Synchrotron radiation photoemission study of metal overlayers on hydrogenated amorphous silicon at room temperature
In this dissertation, metals deposited on a hydrogenated amorphous silicon (a-Si:H) film at room temperature are studied. The purpose of this work is mainly understanding the electronic properties of the interface, using high-resolution synchrotron radiation photoemission techniques as a probe. Atomic hydrogen plays an important role in passivating dangling bonds of a-Si:H films, thus reducing the gap-state distribution. In addition, singly bonded hydrogen also reduces states at the top of the valence band which are now replaced by deeper Si-H bonding states. The interface is formed by evaporating metal on an a-Si:H film in successive accumulations at room temperature. Au, Ag, and Cr were chosen as the deposited metals. Undoped films were used as substrates. Since some unique features can be found in a-Si:H, such as surface enrichment of hydrogen diffused from the bulk and instability of the free surface, we do not expect the metals/a-Si:H interface to behave exactly as its crystalline counterpart. Metal deposits, at low coverages, are found to gather preferentially around regions deficient in hydrogen. As the thickness is increased, some Si atoms in those regions are likely to leave their sites to intermix with metal overlayers like Au and Cr. 129 refs., 30 figs.
- Research Organization:
- Ames Lab., IA (USA)
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 6766231
- Report Number(s):
- IS-T-1409; ON: DE91000740
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360602* -- Other Materials-- Structure & Phase Studies
AMORPHOUS STATE
BREMSSTRAHLUNG
CHROMIUM
DEPOSITION
ELECTROMAGNETIC RADIATION
ELECTRONIC STRUCTURE
ELEMENTS
EMISSION
GOLD
INTERFACES
METALS
PHOTOEMISSION
RADIATIONS
SECONDARY EMISSION
SEMIMETALS
SILICON
SILVER
SURFACES
SYNCHROTRON RADIATION
TRANSITION ELEMENTS
VALENCE