A research group led by Professor Hisanori Yamane and Assistant Professor Haruhiko Morito at Institute of Multidisciplinary Research for Advanced Materials, Tohoku University has newly developed double-helical silicon microtubes.

 Silicon is a major semiconductor material that supports a modern advanced information society. It is often used for solar cell materials because of recent environmental concerns. An industry that uses abundant and environmentally friendly silicon is expected to grow. Silicon used for semiconductor devices and solar cells is developed to be plates or films by solidifying silicon melts or chemical reaction of gas materials including silicon.  

　The research group has discovered double-helical silicon microtubes in a study on the new methods of silicon crystal formation and high purification of silicon using Sodium. The material used for synthesis is Natrium Silicide (NaSi), intermetallics.

 There are various spirals in daily lives such as vines, snails, DNA in body cells, spiral stairs, threads and ropes. The newly synthesized silicon is several dozen micrometers wide, several millimeters long, and spiral shaped made of dextrorsely or sinistrorsely twisted tubes whose ends are closed. Tube walls are made of fine crystals formed by the rapid evaporation of Sodium from NaSi melts. A number of holes several dozen nanometers in diameter are observed within the tubes.  The achievement is expected to lead to new applications including micro devices materials and catalyst carriers by using a specific shape and structure of silicon, and to contribute to the development of the silicon industry.

 The research result has been published online in Angewandte Chemie International Edition（http://www3.interscience.wiley.com/journal/26737/home） on April 12, 2010. The paper’s title is “Double-Helical Silicon Microtubes.” A patent on the synthesis method has been applied. The research has been conducted with the assistance of Grant-in-Aid for Young Scientists (Start-up) from Japan Society for the Promotion of Science　(JSPS).

More Information (Japanese)

[Contact]

Assistant Professor Haruhiko Morito

Institute of Multidisciplinary Research for Advanced Materials, Tohoku University

TEL: +81-22-217-5814

E-mail: morito*tagen.tohoku.ac.jp (Replace * with @)