Preparation and Properties of Amorphous Cadmium Silicon-Arsenic Thin Films.
Available from UMI in association with The British Library. Requires signed TDF. Amorphous thin films of Cd-Si-As have been prepared over a wide range of compositions by radio-frequency sputtering in an argon/hydrogen plasma and their properties studied by various techniques. Transmission electron microscope investigations confirmed that the films were amorphous even though many of the compositions were outside the glass-forming region. Scanning electron microscopy showed that none of the samples were phase separated. Optical absorption measurements showed that the optical band-gap changed from 1.7eV to 1.2eV as the silicon content was reduced from 70% to 13%. Conduction was found to be in extended states over the entire temperature range of measurements of electrical conductivity. The thermopower data indicated that the majority carriers were holes at all compositions and temperatures. The technique of Extended X-ray absorption fine structure (EXAFS) has been used to determine that the alloys are four-fold coordinated and that the bonding is not entirely random. The implication that the Si-As bonding orders the structures was confirmed by the infrared transmission data.
- Pub Date:
- September 1987
- Chemistry: Physical; Physics: Condensed Matter