Investigations on the Impact of Wafer Grippers on Optical and Electrical Properties of Alkaline Textured and A-Si Passivated Surfaces

Automated wafer handling is inevitable during the production of crystalline silicon solar cells. Additional to the risk of wafer breakage, the influence of wafer handling devices on the optical and electrical properties of the solar cell proofs to be of great importance. This work investigates the influence of different wafer grippers on the optical properties of grown random pyramids as well as their impact on the quality of hydrogenated amorphous silicon (a-Si) passivation layers. The homogeneity of the random pyramids is characterized by examination of scanning electron microscopy (SEM) images and reflectance measurements. The influence of the wafer grippers on the electrical properties is investigated by calibrating quasi-steady-state photoconductance (QSSPC) measurements to photoluminescence (PL) images. We find that using grippers which distribute their exerted force on a larger area of the wafer surface provides better optical and electrical properties than using grippers with smaller, locally defined contact areas.