LAUSR

Abstract Silicon porosification by silver assisted chemical etching (Ag-ACE) for a short range of H 2 O 2 concentration is reported. We experimentally show that porous silicon (PSi) is obtained for 1% H 2 O 2 , whereas silicon nanowires (SiNWs) appeared by simply tuning the concentration of H 2 O 2 to relatively high concentrations up to 8%. The morphological aspects are claimed by scanning electron microscopy proving that the kinetics of SiNWs formation display nonlinear relationships versus H 2 O 2 concentration and etching time. A semi-qualitative electrochemical etching model based on local anodic, Ic, and cathodic, Ia, currents is proposed to explain the different morphological changes, and to unveil the formation pathways of both PS and SiNWs. More importantly, an efficient antireflective character for silicon solar cell (reflectance close to 2%) is realized at 8% H 2 O 2 . In addition, the luminescence of the prepared Si-nanostructures is claimed by photoluminescence which exhibit a large enhancement of the intensity and a blue shift for narrow and deep SiNWs.