Recommendations on the preparation of silicon solar cell samples for defect etching

Research on the structural defects of silicon such as grain boundaries and dislocations, their spatial distribution and how they impact the resulting solar cell performance often proceed by polishing the sample, etching to reveal the dislocations and grain boundaries, and then scanning the surface to image the defects and record their corresponding positions. While a lot of work has been devoted to developing appropriate etches and how to correlate the etch pits to cell performance, materials pertaining to preparation of samples for defect etching, which is a crucial step to ensure successful imaging and analysis, are limited. This work describes a method of polishing multicrystalline silicon solar cell samples in preparation for defect etching. The method described herein: • Utilizes both mechanical and chemical mechanical polishing. • Can be applied to both fabricated silicon solar cells and as-cut wafers.