Single-Molecule Magnet Bridging Along Exposed Sidewalls of Metal–Insulator–Semiconductor Diodes for Molecular Transport Studies

Single-Molecule Magnets (SMMs) are promising for molecular spintronics owing to their quantum properties; however, reproducible integration into devices has remained challenging due to limitations of break-junction and gold-based systems. This study introduces a scalable NiFe/AlOx/p-Si Metal–Insulator–Semiconductor (MIS) platform that enables reliable sidewall bridging of lipoic acid–functionalized Mn₆ SMMs through disulfide linkages. Despite fabrication-related variability in pristine MIS junctions, molecular integration produced convergent tunneling characteristics across multiple devices, as confirmed by standard deviation analysis, thus addressing reproducibility issues common in molecular systems. Kelvin Probe Force Microscopy (KPFM) revealed an approximately 0.4 V increase in NiFe surface potential following SMM attachment, providing electrode-level evidence of molecular influence. Conceptual modeling suggests two cooperative mechanisms: (i) orbital-assisted tunneling that reduces effective barrier height and enhances interfacial density of states, and (ii) charge redistribution at the NiFe/SMM interface, resulting in band flattening and surface potential rise. These mechanisms collectively account for the reproducibility and interfacial modifications observed experimentally. Although spin-selective transport awaits direct confirmation, the demonstrated reproducibility and scalability establish this MIS–SMM architecture as a robust testbed for molecular integration and a viable route toward spintronic device applications. The study provides immediate relevance for molecular electronics and defines a foundation for advanced investigations using complementary low-temperature and magnetic characterization methods such as SQUID magnetometry, EPR spectroscopy, and magneto-transport.