Synthesis of a guest-free clathrate form of crystalline silicon was achieved by successive vacuum treatment and density separation of NaxSi136-based materials. The new allotrope of silicon has an open framework structure based upon slightly distorted tetrahedral atoms bound into five- and six-membered ring structures, and corresponds to a fully saturated and condensed fullerane-type solid. Theoretical calculations indicate that the new form of silicon should be a wide bandgap semiconductor. This prediction is borne out by experiment: electrical conductivity and optical absorption measurements yield a band gap of 1.9 eV, approximately twice the value of "normal" semiconducting silicon.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Sep 15 2000|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics