Thin film polycrystalline silicon solar cells [electronic resource]
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| Online Access: |
Online Access |
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| Corporate Author: | |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Golden, Colo. : Oak Ridge, Tenn. :
National Renewable Energy Laboratory (U.S.) ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
1980.
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| Subjects: |
| Abstract: | During the present quarter efficiency of heterostructure solar cells has been increased from 13 to 13.7% for single crystal and from 10.3 to 11.2% for polysilicon. For polysilicon the improvements can be attributed to reductions in grid-area coverage and in reflection losses and for single crystal to a combination of reduction in grid-area coverage and increase in fill factor. The heterostructure cells in both cases were IT0/n-Si solar cells. Degradation in Sn0₂/n-Si solar cells can be greatly reduced to negligible proportions by proper encapsulation. The cells used in stability tests have an average initial efficiency of 11% which reduces to a value of about 10.5% after 6 months of exposure to sunlight and ambient conditions. This small degradation occurs within the first month, and the efficiency remains constant subsequently. The reduction in efficiency is due to a decrease in the open-circuit voltage only, while the short-circuit current and fill factor remain constant. The effects of grain-size on the Hall measurements in polysilicon have been analyzed and interpreted, with some modifications, using a model proposed by Bube. This modified model predicts that the measured effective Hall voltage is composed of components originating from the bulk and space-charge region. For materials with large grains, the carrier concentration is independent of the inter-grain boundary barrier, whereas the mobility is dependent on it. However, for small rains, both the carrier density and mobility depend on the barrier. These predictions are consistant with experimental results of mm-size Wacker polysilicon and ..mu..m-size NTD polysilicon. |
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| Item Description: | Published through SciTech Connect. 01/01/1980. "seri/pr-9077-1-t1" Feng, T.; Ghosh, A. K.; Eustace, D. J.; Maruska, H. P. Exxon Research and Engineering Co., Linden, NJ (USA). Advanced Energy Systems Labs. |
| Physical Description: | Pages: 33 : digital, PDF file. |