Influence of Experimental Conditions on the Antireflection Properties of Silicon Nanowires Fabricated by Metal-Assisted Etching Method

In this paper, silicon nanowire (SiNW) arrays with the different structural parameters were prepared by the electroless metal assisted chemical etching method through changing the AgNO3 concentration in the etching solution and etching time. For the concentration of AgNO3 of 0.04M and the etching time of 8 min, the SiNW arrays with minimum reflectance were obtained. The average reflectivity of the SiNW arrays could be as low as 2.0% for the wavelength in the range of 300-1100nm. The measurements of reflectivity and morphology of SiNW arrays indicated that the reflectivity of SiNW arrays were not only sensitive to the length of the nanowires, but also dependent on the diameter, distribution period and the filling ratio of diameter to distribution period of the nanowires. When the filling ratio is around 0.45, the distribution period of the SiNW arrays is 110 ± 10nm, diameter is smaller and length is longer, the reflectivity will be lower.