Construction of functional grain boundary clusters for casting large-size and high-quality monocrystalline silicon ingots

Abstract

This study evaluates the impact of functional grain boundary cluster (FGBC) technology on the quality and performance of cast monocrystalline silicon (mono-Si) ingots and solar cells. The FGBC technique effectively creates a barrier between multicrystalline silicon (mc-Si) and mono-Si regions, significantly preventing mc-Si overgrowth and enhancing the crystal quality of the ingot. Infrared imaging and defect analysis reveal that the proportion of mono-Si ingots grown with FGBC increases significantly to 95%, compared to 60% in ingots without FGBC. Additionally, minority carrier lifetime distributions indicate that the FGBC significantly reduces crystal defects in the edge regions of the ingot, maintaining the structural integrity of the grain boundaries. Solar cell performance tests shown an absolute cell efficiency increase of approximately 0.3% for wafers grown with FGBC, significantly reducing the efficiency gap between edge and center wafers. Overall, the application of FGBC in cast mono-Si production not only improves the yield of mono-Si ingots but also enhances the efficiency distribution of solar cells, providing a reliable solution for the large-scale application of cast mono-Si in the PV industry.