Electronic Structure of Amorphous Si from Photoemission and Optical Studies

Photoemission from and optical studies of amorphous Si samples, carefully prepared to minimize the influence of defects, are reported. Photoemission yield and energy distribution curves were obtained from 5.5 to 11.7 eV and reflectance data were measured from 0.4 to 11.8 eV. Optical constants were determined by a Kramers-Kronig analysis. No evidence was found to indicate that the wave vector $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}$ provides a significant quantum number in amorphous Si.