Improvement in a-Si:H properties by inert gas plasma treatment
- Sanyo Electric Co., Ltd., Hirakata, Osaka (Japan). New Materials Research Center
The modification of surface reactions with an inert gas plasma treatment method has been investigated for the first time in order to improve the properties of a-Si:H for solar cells. The deposition of a thin a-Si:H layer and exposure to inert gas plasma such as He, Ar or Xe were repeated by using RF plasma CVD at a substrate temperature of 200 C. It has been found that the hydrogen content (C{sub H}) can be controlled in a wide range from about 18 atomic% to about 35 atomic%, although it is a hydrogen-free process. Experimental results show that the change in C{sub H} of a-Si:H films is mainly determined by the decrease in C{sub H} of the treated a-Si:H surface and the increase in C{sub H} of the a-Si:H deposited on the treated surface. Furthermore, the plasma treatment probably promotes the surface reaction, which reduces SiH{sub 2}/SiH and C{sub H}. Consequently, wide-gap (1.64 eV by ({alpha} h {nu}){sup 1/3} versus h {nu} plots, 1.75--1.85 eV by Tauc`s plot) a-Si:H films with high stabilized photoconductivity (>10{sup {minus}5} {Omega}{sup {minus}1}cm{sup {minus}1} under AM-1, 100 mW/cm{sup 2} irradiation) have been obtained by the inert gas plasma treatment method.
- Sponsoring Organization:
- New Energy and Industrial Technology Development Organization, Tokyo (Japan)
- OSTI ID:
- 527651
- Report Number(s):
- CONF-960401--; ISBN 1-55899-323-1
- Country of Publication:
- United States
- Language:
- English
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