Antireflective nanostructures fabricated by reactive ion etching method on pyramid-structured silicon surface

► A low reflectance of 4.72% was obtained by etching the pyramid-structured silicon wafers in a RIE system. ► The whole etching process was at room temperature and without any negative voltage pulses. ► Samples etched with FO2 lower than 6 sccm can't get low reflective silicon structure. ► Too big etching power of 225 W would make the nanostructures too sparse to obtain a low reflectance.