Synthesis And Electrical Memory Characteristics Of Terminally Functionalized Nitrogen-containing Polymers

Memory devices based on the traditional silicon-based inorganic materials aredifficult to fulfill the requirements of high density data storage requirements due to theirown physical and economic deficiencies. It has been unable to meet the needs of socialdevelopment. In recent years, a great deal of effort has been devoted to developing newmaterials for data storage. The advantages of easy fabrication, structural flexibility, highmechanical behavior and good scalability of polymers have attracted considerable attentionin preparation of electrical memory devices. However, the researches of materials is still ininfancy, rational design for functional materials to enhance the performance of the memorydevice is still worthy of studying. In this thesis, a series of azobenzene polymers andnaphthalimide polymers were designed and synthesized. We successfully optimized theperformance of the device by adjusting the molecular structures.1. We studied the impact of conjugation length and terminal electron moieties ofazobenzene molecules on the electrical memory performance of the device. We found thatthe introduction of the effective electron-donor terminal group was conduced to decreasethe turn-on threshold voltage and achieve the advantages of low-power consumption. Theresults provided a certain significance for the research of low-power electrical memorydevices. The long conjugation length of azobenzene molecules was designed for the stablememory property. In addition, the corresponding homopolymers were prepared. Polymershave successfully retained the storage performance of organic molecules. Thus, from theperspective of device fabrication to consider, we have successfully achieved the advantagesof easy fabrication.2. In view of the strong electron-withdrawing ability of the azobenzene and cyanocontributing to the WORM-type devices in the first system, naphthalimide was chose ascharge traps due to the weak electron-withdrawing ability. End functional group polymerNPVCz was prepared by ATRP polymerization. For the first time, we studied the impact of the end functional group on the electrical memory performance of materials. Experimentsfound that the introduction of the naphthalimide end functional group was conduced tochange the tunable memory performance from WORM to flash. It made a usefulexploration for the future regulation of electrical storage type.3. We further designed the naphthalimide group in the polymer side chain andoxadiazole end functional group was introduced to study the impact of end functionalgroup on the memory performance of the device. We found that the device broken throughthe traditional binary mechanism and exhibited ternary memory behaviors withlow-conductivity, intermediate-conductivity, and high-conductivity. In addition, the filmswere treated by different annealing temperature and we studied the impact of annealingtemperature on the electrical memory performance of the device. Experiments found thatthe process of annealing was conduced to improve the film-forming. Lower turn-onthreshold voltage were achieved when the annealing temperature increased. The memorydevice preserved ternary storage performance at different annealing temperature. Theabove results provided a certain significance for the research of thermal stable electricalmemory devices based on polymer materials.