Wet chemical etching silicon wafer with low-reflection and super-hydrophobicity

Successful etching silicon wafer for solar cells has been already prepared. In this work, wet chemical etching process at room temperature was introduced to fabricate large-area growth of Si nanowire (SiNW) arrays. The process was carried out on p-type (100) silicon wafer in aqueous HF+AgNO₃ etching solution at room temperature. The wafer surface consisting of SiNW arrays shows the characteristics of low-reflection as low as less than 5% in the 450-790 nm wavelength range. The surface also exhibits super hydrophobicity with a high water contact angle up to 150°. Si wafers with large-area SiNW arrays on the surfaces displaying properties of low-reflection and super-hydrophobicity will have potential applications for fabricating high-efficiency and self-cleaning silicon solar cells.