Design,Synthesis And Memristive Properties Of Porphyrin-Based Polymers

With the great development of new generation information technologies such as the Internet of Things,cloud computing and big data,there is an ever-increasing need for a higher quality of complex data processing.According to the latest"Semiconductor International Technology Roadmap",the strategy of integrating more components per unit area to improve device performance by reducing the device size will reach the bottleneck in 2022.Neuromorphic calculation is a brain-like calculation that is expected to break through the von Neumann framework.At present,the development of new synaptic electronic components with computing and storage capabilities is the key to the formation of neuromorphic systems.The function of memristive synaptic synapses provides a feasible solution for realizing neuromorphic calculations.Organic semiconductors have many advantages such as low cost,molecular structure design,large-area flexible manufacturing and simple preparation process,and become one of the strong candidates for memristive device materials.However,organic small molecule/polymer memristors are often accompanied by problems such as high operating voltage and obvious fluctuations parameters due to defects and complex condensed states.In response to the above problems,our research group studied a class of oxygen ion-migrating memristors based on porphyrin small molecules and found that the device possess stable multi-functional synaptic simulation performance.In this thesis,a class of porphyrin polymers was designed and synthesized and applied to memristors.The synaptic function simulation was deeply studied.?1?The porphyrin was prepared by Lindsey reaction,and the 2Br2ORTPP porphyrin monomer was synthesized.The synthesis route was improved and optimized.The principle of reversible reaction of porphyrin was explained by structure identification and reaction path analysis.PH2TPP-SFX and PZnTPP-SFX were obtained by suzuki polymerization between 2Br2ORTPP or2Br2ORTPPZn monomers and SFX2B.The coordinated-zinc polymer was also converted through metal coordination reaction with PH2TPP-SFX.The successful preparation of porphyrin polymers also provides a material basis for the preparation of memristors.?2?Porphyrin copolymer-based memristor was prepared and the synaptic function simulation were carried out.The structure of ITO/PZnTPP-SFX/Al₂O₃-x/Al device was prepared by spin-coating method.The device performances of PH2TPP-SFX and PZnTPP-SFX were investigated to detail different memristive properties.To further explore the mechanism of such memristors,two devices with structures ITO/PZnTPP-SFX/Al and ITO/Al₂O_3-x/Al were designed.Experiments showed that both devices exhibit linear resistance characteristics,indicating that both PZnTPP-SFX and Al₂O_3-x must cooperate at the same time,further verifying the PZnTPP-SFX-assisted Al₂O_3-x oxygen ion source transmission.The device simultaneously simulates frequency-dependent plasticity,amplitude-dependent plasticity,and learning-forget-re-learning behaviors.?3?Based on the optimization strategy of porphyrin synthesis in chapter 2,dibromotetraphenylporphyrin with hexalkoxy chain was synthesized in this chapter.The porphyrin monomer coordinates the zinc ion could form a zinc porphyrin polymerizable monomer.The polymer PZnTPP was synthesized by Yamamoto polymerization method.By controlling the concentration of spin-coating solution,different thicknesses of the PZnTPP active layer were prepared.Comparing the experimental results,the ITO/PZnTPP/?72 nm?Al₂O_3-x/Al device exhibited a smooth IV curve,strong anti-pulse saturation,and good repeatability.This memristor exhibits stable memristive properties.The synaptic function simulations were further investigated,such as pulse stimulation,"Matthew effect"and learning-forget behaviors.The PZnTPP device has improved resistance to saturation and high voltage compared to PZnTPP-SFX devices.