O. Breitenstein

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By evaluating dark lock-in thermography images taken at one reverse and three forward biases, images of all two-diode-parameters J<inf>01</inf>, J<inf>02</inf>, n<inf>2</inf> (ideality factor of J<inf>02</inf>), and G<inf>p</inf> (the parallel ohmic conductivity) are obtained. A local series resistance is explicitly considered and may be provided as a(More)
We present a comprehensive overview over infrared imaging techniques for (electrical) silicon solar cell characterization. Recent method development in local series resistance imaging is reviewed in more detail and new results in local breakdown investigations on multicrystalline (mc) silicon solar cells are reported. We observe local junction breakdown(More)
means of recombination statistics beyond the Shockley-Read-Hall approximation Silke Steingrube, Otwin Breitenstein, Klaus Ramspeck, Stefan Glunz, Andreas Schenk, and Pietro P. Altermatt Department Solar Energy, Institute Solid-State Physics, Leibniz University of Hannover, Appelstr. 2, 30167 Hannover, Germany Max-Planck-Institute of Microstructure Physics,(More)
Electroluminescence (EL) and photoluminescence (PL) imaging have recently been demonstrated to be fast experimental techniques that allow measurement of the spatial distribution of the diffusion length in silicon solar cells and of the minority carrier lifetime in large area silicon wafers [1, 2]. A practical advantage of these techniques is that data(More)
In recent years, a detrimental degradation mechanism of solar cells in large photovoltaic fields called potential-induced degradation (PID) has been intensively investigated and discussed. Here, the module efficiency is decreasing down to a fractional part of their original efficiency. In this study, we introduce a PID test at a solar-cell level and for(More)
Shunting Problems Due to Sub-Micron Pinholes in Evaporated Solid-Phase Crystallised Poly-Si Thin-Film Solar Cells on Glass O. Kunz1*,y, J. Wong, J. Janssens, J. Bauer, O. Breitenstein and A.G. Aberle Photovoltaics Centre of Excellence, The University of New South Wales, Sydney, NSW 2052, Australia Max Planck Institute of Microstructure Physics, Weinberg 2,(More)
We have identified at least five different local breakdown mechanisms according to the temperature coefficient (TC) and slope of their characteristics and electroluminescence (EL) under reverse bias. These are (1) early pre-breakdown (strongly negative TC, low slope), (2) edge breakdown (positive TC, low slope, no EL), (3) weak defect-induced breakdown(More)
The purpose of this paper is a detailed comparison of selected luminescence and lock-in thermography (LIT) results on one exemplary sample and the drawing of corresponding conclusions. Our focus is on solar cells, but some investigations on wafers will be discussed as well. The comparison will help to decide which characterization tools are needed to solve(More)
Lomer dislocations at small-angle grain boundaries in multicrystalline silicon solar cells have been identified as responsible for the dominating inherent dark current losses. Resulting efficiency losses have been quantified by dark lock-in thermography to be locally up to several percent absolute, reducing the maximum power of the cells. By electron beam(More)