Opening Extra Transport Channels by Atomically Precise Doping in Gold Nanoclusters with Electronic Structure Modulation

In the design of implantable electrodes, the choice of electrode materials and associated interface engineering directly determines the charge transport behavior. By focusing on silver, the best conductive metal, as the electrode, one can explore the design of the interface with better biocompatibility and conductivity. In recent years, atomically precise gold nanoclusters have been proposed as electrode interface modifiers, providing new possibilities for controlling the interfacial electronic structure and charge transport. Herein, the Ag-X-Ag (X = Au₂₅CH₃, Au₂₄CdCH₃, Au₂₄CuCH₃) model systems are constructed to study charge transport at the nanocluster-electrode interface with density functional theory-nonequilibrium Green's function calculation and neuroevolution potential-based molecular dynamics simulation. The structures of gold nanoclusters at the interface exhibit enhanced charge transport properties after relaxation, which is attributed to dopant-induced geometric rearrangement and enhanced interfacial coupling effects. The enhancement of the interfacial coupling effects is most prominent when the dopant is positioned near the left electrode (configuration 2). Cd doping yields the greatest enhancement, characterized by stronger resonant transmission, a higher density of states near the Fermi level, increased current, and reduced impedance. Furthermore, the transport properties show weak temperature dependence, which reflects the synergistic interaction between the metallic Ag electrode and the semiconducting-like nanocluster. Atomically precise doping in gold nanoclusters offers an effective approach to enhancing interfacial transport efficiency and provides a generalizable strategy for advanced electrode design in next-generation, high-performance transport devices.