Improving the Texturization of n-Type c-Si Absorbers using Sodium Hypochlorite (NaOCl) as an Additional Component in the Standard Solution Containing a Mixture of IPA and KOH

The performance of solar cells is notably influenced by the etching process applied to silicon wafers, and surface texturing is a practical approach for reducing reflection on the front surface, hence enhancing overall efficiency. In this study, we explore the use of sodium hypochlorite (NaOCl) as an additive to isopropyl alcohol (IPA) in the alkaline etching process, aiming to reduce manufacturing costs. The etching process was conducted under consistent KOH content (6 wt %) with a duration of 20 minutes at a temperature of 80°C. Two sample sets were created, maintaining a steady IPA concentration at 1.5 vol.% in one set and 3.0 vol % in the other. Concurrently, NaOCl concentrations were systematically varied within the range of 0.05 to 0.25 vol % in increments of 0.05. The findings reveal that combining NaOCl and KOH results in a 13.08% reflectivity, with an optimal pyramid size of 6 µm, leading to the formation of pyramids with angles resembling theoretical values and ensuring a consistent growth pattern. Additionally, the diverse distribution of small, medium, and tall pyramids contributes to a reduction in reflectivity. Further investigation is recommended to explore the potential for reducing reflection in solar cell manufacturing.