Electrically bistable and non-volatile memory devices based on p-toluenesulfonic-doped poly(triphenylamine)

Abstract

Two novel poly(triphenylamines) (PTPAs) were prepared from 1,4-dibromobenzene, 4,4′-dibromodiphenyl ether and 4-phenoxyaniline, by a Buchwald–Hartwig coupling reaction. The structures of the resulting polymers were fully characterized by FTIR and ¹H NMR. These PTPAs are thermally stable with 5% weight loss over 450 °C and the glass transition temperature (T_g) was found to be 140–149 °C. The resistive switching devices with the configuration Al/PTPA-TsOH/ITO were constructed using the conventional solution coating process. The devices demonstrated bi-directionally switchable WORM memory behavior. The ON/OFF current ratio of these devices was about 10⁶ and the retention times can be as long as 10⁴ s. The mechanism of the resistance switching effects of the devices can be understood on the basis of the electric field-induced doping effect, which would provide a guideline for designing new materials with high-performance memories.