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October 19, 2018 03:00
IBS, polycrystalline metal sheet
Achieved high quality single crystal sheet metal
Manufacturing costs less than one thousandth
High performance economic catalyst, waiting for the solar cell
Korean researchers have developed a technology to replace an inexpensive polycrystalline metal sheet with a monocrystalline sheet of metal capable of implementing high performance electronic devices. It is possible to manufacture a high quality monocrystalline metal sheet at a lower cost than conventional and can be applied to various metals such as copper (Cu) and nickel (Ni), cobalt (Co) and platinum ( Pt) Catalysts, etc.
The team, led by Professor Shin, Hyung-joon of UNIST and Professor Sungkyunkwan University, is badociated with the team of Professor Yu Won-jong, professor at Sungkyunkwan University, to develop high-value monocrystalline metal sheets with the help of a low-cost commercial polycrystalline metal sheet. He has developed a technology that makes it easy to make sheets in a large area. It was published online in the 19th edition of the international journal "Science & # 39 ;. "It was published in the week following the publication of the document," he said, "and has been evaluated as a decisive research result."
Non-contact heat treatment method for easily producing a monocrystalline metal sheet with a polycrystalline metal sheet We focused on the phenomenon that the arrangement of atoms becomes uniform by applying a high temperature close to the melting point. – Institute for Basic Research Provided (IBS)
Polycrystalline crystals are composed of numerous crystalline grains with irregular arrangement of atoms. There are boundaries between the intermediate grains, so the structure and properties are not uniform. On the other hand, a single crystal is a crystal composed of a monocrystal in which atoms are regularly arranged. There is no boundary between the crystal grains and it has excellent physical properties such as electrical conductivity and resists oxidation and corrosion. The first author of the article, Jung Sung-whan, researcher at the IBS (postdoctoral researcher at UNIST), said: "For example, when a panel of solar cells is made of the same metal, the maximum efficiency of the polycrystalline solar cell is only 20%%, "he said.
However, single crystals have only been used in a limited number of areas because of the high manufacturing cost and the difficulty of manufacturing large area semiconductors. For example, the cost of producing a polycrystalline copper sheet is 38 won per, but monocrystalline copper sheet reaches 180,000 won per. Even the same sheet of metal is a thousand times different in price.
Researchers developed a new non-contact heat treatment process that reduced the cost of single-crystal sheet metal fabrication to one-thousandth of a million. This process is very simple in that the polycrystalline metal sheet is suspended in the air, the hydrogen gas is poured and the heat treatment is carried out. We have discovered that the atomic arrangement of the irregular sheet changes regularly when it is subjected to high temperatures near the melting point and we have chosen the contactless approach to divert or deform the liner. arrangement of atoms.
"We found that among the grains of the polycrystalline metal sheet, the grains with the lowest surface energy are combined around the grains to form a single crystal, which eventually becomes the single crystal."
The process of a polycrystalline metal sheet becomes monocrystalline. Crystalline grains around the crystalline grains with the lowest surface energy are combined to form a monocrystalline grain. – Institute for Basic Research Provided (IBS)
The researchers produced monocrystalline copper sheets up to 32 cm 2 (4 x 8 cm), the largest surface area that can be produced in the laboratory. Detailed badysis of the structure and properties of the monocrystalline copper foil revealed that all the atoms were uniformly aligned in one direction and that the electrical resistance was 7% lower than that of the polycrystalline copper foil used as the raw material. Monocrystalline large-area sheets could consist of other metals such as nickel, cobalt, platinum and palladium.
The researchers also succeeded in producing monocrystalline graphene, of better electrical quality than polycrystalline graphene, by the size of the substrate using a sheet of monocrystalline metal. Graphene, called "dream material", is a two-dimensional material consisting of a layer of carbon atoms. "Thanks to the monocrystalline metal sheet, we can manufacture high quality two-dimensional materials over a large area," Jin said. We plan to continue research in various areas such as solar cells and catalysts. "
"The surface of the metal foil may be large enough depending on the area of application at the stage of practical application," Lou said often. "Monocrystalline graphene can also be made to the size of the substrate." "Despite the efforts of many researchers, monocrystalline sheet metal fabrication technology has more weight because it is a technology that has not worked for decades," he said. he declares. "The discovery of silicon single crystal growth technology is now in various areas – I will change the world."
He was named winner of the 2018 Citation Award by Claribate Analytics (formerly Thomson Reuters Intellectual Property Sciences), a global academic information society located in the United States. Yuri Koko, professor at the American University Drexel, and Professor Parethis Simon France, Paul Sabatier, were selected as potential candidates for the Nobel Prize in Physics. Has contributed to the understanding and development of carbon-based materials, including energy storage, and has contributed to important discoveries to elucidate the operating mechanism of supercapacitors.
October 19, 2018 03:00
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