Tunable electronic and chemical properties of Fe@Si_n clusters: Potential in nanoelectronics and sensing, a DFT-based study

We present a comprehensive Density Functional Theory (DFT) study on the structural, electronic, and chemical properties of Fe-doped silicon clusters (Fe@Si_n, n = 1–10) to understand their stability and potential applications in nanoelectronics and catalysis. The binding energy (BE) analysis reveals that Fe@Si₇, and Fe@Si₈ exhibits the high stability, attributed to strong Fe-Si interactions. Additionally, the second-order energy difference (Δ²E) highlights Fe@Si₄, Fe@Si₇ indicating enhanced nature. The HOMO-LUMO gap trends suggest a transition from semiconducting to metallic behavior which further confirmed through density of states analysis. Electron affinity (EA) and ionization potential (IP) calculations indicate that Fe@Si₆ and Fe@Si₇ possess strong charge storage and redox activity, making them promising candidates for catalysis and energy storage applications. Furthermore, the chemical potential (μ) and hardness (η) trends confirm Fe@Si₈ as the most stable cluster, whereas Fe@Si₇ is highly reactive and may be suitable for chemical sensing or catalytic applications. These findings provide crucial insights into the tunability of Fe@Si_n clusters, paving the way for their potential use in nanoelectronic devices, catalysis, and energy storage, and sensing applications.