Antireflection subwavelength structures based on silicon nanowires arrays fabricated by metal-assisted chemical etching

摘要

In this paper, we have obtained a series of large-area and different diameters nanosphere lithography (NSL) to obtain the required silicon nanowires (SiNWs) arrays. The single-crystalline SiNWs have been presented by combining nanosphere lithography (NSL) and metal-assisted chemical etching (MACE). The period of SiNW arrays can be controlled by adjusting the original diameter of polystyrene nanosphere (PSs) and the etching time during the NSL process. The special SiNWs structure obtained can be demonstrated to be significant for improving the antireflection properties of silicon substrate. The results show that SiNW arrays with various parameters, such as diameter, distance and height can be obtained by controlling the key etching parameter during the MACE process, which are important to obtain the structures of different parameters to adapt an appropriate value to decrease the light scattering. For a wide wavelength range of 300-1200 nm, the reflectance is below 10% or less, which is due to an ultra-high surface area. Especially, the reflectance of antireflection structure (ARS) surface reduces below 1% over a wavelength range of 300-400 nm. Furthermore, the silicon nanowire (SiNW) arrays with highly efficient antireflection obtained by MACE exhibit different surface roughness from the bottom to the top part of SiNWs by high resolution images, which is benefit for further improving the ARS of SiNWs.