Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 55: Photovoltaics: Silicon-based Systems II
HL 55.5: Talk
Wednesday, March 28, 2012, 12:15–12:30, ER 270
Classification of different types of precipitates grown in block-cast multicrystalline solar silicon — •Susanne Richter1, Martina Werner1, Sina Swatek1, Benjamin März2, and Christian Hagendorf1 — 1Fraunhofer-Center für Silizium-Photovoltaik CSP, Walter-Hülse-Str. 1, 06120 Halle (Saale) — 2Fraunhofer-Intstitut für Werkstoffmechanik IWM, Walter-Hülse-Str. 1, 06120 Halle (Saale)
Precipitates in multicrystalline silicon (mc-Si) for wafer-based solar cell production are of great importance for the efficiency and production yield in the photovoltaic industry. In particular, it has been shown that during the crystallization of mc-Si ingots the accumulation of C and N in the Si melt results in the development of precipitates like SiC and Si3N4 in various morphologies. We present here a study on the morphological structure and the elemental composition of different types of precipitates. In particular, intermixture types occasionally occurring during the growth of mc-Si ingots in VGF crystallizers were investigated. Results from different methods for microstructural, morphologic and chemical analyses including IR microscopy, ToF-SIMS, FIB target preparation for TEM combined with nanospot-EDS and SAED are shown. A more detailed classification with the help of the investigated material properties is proposed.