Metal-Assisted Silicon Chemical Etching Using Self Assembled Sacrificial Nickel Nanoparticles Template for Anti-Reflection Layers in Photovoltaic and Light-Trapping Devices

Thin film de-wetting is a simple patterning approach that provides a straight forward method for fabricating silicon structures using metal-assisted chemical etching (MacEtch). Currently, this has been mainly demonstrated with gold (Au) or silver (Ag) catalyst for MacEtch and to accomplish this, an extra Au or Ag nanoparticles lift-off step is required. The uncertain success with the lift-off process is potentially a major hindrance to achieve low-cost, large-scale and uniform Si nanostructures. In this work, we report on the use of nickel (Ni) as an alternative sacrificial metal for the de-wetting process. The de-wetting phenomenon of Ni on silicon dioxide is investigated to show that controllable sizes and density are achievable for this material system. A physical model to describe the relationship among Ni film thickness, particle interspacing and density is proposed. Using the Ni nanoparticles as a starting mask template, an improved approach for the large scale fabrication of silicon nanowires witho...