We have succeeded in the synthesis of a bilayer silicene, which is a new allotrope of silicon, containing four-, five- and six-membered sp3 silicon rings, after treating calcium-intercalated monolayer silicene (CaSi2) with a BF4- -based ionic liquid. The bilayer silicene has high chemical stability by reducing the number of unsaturated silicon bonds. Additionally, the bandgap opens to 1.08 eV and is indirect; this is in contrast to monolayer silicene which is a zero-gap semiconductor. The findings provide a basis for future studies for electronic devices and electrodes of batteries.
Research Area “New Materials Science and Element Strategy”
Research Theme “Development of transition metal free anion batteries”
Ritsuko Yaokawa, Tetsu Ohsuna, Tetsuya Morishita, Yuichiro Hayasaka, Michelle J. S. Spencer, and Hideyuki Nakano. “Monolayer-to-bilayer transformation of silicenes and their structural analysis”. Nature Communications, Published online 05 February 2016, doi: 10.1038/ncomms10657.
Hideyuki Nakano, Ph.D.
Principal Researcher, Program Manager, Functionalized Low-Dimensional Silicon Program, Strategic Innovation Research-Domain, TOYOTA Central R&D Labs., Inc.
Sofia Saori Suzuki
Green Innovation Group, Department of Innovation Research, JST