Title:	VHF PECVD Deposition of nc-Si – Material and Device Properties
Author(s):	A.E. Delahoy, T. Liu, G. Saraf, S. Guo, P. Delli Veneri, L.V. Mercaldo, I. Usatii, J.A. Cambridge, R. Kappera, A. Stavrides, L.N.J Rodriguez
Keywords:	Nanocrystalline, ZnO:Al, nc-Si:H, VHF PECVD, Hollow Cathode Sputtering
Topic:	Thin Films Solar Cells
Subtopic:	Amorphous and Microcrystalline Silicon Solar Cells
Event:	24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany
Session:	3BV.4.41
Pages:	2860 - 2866
ISBN:	3-936338-25-6
Paper DOI:	10.4229/24thEUPVSEC2009-3BV.4.41
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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Device-grade nanocrystalline silicon (nc-Si:H) has been prepared by a VHF (40.68 MHz) PECVD process. Appropriate recipes for the production by VHF PECVD of component cells (a-Si:H top stack cell and nc- Si:H bottom stack cell) suitable for tandem a-Si:H/nc-Si:H devices have been developed. The transport properties of the relevant i-layers were deduced from device measurements. The VHF nc-Si:H deposition parameters have been located in a phase diagram for thin Si:H growth. We have further started to link the spatial variation in plasma composition, nc-Si:H properties, and device performance. Making use of a mature VHF PECVD process at 100 MHz, tandem a-Si:/nc-Si:H devices were prepared on textured TCO films of ZnO:Al produced by hollow cathode (HC) sputtering. Using micro-Raman spectroscopy it was concluded that the 40.68 and 100 MHz processes produced nc-Si:H material having similar properties. For the 100 MHz devices, a peak in device efficiency was obtained at a crystalline volume fraction of 50-52 %. Device efficiencies were 9.9% on HC ZnO and 11.3% on a reference Type-U SnO2 substrate.