Köstner, S.
,
H. Cypionka
,
V. Schoonderwoert
,
J. Bauer
,
J.-M. Wagner
,
and O. Breitenstein
3D subsurface imaging of precipitates inside block-cast silicon.
SiC filaments are known to cause severe ohmic shunts in mc-Si solar cells. However, not all of them contribute to ohmic shunting. In order to obtain information on how the SiC filaments are embedded inside the bulk material, we demonstrate a novel method which reveals the 3d geometry of the embedded structures at high resolution (below 1 micron). This method is based on an improved algorithm for extended depth-of-focus imaging, evaluating a stack of about 50 IR microscopy images by considering their local contrast. For comparison, a commercial deconvolution algorithm with a depth-dependent point-spread function is used. The resulting 3d images permit the electrical characterization of embedded SiC filaments, knowing exactly their geometry. Further, new insights on the growing mechanisms of SiC filaments can be expected.
Proceedings 24th European Photovoltaic Solar Energy Conference and Exhibition (24th EU PVSEC)
,
p 2270-2274
WIP,
Munich, Germany
(2009)
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