Formation of Nano-Textured Silicon Surface Layer (or Nanowires) by Silver Ion-Assisted Etching

To obtain an ultralow surface reflectance and reach broadband antireflection effects,in this paper, silicon nanowires (SiNWs) layer has been fabricated by low-cost and easy-made silver-assisted etching techniques.The morphologies, reflectance and surface recombination of the samples were separately characterized. The ultralow reflectance below 3% from 300 to 800 nm under normal incidence has been realized in the case of ~ 1 μm long SiNWs whose geometry structures approximate to multi-layer gratings stack and the refractive index gradually increases from the top to the bottom of substrate. However, surface recombination of SiNWs deteriorates due to numerous dangling bonds and residual silver. Therefore, a trade-off between antireflection effect and recombination loss is the key to the electronic device.