Studies on backside Al-contact formation in Si solar cells : fundamental mechanisms : preprint /
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| Format: | Government Document eBook |
| Language: | English |
| Published: |
[Golden, Colo.] :
National Renewable Energy Laboratory,
[2009]
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| Series: | Conference paper (National Renewable Energy Laboratory (U.S.)) ;
NREL/CP-520-45001. |
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| Online Access: | https://purl.fdlp.gov/GPO/LPS112713 |
| Abstract: | We have studied mechanisms of back-contact formation in screen-printed Si solar cells by a fire-through process. An optimum firing temperature profile leads to the formation of a P-Si/P+-Si/ Si-Al eutectic/agglomerated Al at the back contact of a Si solar cell. Variations in the interface properties were found to arise from Al-Si melt instabilities. Experiments were performed to study melt formation. We show that this process is strongly controlled by diffusion of Si into Al. During the ramp-up, a melt is initiated at the Si-Al interface, which subsequently expands into Al and Si. During the ramp-down, the melt freezes, which causes the doped region to grow epitaxially on Si, followed by solidification of the Si-Al eutectic. Any agglomerated (or sintered) Al particles are dispersed with Si. Implications on the performance of the cell are described. |
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| Item Description: | Title from title screen (viewed February 27, 2009). "Presented at the Materials Research Society (MRS), Fall Meeting 2008, Boston, Massachusetts, December 1-5, 2008." "February 2009." Electronic resource. |
| Physical Description: | 6 pages : digital, PDF file. |
| Format: | Mode of access: Internet from the NREL web site. Address as of 5/15/09: http://www.nrel.gov/docs/fy09osti/45001.pdf ; current access available via PURL. |