Growth mechanism of silver dendrites on porous silicon by single-step electrochemical synthesis method

Silver micro/nanostructures are often used to enhance surface-enhanced Raman scattering (SERS) due their hotspot effect. In this paper, a single-step electrochemical etching method was used to prepare silver dendrites with stems, branches and leaf morphology on porous silicon. A detailed analysis of the evolution and growth mechanism of the silver dendrites on the porous silicon was conducted, based on diffusion-limited aggregation, the anisotropy associated with the solid–liquid interface energy, and taking into account different growth rates. The SERS efficiency of the analyte molecule Rhodamine 6G was evaluated, achieving a low detection limit of up to 10 –11 M concentration. The linear relationship between Rhodamine 6G concentration and Raman peak intensity is good within the concentration range of 10 –4 –10 –11 M, and the linear fitting equation is y = − 4479.4 x + 41,952.9 ( R 2 = 0.9815). Therefore, the results indicate that different silver dendrites can be prepared by controlling the time, which is beneficial for the design of silver dendrite-based composites with high SERS performance.