Hydrogen-induced modification of the medium-range structural order in amorphous silicon films
- Department of Materials Science and Engineering and the Coordinated Sciences Laboratory, University of Illinois at Urbana-Champaign, 1-109 Engineering Sciences Building, 1101 West Springfield Avenue, Urbana, Illinois 61801 (United States)
We use fluctuation electron microscopy to determine changes in the medium-range structural order of un-hydrogenated amorphous silicon thin films after they are exposed to atomic hydrogen at a substrate temperature of 230 deg. C. The films are deposited by magnetron sputtering at either 230 or 350 deg. C substrate temperature to obtain starting states with small or large initial medium-range order, respectively. The in-diffusion of atomic hydrogen causes the medium-range order to decrease for the small initial order but to increase for the large initial order. We suggest that this behavior can be understood in terms of classical nucleation theory: The ordered regions of small diameter are energetically unstable and can lower their energy by evolving towards a continuous random network, whereas the ordered regions of large diameter are energetically stable and can lower their energy by coarsening towards the nanocrystalline state.
- OSTI ID:
- 20706489
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 24 Vol. 87; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Increased medium-range order in amorphous silicon with increased substrate temperature
Unexpected short- and medium-range atomic structure of sputtered amorphous silicon upon thermal annealing