Green Etching Technologies: Reducing NO2Emissions while Enhancing Solar Cell Efficiency in Industrial Silicon Wafer Etching

Multi-crystalline Silicon (mc-Si) wafer’s surface texturing can increase solar cell’s conversion efficiency by lowering incident light reflectance. In this work, the optical characteristics of mc-Si wafers are enhanced through acid texturization. The major aim of this study is to reduce NO₂ emissions. Instead of HNO₃, we employed a combination of HF and H₂O₂, which are less hazardous chemical acids. This work highlights the benefits of using less hazardous and more affordable chemicals. Etching was carried out using a variety of chemical acids in different ratios. We prepared a 0.1 M solution of KMnO₄ and used in HF: H₂O₂:KMnO₄ in a 3:2:1 ratio. The outcomes of the 60-s etching process were compared with those of raw wafers. Optical microscopy, scanning electron microscope (SEM), UV–visible reflectance and lifetime measurements were used to examine the etched mc-Si wafer. The presence of H₂O₂ reduces the pollution and enhances the utilization of incident photons in solar cell applications.

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