Figure 4
From: Controllable synthesis of branched ZnO/Si nanowire arrays with hierarchical structure
SEM images of Si nanowire arrays prepared at room temperature in different solution. (a) Substrate directly immersed in HF/AgNO3 (5.25/0.02 M) aqueous solution for 20 min. (b) Substrate immersed in HF/AgNO3 (4.6/0.01 M) aqueous solution for 60 s and subsequently transferred into HF/Fe(NO3)3 (4.6/0.135 M) aqueous solution for 20 min. (c) Substrate immersed in HF/AgNO3 (4.8/0.01 M) aqueous solution for 10 s and subsequently transferred into HF/H2O2 (4.6/0.4 M) aqueous solution for 15 min.