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

Abstract 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 the brain-like processing behavior. However, due to the poor long-term operating stability, low intrinsic conductivity, and inferior charge transfer ability, their electronic synaptic applications are largely restricted. Herein, we controllably synthesize 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 media 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 electrode and PI as substrate is fabricated, presenting gradient conductance modulation under both continuous electrical scanning and pulse algorithm, closely simulating the biological synaptic behaviors. More importantly, such 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.