Title:	Polymorphous and Nanocrystalline Silicon Thin-Film Solar Cells Deposited at 150°C on Plastic Substrates
Author(s):	P. Alpuim, G.M. Junior, S.A. Filonovich, P. Roca i Cabarrocas, J.-E. Bouree, E.V. Johnson, Y.M. Soro
Keywords:	Flexible Substrate, a-Si:H, Thin Film Solar Cell
Topic:	Thin Films
Subtopic:	Amorphous and Microcrystalline Silicon
Event:	23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain
Session:	3AV.2.34
Pages:	2455 - 2458
ISBN:	3-936338-24-8
Paper DOI:	10.4229/23rdEUPVSEC2008-3AV.2.34
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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A study of the fabrication of thin-film silicon solar cells in the p-i-n superstrate diode configuration on plastic substrates at a temperature of 150 ºC, using different absorbing i-layers, is presented. A typical solar cell structure in this work comprises the following successive layers: PEN/GZO/p/buffer/i/n/metal. GZO is a transparent conductive window layer made of Zinc Oxide doped with Gallium and buffer is a high-bandgap ~10 nm-thick amorphous silicon layer. Flexible solar cells deposited entirely by radio-frequency plasma enhanced chemical vapour deposition on PEN had a conversion efficiency of 5.0%, JSC = 11.2 mA/cm2, and VOC = 0.830 V. Similar solar cells on PEN but with the i-layer deposited by hot-wire chemical vapor deposition had efficiency 4.53%, JSC = 12.7 mA/cm2, and VOC = 0.699 V. Based on the spectral response of the solar cells and on their I-V characteristics under different light levels, it is concluded that the efficiency of the devices is limited by recombination in the i-layer and by losses in the long wavelength part of the spectrum. Devices fabricated on PEN and on Asahi-U glass have comparable characteristics. However, the best fill factor obtained on PEN is 55.6% whereas on glass it is 60.1%. Nanocrystalline solar cells on PEN have high JSC (17.2 mA/cm2) but very poor FF (32.7%).