Title:	Understanding Lifetime Degradation in Czochralski-Grown N-Type Silicon after High-Temperature Processing
Author(s):	D. Walter, B. Lim, R. Falster, J. Binns, J. Schmidt
Keywords:	Lifetime, Silicon (Si), Oxygen, n-Type, Precipitate
Topic:	WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Subtopic:	Silicon Feedstock, Crystallisation and Wafering
Event:	28th European Photovoltaic Solar Energy Conference and Exhibition
Session:	2DP.1.1
Pages:	699 - 702
ISBN:	3-936338-33-7
Paper DOI:	10.4229/28thEUPVSEC2013-2DP.1.1
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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Phosphorus-doped Czochralski-grown silicon (Cz-Si) is frequently used in the production of highefficiency silicon solar cells due to the absence of light-induced degradation, which is limiting the cell efficiency of solar cells made on boron-doped Cz-Si. However, new solar cell concepts may involve high-temperature process steps during cell processing, which can result in a significant reduction of the carrier lifetime in some n-type Cz-Si materials due to the formation of oxygen precipitates. In this case, the solar cell efficiency is then limited by the bulk material properties. The aim of this work is to investigate the influence of high-temperature processes, typically applied in solar cell processing, on the carrier lifetime of different n-type Cz-Si materials. It is shown that by applying a short high-temperature treatment before sample processing lifetime degradation can be inhibited. A conventional belt-firing furnace is shown to be suitable for this “tabula rasa” treatment.