A novel square silicon nanohole structure: Fabrication and antireflective property

In this paper, a novel square silicon nanoholes light-trapping structure of solar cells was prepared by improved electroless etching method, which is different from the irregular nanoholes and round nanoholes reported earlier by corrosion method in the silicon substrate. We analyzed the formation process of this structure and found that the concentration of nitric acid silver in the solution can determine the formation of the square nanoholes. Moreover, we demonstrated that the longer etching time, the deeper the silicon nanoholes. This square silicon nanohole arrays could suppress the reflection drastically over a wide spectral band width ranging from 300 to 1100 nm.