A new design of non-volatile molecular switching device using [π⋯π] dimer

Area of Science:

• Molecular electronics
• Supramolecular chemistry
• Materials science

Background:

• Non-volatile resistive switching (NVRS) is crucial for molecular circuits.
• Current NVRS methods rely on mechanical deformation of molecular junctions, limiting scalability.
• A need exists for NVRS devices that maintain junction integrity during switching.

Purpose of the Study:

• To introduce a new molecular design for NVRS function.
• To achieve NVRS using a single, intact [π⋯π] supramolecular assembly.
• To demonstrate high ON/OFF ratios and device robustness.

Main Methods:

• Density-functional theory (DFT) studies to identify ON/OFF configurations.
• Climbing-image nudged elastic band (CI-NEB) calculations to confirm bistability.
• Quantum interference analysis for charge transport.

Main Results:

• A (phenylethynyl)bipyridine dimer as a single [π⋯π] supramolecular assembly was designed.
• Two stable configurations (ON/OFF states) of the dimer were identified.
• An ON/OFF ratio of 10⁴ was achieved due to opposite quantum interference effects.
• The device demonstrated robustness against lead offsets.

Conclusions:

• The proposed molecular design enables non-volatile resistive switching without junction deformation.
• The (phenylethynyl)bipyridine dimer offers a promising platform for future molecular electronic devices.
• Mechanical pulsing transverse to charge transport is an effective switching mechanism.