Fig. 4From: Unraveling the Morphological Evolution and Etching Kinetics of Porous Silicon Nanowires During Metal-Assisted Chemical EtchingApparent etch rates observed after 30 min of etching in solutions composed of different HF–H2O2 molar ratios and H2O concentrations. a Etch rate of the Si nanostructures based on the resulting length. b, c Etch rate of the bulk Si with respect to the tip and base of the Si nanostructures, respectivelyBack to article page