Nonvolatile Transition of Molecular Orbital Gating for Reconfigurable Molecular Ambipolar Transistor Switch

Abstract

Molecular electronics offers a promising avenue for ultimate device miniaturization, yet realizing versatile functionalities such as nonvolatile ambipolar switching in a robust solid-state transistor platform. Here, we report a reconfigurable molecular transistor switch achieved by vertically integrating an alkanethiol self-assembled monolayer (SAM) channel with monolayer graphene and a ferroelectric polymer gate. The ferroelectric polarization of the top gate allows for nonvolatile modulation of the Fermi level of the graphene relative to the molecular orbitals. This also enables reversible switching between hole- and electron-dominant conduction pathways within the same molecular channel, effectively creating an ambipolar switch. The switching conduction can be reconfigured on-demand by both gate and drain biases, as well as the molecular species. The device exhibits stable nonvolatile switching endurance over 100 cycles and retention for 103 s. Furthermore, leveraging the gate-tunable analog conductance states and nonvolatile characteristics, we present a proof-of-concept demonstration of synaptic plasticity, achieving ∼84.37% accuracy and ∼5.98 μJ of vector-matrix multiplication (VMM) energy per image in a Fashion-MNIST pattern recognition task. This work demonstrates a solid-state vertical molecular device for nonvolatile ambipolar transistors, supporting advanced reconfigurable in-memory computing and neuromorphic electronics utilizing molecular-scale channels.