Angelika Hahnel

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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)
During crystallization of multicrystalline silicon, carbon-rich liquid-solid phase-boundary layers appear, resulting in precipitation of n-type conductive Si-C-N filaments.We present an in-depth structural analysis of distinct types of filaments to support modeling of their growth. Phase-contrast microtomography down to the submicron level is used to study(More)
This study examined the relationships between gross chemical composition and ultrasonographic characteristics of the ram testes. Ten testes from sexually mature Karakul rams were scanned ex situ with an 8-MHz linear-array transducer, in a transverse and longitudinal plane. All ultrasonograms were saved as digital images and subjected to computerized(More)
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