All-solution-processable hydrogen-bonded organic framework artificial synapse for neuromorphic application

Organic materials that exhibit gradient conductance plasticity are currently regarded as promising candidates to play the key role of bionic synapses in flexible neuromorphic circuits, mimicking brain-like processing behavior. However, owing to their poor long-term operating stability, low intrinsic conductivity, and inferior charge transfer ability, their electronic synaptic applications are largely restricted. Herein, we controllably synthesized a two-dimensional (2D) flake-like hydrogen-bonded organic framework composed of meso-tetra(carboxyphenyl) porphyrin monomers (TCPP-HOF), which serves as a reliable synaptic medium with high material stability and enhanced charge-carrier transportation. An all-solution-processed 10×10 2D MXene/TCPP-HOF/MXene/polyimine (PI) heterostructured flexible device array using MXene as the electrode and PI as the substrate is fabricated, presenting gradient conductance modulation under both continuous electrical scanning and pulse algorithms, closely simulating biological synaptic behaviors. More importantly, such a metal-electrode-free device is easily degradable, giving the possibility of recyclable transient electronics and information security. This work sets a precedent for the development of highly viable HOF-manipulated artificial synaptic mimicry for low-cost, easily processed, and highly efficient neuromorphic applications.