Accurate controlled deposition of silver nanoparticles on porous silicon by drifted ions in electrolytic solution

In this study, a low-cost, simple, single-step low-voltage operation and a well-controlled method for deposition of uniformed and unique size distributions of silver nanoparticles (AgNPs) on the porous silicon (PS) layer were achieved via controlling the drift velocity of electrons in an aqueous solution of AgNO₃. The laser diode of 530 nm and 60 mW/cm² laser wavelength and illumination power density was employed to prepare PS layer by a laser-assisted etching process. The PS layer was incorporated on the platinum disk cathode electrode, and a stainless steel plate as an anode was employed. Low applied operating voltage of about 3V DC at different drift currents of 10, 20, 30 and 40 mA for 2 min was applied to sustain the drift motion of Ag²⁺. Structural properties of AgNPs layer were examined via the field emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) pattern. These measurements exposed that AgNPs were adjusted by controlling the drift current, and a uniform AgNPs with specific unique sizes were obtained. Grain size, specific surface area and nucleation sites of metallic AgNPs were intensely influenced by the drift current.