightness that is 5000 times that of the original molecule, a quality that makes them ideal for optical devices
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In addition, the team was able to precisely position the nanotubes on top of a nano-scale optical resonator, enhancing the characteristics of light emission
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According to Keigo Otsuka of the Pioneer Research Group of the Institute of Physics and Chemistry, the first author of the paper, "We believe that this technology will not only help create nanodevices with desired characteristics from carbon nanotubes, but also help Build a high-end system based on the free combination of atomic layer materials and other nanostructures
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" "In addition," said Yuichiro Kato, the head of the group, "this technology has the potential to promote the development of atomic definition technology beyond nanotechnology.
In this technology, materials with atomically precise structures are used as building blocks to design and construct functions that are different from existing materials
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