Developing Mechanism of Nanowires Discovered
Developing Mechanism of Nanowires Discovered
  • Reporter Lee Suh-young
  • 승인 2010.11.03 22:03
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POSTECH’s Professor Sang Ho Oh  from the Departement of Materials Science and Engineering and his research team have uncovered the developing mechanism of nanowires. Prof. Oh observed the nanowires’ VLS (Vapor-Liquid-Solid) developing mechanism, and published  the results in the online edition of Science on Oct. 21.

The VLS mechanism allows the growth of one-dimensional structures, such as nanowires, from chemical vapor deposition; introducing a catalytic liquid alloy phase, it can rapidly adsorb vapor to supersaturation levels.

Nanowires are utilized in transistors, memory, chemical sensors, and several other areas. While those manufacturing technologies have been actively  developed, the developing mechanism from atoms to nanowires has been veiled because of experimental difficulties.

In order to track the movement of atoms, Prof. Oh developed sapphire nanowires by VLS, and observed them through an in-situ Transmission Electron Microscope (TEM). In this experiment, it was revealed that by successively providing oxygen, sapphire nanowires melt their bodies and become crystalline at the triple point where three phases (gas, liquid, and solid) coexist.

This research is significant in that a developing mechanism of nanowires was discovered. “Because this reaction occurs at one-second cycle in the nano scale, it has not been observed until we used in-situ TEM technology,” said Prof. Oh.

He explained, “Atoms work smartly to minimize unnecessary energy consumption. Through partial development and liquefaction, they obtain enough oxygen for developing crystalline surfaces.”