Relationship between the cell thickness and the optimum period of textured back reflectors in thin-film microcrystalline silicon solar cells

Abstract

Periodically textured back reflectors with hexagonal dimple arrays are applied to thin-film microcrystalline silicon (μc-Si:H) solar cells. When the textures have a moderate aspect ratio, the optimum period for obtaining a high short circuit current density (J_SC) is found to be equal to or slightly larger than the cell thickness. If the cell thickness exceeds the texture period, the cell surface tends to be flattened and texture-induced defects are generated, which constrain the improvement in J_SC. Based on these findings, we have fabricated optimized μc-Si:H cells achieving a high efficiency exceeding 10% and a J_SC of 30 mA/cm².