Acid textures on polycrystalline and monocrystalline silicon wafers were made. Also monocrystalline wafers were different surface orientated (100) and (111). Texture mixture of HF:HNO3:CH3COOH had various volume ratio and led to different surface morphology examined using scanning electron microscopy SEM. Chemical etched surface should have a low reflectance in order to keep solar radiation inside the material and use it in the photovoltaic effect again. Holes should have rounded shape with several nm diameter.
Selected composition: 1HF:7HNO3:2diluent and 7HF:1HNO3:2diluent where diluents is CH3COOH or H2O. The time of texturing process was determined as 1 min and in some cases, following the literature, was elongated to 2 or 3 min. The next step is to implement on silicon wafers a typical cell technology involving diffusion from a POCl3 as a source, surface passivation by oxidation, anti-reflection layer deposition, ohmic contacts screen-printing, firing and electrical characterizing.