We have determined the valence and conduction band density of states (DOS) in a-Si:H by fitting the dielectric spectra measured by spectroscopic ellipsometry. The films are grown by reactive dc magnetron sputter deposition. We find that hydrogenation reduces the states near the valence band edge, and increases those deeper in the valence band. In addition, SiH anti-bonding states are observed about 1.5 eV above the conduction band edge. These changes are systematic with hydrogen content in the film.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry