Surface roughness characterization of annealed polycrystalline silicon solar wafers using a laser speckle imaging (LSI) technique

Abstract

Surface roughness variation of optically rough polycrystalline silicon solar wafer by annealing at different temperatures is presented. Laser speckle images produced by annealed polycrystalline silicon solar wafer wafers are recorded and converted into binary images. The binary speckle images are characterized by fractal box counting method. The fractal dimensions decreases, while annealing temperature increases; therefore, the polycrystalline silicon solar wafer roughness decreases while annealing temperature increases.