Optical and compositional characterisation of stain-etched porous silicon subjected to anodic oxidation and thermal treatments

In this work, we study optical and compositional properties of stain-etched porous silicon (PS) passivated by means of anodic oxidation or thermal treatments in a N2 atmosphere. We search a passivation method that allows us to stabilise the surface properties of this material and to make it attractive to its implementation in a low-cost silicon-based solar cell fabrication process. We observe that the thermal treatment maintains the reflectance coefficient at very low values, and the anodic oxidation generates surfaces with a more homogeneous oxide composition than the thermal treatment. These results are appropriate with the requirements for future solar cells that can use these passivated porous layers as antireflection coatings.