Electronic structure and properties have been compared for amorphous germanium selenide films with compositions near GeSe2 to GeSe3, and prepared by either plasma-enhanced chemical vapour deposition (PECVD) of GeH4 and H2Se mixtures, or by thermal evaporation of bulk germanium selenide compounds. X-ray photoelectron spectroscopy (XPS) is used in conjunction with photo-and dark conductivity measurements. XPS spectra from Ge 3d and Se 3d core levels, and of the valence band, reveal no significant difference in electronic structure, but the electrical measurements point to a different position of the Fermi level in the two types of material. It is suggested that PECVD produces a distribution of localized gap states which pushes the Fermi level closer to the transport band.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry