Ultra-Light Amorphous Silicon Cell for Space Applications

• Main Authors: Wyrsch, N., Domine, D., Freitas, F., Feitknecht, L., Bailat, J., Ballif, C., Poe, G., Bates, K., Reed, K.
• Format: Conference Proceeding
• Language: English
• Subjects: Amorphous silicon; Fabrication; Glass; III-V semiconductor materials; Lighting; Photovoltaic cells; Polyimides; Polymer films; Semiconductor films; Substrates
• ISSN: 0160-8371
• DOI: 10.1109/WCPEC.2006.279837

For space applications, solar cells should be optimized for highest power density rather than for highest efficiency. In this context, relatively low efficiency thin-film solar cell may well surpass multi-junction III-V based solar cells if they can be made thin enough. In thin-film solar cells the power density is mostly limited by the substrate. The introduction of ultra-thin polymeric substrates is the key for decreasing the cell mass. In this work, a very thin polyimide film LaRCtrade-CP1 was used as substrate or superstrate for amorphous silicon solar cell fabrication. CP1 films were either fixed on a glass carrier or spin coated onto a glass carrier coated with a release agent. By depositing amorphous silicon cells on 6 mum thick CP1 films, a power density of 2.9 W/g under AM1.5g and of 3.9 W/g (estimated) under AM0 illumination spectra was achieved, in substrate (n-i-p) configuration (for a cell area of ca. 0.25 cm 2 ). A similar cell deposited in superstate (p-i-n) configuration exhibits a record power density of 3.2 W/g under AM1.5g and an estimated value of 4.3 W/g under AM0 illumination spectra. Release of the finished solar cells from the glass carrier was also tested