Research On Organic Field Effect Transistor Non-volatile Memory Based On Molecular Floating Gat

In recent years,with the flourishing of various emerging applications suitable for wearable and skin repair electronic devices,more demands have been placed on organic memory with mechanical flexibility.The floating gate non-volatile memory is the main research object of this paper.The main research content is to optimize the core system of memory and improve the related performance parameters of memory.The design of device structure,the selection of materials,interface control,preparation technology,memory performance and physical mechanism are studied.On the one hand,the scientific research results update the research ideas and methods in improving the performance of transistor memory.On the other hand,it provides key data support and strategic ideas for the application and development of new field effect transistor memory technology.The main research directions and achievements are as follows:1、The solution mixing method was adopted to build polymer semiconductor poly（9,9-dioctylflfluorene-co-benzothiadiazole）（F8BT）nanoparticles（NPs）,which were mixed with poly（methyl methacrylate）（PMMA）in a solution to prepare an integrated floating-gate/tunneling layer.On this basis,flexible floating-gate based organic field-effect transistor non-volatile memories（F-OFET-NVMs）were prepared.The intrinsic correlations of the microstructures in the integrated floating-gate/tunneling layer of the memory devices with the device performance were explored.Moreover,correlations of the charge injection and discharge,physical mechanism of memory,and charge trapping capacity of the floating-gate/tunneling layer with different F8BT/PMMA mass ratios with the key parameters of memory devices were investigated.Relevant results indicate that the memory devices are able to well trap charges inside the F8BT NPs during operation at a programming voltage of+40 V,an erasing voltage of-40 V,and a pulse width of 1 s.The floating gate acquires the injected and trapped bipolar charges（electrons and holes）.The optimized high-performance memory device is found to have an average memory window of 9.5 V,remain stable for more than three years,and have reliable stability in more than100 erase/write cycles.Furthermore,the memory device also exhibits outstanding durability under mechanical bending and still has high storage stability after 6,000 times of bending with a bending radius of 3 mm.The research results powerfully promote the research progress of applying semiconductor polymers to memory devices.2、Organic field-effect transistors（OFETs）with low-voltage-operating high-stability are regarded as one of the key components of future electronics.However,it remains a challenge to enhance bias–stress stability,mechanical durability and environmental adaptability while reducing the operating voltage of the flexible OFETs.In this study,a new strategy of introducing high-dipole-moment groups into polymer side chains to enhance the intensity of polarization was proposed.This strategy can redirect cyclic carbonate side chains of high-dipole groups under the action of electric fields and realize stable operation and efficient charge transfer.The experiments showed that high-performance flexible OFETs were mainly attributed to the synthesized polymers through molecular structure designing which not only have high dielectric constant（k>5）and high electrical insulating property but also favor the growth of organic semiconductor films.The flexible OFETs still showed excellent mechanical flexibility,high electrical,thermal and humidity stability.In addition,highly OFETs were applied into a floating-gate memory with fullerene(C₆₀)embedded charge memory layer.They exhibited excellent memory performance with a large memory window（8.5 V）,current ratio（10³）,stable retention（2×10⁴ s）,cyclic endurance（200 cycles）,multi-level memory（over 4 levels）and non-destructivity.