Electrically Tunable Permanent Dipole Moment Switching in Fullerene-Encapsulated Water for Single-Molecule Electronics

A single-molecule switch operates as an electronic device capable of performing switching functions at molecular scale, offering incredibly small and efficient capabilities. This technology holds the potential for constructing highly integrated information processing systems, which could enhance advanced data storage and sophisticated logical manipulation. Herein, we systematically explored the electric field-dependent functional properties (potential energy surface, electronic structures, electron transport) of the encapsulated H2O by C60 fullerene (H2O@C60) using the first-principles calculation and non-equilibrium Green’s function. The orientation of the permanent electric dipole moment within the H2O@C60 structure is manipulated by rotating the encapsulated water molecules. This rotation, facilitated by an applied electric field, enables the creation of a bistable molecular switch—a system that can exist in one of two stable states (on or off).