Evaluation of Sawing Damage for Thin Flexible Silicon Solar Cells

In this study, we evaluated sawing damage of thin silicon wafers. Ultra-thin silicon wafers with great advantages of bendability and lightweight are suitable for needs such as to realize PV-powered vehicles. For thin wafers, it is important to realize high precision slicing to prevent breakage. We evaluated the distribution of sawing damage and crystallinity in order to clarify the cause of wafer breakage and establish low damage slice conditions. We confirmed phase transformation of silicon and crystalline defects on wire exit side on the conventional slicing surface, while the advanced slicing surface shows almost only single-crystalline Si phase.