title: The steric effect of aromatic pendant groups and electrical bistability in π-stacked polymers for memory devices.
abstract: In order to investigate the steric effect of aromatic pendant groups and the electrical bistability in nonconjugated polymers potentially for memory device applications, two π-stacked polymers with different steric structures are synthesized and characterized. They exhibit two conductivity states and can be switched from an initial low-conductivity (OFF) state to a high-conductivity (ON) state. Additionally, they demonstrate nonvolatile write-once-read-many-times (WORM) memory behavior with an ON/OFF current ratio up to 10(4), and flash memory behavior with an ON/OFF current ratio of approximately 10(5). Both steady-state and time-resolved fluorescence spectroscopies are used to examine the conformational change of the polymers responding to an applied external electrical voltage. The results provide useful information on different steric effects of pendant groups in polymer chains, resulting in various electrical behaviors. The possibility in realizing an "erasable" behavior through breaking π-stacked structures of pendant groups by a reversal of the electric field was also discussed on the basis of temperature-dependent fluorescence spectroscopy investigation. These results may thus offer a guideline for the design of practical polymer memory devices via tuning steric structure of π-stacked polymers.
authors.affiliation: Key Lab Polymer Composite & Funct Mat, DSAPM Lab, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Yujie
authors.initials: Y
authors.lastname: Chen
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xudong
authors.initials: X
authors.lastname: Chen
authors.forename: Zhenguo
authors.initials: Z
authors.lastname: Chi
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.forename: Jiemei
authors.initials: J
authors.lastname: Ou
authors.forename: Ming Qiu
authors.initials: MQ
authors.lastname: Zhang
authors.forename: Dehao
authors.initials: D
authors.lastname: Li
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Mingkai
authors.initials: M
authors.lastname: Liu
authors.forename: Juying
authors.initials: J
authors.lastname: Zhou