Application of infrared birefringence imaging for measuring residual stress in multicrystalline, quasi-mono, dendritic web, and string ribbon silicon for solar cells

Abstract

One of the parameters with highest impact on photovoltaic module cost is manufacturing yield during solar cell production. Yield is, to a great extent, directly affected by the crystallization technique used to grow the substrate wafers due to its role in generating residual stresses that can lead to fracture upon wafer processing and handling. This thesis explores the nature, impact, and a method for quantifying residual stresses in silicon wafers used for solar cells. The combination of an infrared birefringence imaging technique along with a sectioning method is proposed as an approach to spatially resolve and decouple the in-plane residual stress components on four wafers originating from different growth methods. The suitability of this technique is verified, and recommendations for future expansion of this work are presented.