Synthesis And Electrical Memory Characteristics Of Small Molecule Monomers And Polymers Containing Pyrene And Naphthalene

Based on the traditional binary semiconductor storage due to the limitations of the size of its transistors, its storage density has been to the limit, can not meet the need s of development needs of today’s society. Polymers with various low cost film forming method(spraying, roller coating, spin coating, printing, etc.), good scalability and mechanical strength with potential application prospect, attracted the attention of researchers all over the world in the field of information storage. But the mostly polymer material based memory devices with binary memory system, can only be linear increase memory cell’s storage density by reducing the size of the device and the use of multi-level devices. Multilevel memory based on polymer materials less reported, is still in the initial stage of theoretical research.Therefore, we need to well-designed polymer materials to achieve multilevel storage. In this paper,we designed and synthesized small molecule monomers and polymers containing pyrene and naphthalimide to achieve control and optimize storage performance by regulating the molecular groups.1) PMNPE and PMPPE containing pyrene and naphthalene were synthesized by atom transfer radical polymerization(ATRP). Through the I-V measurement of PMNPE and PMPPE, the performance of PMNPE and PMPPE show binary WORM memory behavior and the ternary SRAM memory behavior, respectively. The thermodynamic properties(TGA and DSC), structure characterization(AFM and XRD), optical properties(UV) and electrochemical properties(CV) were characterized for the polymer PMNPE and PMPPE. The results showed that PMNPE shows amorphous, so the configuration inversion of naphthalene ring in the whole conjugated system is difficult, charge transfer mainly based on storage mechanism, and this charge transfer is irreversible under electric field, so PMNPE showing binary WORM storage; Pyrene conjugated plane is much bigger than naphthalene, PMPPE exist some micro-crystal structure, so the inversion of configuration is easy under electric field, the storage mechanism mainly is inversion of configuration and charge transfer, and the inversion of configuration is to respond, so PMPPE show s ternary SRAM memory performance, which also provides reference for our future study of multilevel data storage.2) In this paper, the functional polymer(PVB) containing aldehyde group was first synthesized by ATRP method.4-Hydrazino-1,8-Naphthaliimide and 4-Nitrophenylhydrazine as the electron withdrawing ability of different groups,to graft polymer PVB in different proportions due to the reaction of aldehyde group and hydrazine group under mild conditions, named PVB-DHI, PVB-DHI4-NPH, PVB-DHI-NPH4, PVB-NPH, respectively. The PVB-DHI shows binary DRAM memory behavior, PVB-DHI4-NPH shows ternary WORM memory performance, PVB-DHINPH4 and PVB-NPH show binary WORM memory behavior, which suggesting that PVB as a function polymer backbone, regulation of the grafting ratio of naphthalimide and nitro, so as to achieve the two different degree of charge transfer and from binary to ternary memory.3) We synthesized three different length of alkyl chain bridge double naphthalimide hydrazone type molecular, namely 1.1-2Ni, 1.2-2Ni and 1.3-2Ni. They contain the same electron donating groups and electron withdrawing groups, but because of the different accumulation of three molecules, the storage behavior is different. The molecules of 1.1-2Ni presented amorphous molecular packing, under the electric field induced charge transfer complex slow recovery to the initial after the withdrawal of the electric field, showing binary SRAM memory behavior; Due to the presence of naphthalimide π-π stacking between 1.2-2Ni molecules, equivalent to the formation of a stronger electron withdrawing ability groups, with the formation of stable charge transfer complex in the field, did not respond to the initial state of the withdrawal of the electric field, after the reverse voltage is applied, the memory device before resuming from the high conductivity state back to the initial state, showing binary Flash memory performance; The intermolecular π-π stacking between 1.3-2Ni, more conducive to the carrier transmission, memory device can quickly from the high conductivity state back to the initial state, showing binary DRAM memory performance.