2D Porous Organic Polymer Sheet/Graphene Hybrid for Efficient UV‐Sensitive Detections and Self‐Restoring Flexible Synaptic Devices With 10,000 s Ultralong Memory

Abstract Flexible UV‐sensitive photodetectors and optoelectronic synapses are highly desired in numerous sensing areas and neuromorphic computations. Herein, the large‐size, flat, and continuous sheet of polyamic acid (PAA), a two‐dimensional (2D) porous organic polymer (POP), was synthesized at the liquid/liquid interface. Combining with graphene (G), the hybrids demonstrate efficient UV‐selective photodetection. On the soft substrate of polyethylene glycol terephthalate (PET), the UV‐selective detecting ability is retained even under 90° bending and after 20,000 bending cycles, indicating the remarkable flexibilities. And our PAA/G/PET devices exhibit self‐healing capability via a simple thermal annealing at 45°C. The remarkable flexibilities can be attributed to the high mechanical strength of 2D covalent‐bonded backbones of PAA and G, the adaptive porous connections, and reversible broken/reformation of the large number of hydrogen bonds in PAA. Furthermore, the PAA/G/PET devices can mimic the functions of biosynapse very well, including paired‐pulse facilitation, short‐term plasticity (STP) and long‐term plasticity (LTP), transition of STP to LTP, spike time, number, and intensity‐dependent plasticity. With this optoelectronic synapse, the human brain‐like process and wireless communications are realized. The memory time can achieve 10,000 s after 45 s learning. And the synaptic functions persist at the bending angle of 90°. The results in this work provide valuable support for developing flexible wavelength‐selective photodetectors and artificial synapses with 2D POPs and their hybrid films.