X-ray spectroscopic study of electronic structure of amorphous silicon and silicyne

X-ray and ultrasoft X-ray spectroscopy have both been applied to study Si K β and Si L 23 emission spectra of crystalline silicon ( c -Si), amorphous hydrogenated silicon ( a -Si:H), and silicyne (a new allotropic linear-chain form of silicon). Si L 23 spectra of silicyne show three peaks instead of two observed in crystalline and amorphous silicon. The third peak lies in the high-energy range at 95.7 eV, its intensity constituting ∼75% of that of the main peak. An additional peak is also observed in the short-wavelength part of the Si K β spectrum. Such a significant difference in shape between the X-ray spectra of amorphous silicon and silicyne is attributed to the existence of a pronounced π component in the chemical bonds between silicon atoms in silicyne.