Fig. 6From: Unraveling the Morphological Evolution and Etching Kinetics of Porous Silicon Nanowires During Metal-Assisted Chemical EtchingEvolution of SiNW length with time for different H2O concentrations at a fixed HF–H2O2 molar ratio of 0.95. a Effect of etch time on SiNW length. b, c SEM images of SiNWs after etching for 1 h in a solution composed of HF–H2O2 molar ratios of 0.95 and H2O concentrations of 46 and 50 M, respectively. d, e Etched bulk Si thickness with respect to the tip and base of the SiNWs over timeBack to article page