Glen Bennett Cook

First Solar Cell Results on Novel Direct-Cast Silicon Wafers

Today’s costs of silicon wafer material of a photovoltaic module are around 30-40% of its total production costs including feedstock, ingot casting and wafering. Therefore, there is a substantial interest in the development of a kerf-loss free and thus cost-saving silicon wafer production. One method amongst various technologies for direct wafer production is the Direct-Cast Silicon (DCS) process. In this wafer casting process, molten silicon is directly crystallized on a re-usable substrate. The exploration of the solar cell efficiency potential and the characterization of DCS wafer material are of immanent relevance for future development of the DCS technology. A high efficiency solar cell process, developed for defect-rich multicrystalline silicon material at the University of Konstanz, was applied on DCS wafers. IV measurements, Light Beam Induced Current (LBIC) and electroluminescence (EL) were performed. The goal was to gain insight into the material quality and material properties, and to provide feedback for wafer production. Thereby, with 16.0%, the highest solar cell efficiency for this material could be obtained so far.