Semiconductor electrodes offer powerful routes to engineer electrochemical function, yet predicting surface confined charge transfer remains challenging because crystallography and doping reshape interfacial structure, band bending, and potential distribution. Zhong et al. mapped these coupled effects reported recently by Frontiers of Materials Science, using ferrocene (Fc) monolayers grafted onto hydrogen-terminated p- and n-type Si(100), Si(110), and Si(111). Successful functionalization was confirmed by X-ray photoelectron spectroscopy and cyclic voltammetry. The Fc surface coverage (Γ) is strongly facet dependent and, in particular, doping reverses the facet selectivity. In contrast, the Fc/Fc⁺ mid-point potential shows a consistent orientation hierarchy for both dopings with an additional ~20–40 mV positive shift on n-type relative to p-type, indicating robust redox energetics with doping-controlled offsets. Peak widths exceed the ideal surface-confined limit and, together with impedance responses, point to non-ideal behavior dominated by interfacial electrostatics rather than ohmic artifacts. This facet-by-doping map clarifies how the silicon surface structure and electronic boundary conditions partition their influence across the monolayer formation and redox energetics, providing guidance for silicon-based molecular electrochemical interfaces in sensing and molecular electronics.
DOI: 10.1007/s11706-026-0764-1