Influence of inclusion on nucleation of silicon casting for photovoltaic (PV) application

The photovoltaic (PV) industry has grown rapidly in recent years. The predominant PV material, multicrystalline silicon (mc-Si), is manufactured by relatively low-cost casting methods, especially directional solidification. One factor affecting the quality of cast silicon and the resultant mc-Si solar cells is Si3N4 and SiC precipitates and inclusions. These inclusions cause crystal defects, distorted grain structure, decreased wafer yield and quality and even electrical shunts. A Computational Fluid Dynamic (CFD) Simulation tool has been applied to simulate temperatures and flow fields during growth and how they will affect the grain structure under the influence of inclusions. The Cellular Automata Finite Element (CAFE) modeling technique is used to simulate silicon grain growth.