Fig. 4. SEM images of Ag nanostructures deposited onto Si substrates at a current density of 2 mA cm⁻² for 12 min in an ethanol-based electrolyte containing 0.1 mM AgNO₃ and 0.14 M HF with different additives: (a) 1 mM L-AA, (b) 1 mM PVP and (c) 1 mM L-AA and 1 mM PVP.