Regulating the electrical resistive switching behaviors of polyimides through different steric hindrance substituents on 2,7-position of tetraphenyl fluorene diamines moieties

Abstract

Three novel polyimides (PI(TPF-Br BPDA), PI(TPF-Ph BPDA), and PI(TPF-Ph-OMe BPDA)) with tetraphenyl fluorene (TPF) were synthesized and tested. The laboratorial results showed that the constructed electronic devices exhibited different memory behaviors due to the different steric hindrance substituents (bromine atom, phenyl, and 3,5-dimethoxyphenyl) in 2,7-position of TPF molecule. The memorizers based on PI(TPF-Br BPDA) and PI(TPF-Ph BPDA) presented volatile dynamic random access memory (DRAM) feature with turn-on voltages of −2.39 and +1.45 V, as same as −1.71 and +1.74 V, separately. However, the PI(TPF-Ph-OMe BPDA) based apparatus exhibited non-volatile write-once read-many-times memory (WORM) behavior with turn-on voltage of −1.13 V, due to the more charge traps of 3,5-dimethoxyphenyl moieties and higher dipole moment. The switching mechanism was verified by quantum simulation of energy level, electrostatic potential (ESP) surface and dipole moment. These results indicated that the electrical memory performance of the synthesized TPF-based PIs could be adjusted by modifying the electron donor structure.

Memory characteristics of anthracene-based polyimides in non-volatile resistive memory devices

“…[10][11][12][13][14][15] Among them polyimides (PIs) have attracted significant attention as an active layer for memory devices due to their many advantages, including outstanding thermal stability, good dimensional stability, excellent processability, and superior electrical properties. [16][17][18][19][20][21][22][23][24][25][26][27][28][29] High dimensional thermal stability is required to prevent delamination upon the thermal treatment of the memory devices. 30 Regarding processability, the advantage is that devices can be made using simple methods such as spin coating, without using vacuum deposition equipment that is commonly used for memory device research and development.…”