Nanoarchitectonics for Regulating Molecular Conductance by Multi-Channel Structure

Molecular electronics represents the cutting-edge and interdisciplinary effort on the future miniaturization of electronic circuits. Benefiting from synthetic chemistry and theoretical insights, molecular circuit studies have promoted devices with increasingly complicated structures. Especially, the evolution of conductive backbones from simple chain-shaped single-channel configurations to complex multi-channel architectures marks a pivotal progression. A comprehensive understanding of charge transport and conductance properties in multi-channel molecular devices is crucial for further developing molecular circuits. In this review, we provide an overview of conductance properties, categorizing the effect on conductance into enhancement or suppression. The underlying mechanisms of conductance modulation are discussed. While conductance enhancement is attributed to factors of the quantum-interference-based superposition law, the charge-induced self-gating effect, and the facilitation of additional conductive channels through space-mediated transport; while the conductance suppression originates from the destructive quantum interference in saturated conductive channels and the "electron selective transport" feature within multi-channel structures where channels converge at a phenyl group.