Structural Changes in a-Si:H Films Deposited on the Edge of Crystallinity

Conference · Mon May 24 04:00:00 EDT 1999

DOI:https://doi.org/10.1557/PROC-557-269· OSTI ID:12223

Mahan, A H ^[1]; Yang, J; Guha, S ^[2]; Williamson, D L ^[3]

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1. National Renewable Energy Laboratory, Golden, CO (US)
2. United Solar Systems Corp., Troy, Michigan (US)
3. Colorado School of Mines, Golden, Colorado (US)

Using infrared, H evolution and x-ray diffraction (XRD), the structure of high H dilution, glow discharge deposited a-Si:H films ''on the edge of crystallinity'' is examined. From the Si-H wag mode peak frequency and the XRD results, we postulate the existence of very small Si crystallites contained within the amorphous matrix, with the vast majority of the bonded H located on these crystalline surfaces. Upon annealing at ramp rates of 8-15(degree)C/min, a H evolution both of which are far below those observed for a Si:H films grown without H dilution using similar ramp rates. While the crystallite volume fraction is too small to be detected by XRD in the as-grown films, these crystallites catalyze the crystallization of the remainder of the amorphous matrix upon moderate annealing, thus explaining the existence of the low temperature H evolution peak.

• Research Organization: National Renewable Energy Lab., Golden, CO (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC36-99GO10337
• OSTI ID: 12223
• Report Number(s): NREL/CP-520-26374
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
A-SI:H
AMORPHOUS SILICON
ANNEALING
CRYSTALLINITY
CRYSTALLIZATION
DILUTION
GLOW DISCHARGES
PHOTOVOLTAICS
SOLAR CELLS
X-RAY DIFFRACTION