Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Determination of impurity distributions in ingots of solar grade silicon by neutron activation analysis

: Karches, B.; Schön, J.; Gerstenberg, H.; Hampel, G.; Krenckel, P.; Plonka, C.; Ponsard, B.; Riepe, S.; Stieghorst, C.; Wiehl, N.


Radiochimica acta 105 (2017), No.7, pp.569-576
ISSN: 0033-8230
Journal Article
Fraunhofer ISE ()
Materialien - Solarzellen und Technologie; Photovoltaik; Silicium-Photovoltaik; feedstock; Kristallisation und Wafering; neutron activation analysis; transition metals; solar silicon; directional solidification

In a series of crystallization experiments, the directional solidification of silicon was investigated as a low cost path for the production of silicon wafers for solar cells. Instrumental neutron activation analysis was employed to measure the influence of different crystallization parameters on the distribution of 3d-metal impurities of the produced ingots. A theoretical model describing the involved diffusion and segregation processes during the solidification and cooling of the ingots could be verified by the experimental results. By successive etching of the samples after the irradiation, it could be shown that a layer of at least 60 μm of the samples has to be removed to get real bulk concentrations.